Add NUM_RUNOUT_SENSORS to example configs

Marlin/src/config/default/Configuration.h

@@ -852,15 +852,16 @@
 #endif
 
 /**
- * Filament Runout Sensor
+ * Filament Runout Sensors
- * A mechanical or opto endstop is used to check for the presence of filament.
+ * Mechanical or opto endstops are used to check for the presence of filament.
  *
- * RAMPS-based boards use SERVO3_PIN.
+ * RAMPS-based boards use SERVO3_PIN for the first runout sensor.
- * For other boards you may need to define FIL_RUNOUT_PIN.
+ * For other boards you may need to define FIL_RUNOUT_PIN, FIL_RUNOUT2_PIN, etc.
- * By default the firmware assumes HIGH = has filament, LOW = ran out
+ * By default the firmware assumes HIGH=FILAMENT PRESENT.
  */
 //#define FILAMENT_RUNOUT_SENSOR
 #if ENABLED(FILAMENT_RUNOUT_SENSOR)
+  #define NUM_RUNOUT_SENSORS   1     // Number of sensors, up to one per extruder. Define a FIL_RUNOUT#_PIN for each.
   #define FIL_RUNOUT_INVERTING false // set to true to invert the logic of the sensor.
   #define FIL_RUNOUT_PULLUP          // Use internal pullup for filament runout pins.
   //#define FIL_RUNOUT_PULLDOWN      // Use internal pulldown for filament runout pins.

Marlin/src/config/examples/AlephObjects/TAZ4/Configuration.h

@@ -872,15 +872,16 @@
 #endif
 
 /**
- * Filament Runout Sensor
+ * Filament Runout Sensors
- * A mechanical or opto endstop is used to check for the presence of filament.
+ * Mechanical or opto endstops are used to check for the presence of filament.
  *
- * RAMPS-based boards use SERVO3_PIN.
+ * RAMPS-based boards use SERVO3_PIN for the first runout sensor.
- * For other boards you may need to define FIL_RUNOUT_PIN.
+ * For other boards you may need to define FIL_RUNOUT_PIN, FIL_RUNOUT2_PIN, etc.
- * By default the firmware assumes HIGH = has filament, LOW = ran out
+ * By default the firmware assumes HIGH=FILAMENT PRESENT.
  */
 //#define FILAMENT_RUNOUT_SENSOR
 #if ENABLED(FILAMENT_RUNOUT_SENSOR)
+  #define NUM_RUNOUT_SENSORS   1     // Number of sensors, up to one per extruder. Define a FIL_RUNOUT#_PIN for each.
   #define FIL_RUNOUT_INVERTING false // set to true to invert the logic of the sensor.
   #define FIL_RUNOUT_PULLUP          // Use internal pullup for filament runout pins.
   //#define FIL_RUNOUT_PULLDOWN      // Use internal pulldown for filament runout pins.

Marlin/src/config/examples/AliExpress/CL-260/Configuration.h

@@ -852,15 +852,16 @@
 #endif
 
 /**
- * Filament Runout Sensor
+ * Filament Runout Sensors
- * A mechanical or opto endstop is used to check for the presence of filament.
+ * Mechanical or opto endstops are used to check for the presence of filament.
  *
- * RAMPS-based boards use SERVO3_PIN.
+ * RAMPS-based boards use SERVO3_PIN for the first runout sensor.
- * For other boards you may need to define FIL_RUNOUT_PIN.
+ * For other boards you may need to define FIL_RUNOUT_PIN, FIL_RUNOUT2_PIN, etc.
- * By default the firmware assumes HIGH = has filament, LOW = ran out
+ * By default the firmware assumes HIGH=FILAMENT PRESENT.
  */
 //#define FILAMENT_RUNOUT_SENSOR
 #if ENABLED(FILAMENT_RUNOUT_SENSOR)
+  #define NUM_RUNOUT_SENSORS   1     // Number of sensors, up to one per extruder. Define a FIL_RUNOUT#_PIN for each.
   #define FIL_RUNOUT_INVERTING false // set to true to invert the logic of the sensor.
   #define FIL_RUNOUT_PULLUP          // Use internal pullup for filament runout pins.
   //#define FIL_RUNOUT_PULLDOWN      // Use internal pulldown for filament runout pins.

Marlin/src/config/examples/Anet/A6/Configuration.h

@@ -962,15 +962,16 @@
 #endif
 
 /**
- * Filament Runout Sensor
+ * Filament Runout Sensors
- * A mechanical or opto endstop is used to check for the presence of filament.
+ * Mechanical or opto endstops are used to check for the presence of filament.
  *
- * RAMPS-based boards use SERVO3_PIN.
+ * RAMPS-based boards use SERVO3_PIN for the first runout sensor.
- * For other boards you may need to define FIL_RUNOUT_PIN.
+ * For other boards you may need to define FIL_RUNOUT_PIN, FIL_RUNOUT2_PIN, etc.
- * By default the firmware assumes HIGH = has filament, LOW = ran out
+ * By default the firmware assumes HIGH=FILAMENT PRESENT.
  */
 //#define FILAMENT_RUNOUT_SENSOR
 #if ENABLED(FILAMENT_RUNOUT_SENSOR)
+  #define NUM_RUNOUT_SENSORS   1     // Number of sensors, up to one per extruder. Define a FIL_RUNOUT#_PIN for each.
   #define FIL_RUNOUT_INVERTING false // set to true to invert the logic of the sensor.
   #define FIL_RUNOUT_PULLUP          // Use internal pullup for filament runout pins.
   //#define FIL_RUNOUT_PULLDOWN      // Use internal pulldown for filament runout pins.

Marlin/src/config/examples/Anet/A8/Configuration.h

@@ -859,15 +859,16 @@
 #endif
 
 /**
- * Filament Runout Sensor
+ * Filament Runout Sensors
- * A mechanical or opto endstop is used to check for the presence of filament.
+ * Mechanical or opto endstops are used to check for the presence of filament.
  *
- * RAMPS-based boards use SERVO3_PIN.
+ * RAMPS-based boards use SERVO3_PIN for the first runout sensor.
- * For other boards you may need to define FIL_RUNOUT_PIN.
+ * For other boards you may need to define FIL_RUNOUT_PIN, FIL_RUNOUT2_PIN, etc.
- * By default the firmware assumes HIGH = has filament, LOW = ran out
+ * By default the firmware assumes HIGH=FILAMENT PRESENT.
  */
 //#define FILAMENT_RUNOUT_SENSOR
 #if ENABLED(FILAMENT_RUNOUT_SENSOR)
+  #define NUM_RUNOUT_SENSORS   1     // Number of sensors, up to one per extruder. Define a FIL_RUNOUT#_PIN for each.
   #define FIL_RUNOUT_INVERTING false // set to true to invert the logic of the sensor.
   #define FIL_RUNOUT_PULLUP          // Use internal pullup for filament runout pins.
   //#define FIL_RUNOUT_PULLDOWN      // Use internal pulldown for filament runout pins.

Marlin/src/config/examples/Azteeg/X5GT/Configuration.h

@@ -852,15 +852,16 @@
 #endif
 
 /**
- * Filament Runout Sensor
+ * Filament Runout Sensors
- * A mechanical or opto endstop is used to check for the presence of filament.
+ * Mechanical or opto endstops are used to check for the presence of filament.
  *
- * RAMPS-based boards use SERVO3_PIN.
+ * RAMPS-based boards use SERVO3_PIN for the first runout sensor.
- * For other boards you may need to define FIL_RUNOUT_PIN.
+ * For other boards you may need to define FIL_RUNOUT_PIN, FIL_RUNOUT2_PIN, etc.
- * By default the firmware assumes HIGH = has filament, LOW = ran out
+ * By default the firmware assumes HIGH=FILAMENT PRESENT.
  */
 //#define FILAMENT_RUNOUT_SENSOR
 #if ENABLED(FILAMENT_RUNOUT_SENSOR)
+  #define NUM_RUNOUT_SENSORS   1     // Number of sensors, up to one per extruder. Define a FIL_RUNOUT#_PIN for each.
   #define FIL_RUNOUT_INVERTING false // set to true to invert the logic of the sensor.
   #define FIL_RUNOUT_PULLUP          // Use internal pullup for filament runout pins.
   //#define FIL_RUNOUT_PULLDOWN      // Use internal pulldown for filament runout pins.

Marlin/src/config/examples/BIBO/TouchX/cyclops/Configuration.h

@@ -852,15 +852,16 @@ const bool Z_MIN_PROBE_ENDSTOP_INVERTING = true; // set to true to invert the lo
 #endif
 
 /**
- * Filament Runout Sensor
+ * Filament Runout Sensors
- * A mechanical or opto endstop is used to check for the presence of filament.
+ * Mechanical or opto endstops are used to check for the presence of filament.
  *
- * RAMPS-based boards use SERVO3_PIN.
+ * RAMPS-based boards use SERVO3_PIN for the first runout sensor.
- * For other boards you may need to define FIL_RUNOUT_PIN.
+ * For other boards you may need to define FIL_RUNOUT_PIN, FIL_RUNOUT2_PIN, etc.
- * By default the firmware assumes HIGH = has filament, LOW = ran out
+ * By default the firmware assumes HIGH=FILAMENT PRESENT.
  */
 //#define FILAMENT_RUNOUT_SENSOR
 #if ENABLED(FILAMENT_RUNOUT_SENSOR)
+  #define NUM_RUNOUT_SENSORS   1     // Number of sensors, up to one per extruder. Define a FIL_RUNOUT#_PIN for each.
   #define FIL_RUNOUT_INVERTING false // set to true to invert the logic of the sensor.
   #define FIL_RUNOUT_PULLUP          // Use internal pullup for filament runout pins.
   //#define FIL_RUNOUT_PULLDOWN      // Use internal pulldown for filament runout pins.

Marlin/src/config/examples/BIBO/TouchX/default/Configuration.h

@@ -852,15 +852,16 @@ const bool Z_MIN_PROBE_ENDSTOP_INVERTING = true; // set to true to invert the lo
 #endif
 
 /**
- * Filament Runout Sensor
+ * Filament Runout Sensors
- * A mechanical or opto endstop is used to check for the presence of filament.
+ * Mechanical or opto endstops are used to check for the presence of filament.
  *
- * RAMPS-based boards use SERVO3_PIN.
+ * RAMPS-based boards use SERVO3_PIN for the first runout sensor.
- * For other boards you may need to define FIL_RUNOUT_PIN.
+ * For other boards you may need to define FIL_RUNOUT_PIN, FIL_RUNOUT2_PIN, etc.
- * By default the firmware assumes HIGH = has filament, LOW = ran out
+ * By default the firmware assumes HIGH=FILAMENT PRESENT.
  */
 //#define FILAMENT_RUNOUT_SENSOR
 #if ENABLED(FILAMENT_RUNOUT_SENSOR)
+  #define NUM_RUNOUT_SENSORS   1     // Number of sensors, up to one per extruder. Define a FIL_RUNOUT#_PIN for each.
   #define FIL_RUNOUT_INVERTING false // set to true to invert the logic of the sensor.
   #define FIL_RUNOUT_PULLUP          // Use internal pullup for filament runout pins.
   //#define FIL_RUNOUT_PULLDOWN      // Use internal pulldown for filament runout pins.

Marlin/src/config/examples/BQ/Hephestos/Configuration.h

@@ -840,15 +840,16 @@
 #endif
 
 /**
- * Filament Runout Sensor
+ * Filament Runout Sensors
- * A mechanical or opto endstop is used to check for the presence of filament.
+ * Mechanical or opto endstops are used to check for the presence of filament.
  *
- * RAMPS-based boards use SERVO3_PIN.
+ * RAMPS-based boards use SERVO3_PIN for the first runout sensor.
- * For other boards you may need to define FIL_RUNOUT_PIN.
+ * For other boards you may need to define FIL_RUNOUT_PIN, FIL_RUNOUT2_PIN, etc.
- * By default the firmware assumes HIGH = has filament, LOW = ran out
+ * By default the firmware assumes HIGH=FILAMENT PRESENT.
  */
 //#define FILAMENT_RUNOUT_SENSOR
 #if ENABLED(FILAMENT_RUNOUT_SENSOR)
+  #define NUM_RUNOUT_SENSORS   1     // Number of sensors, up to one per extruder. Define a FIL_RUNOUT#_PIN for each.
   #define FIL_RUNOUT_INVERTING false // set to true to invert the logic of the sensor.
   #define FIL_RUNOUT_PULLUP          // Use internal pullup for filament runout pins.
   //#define FIL_RUNOUT_PULLDOWN      // Use internal pulldown for filament runout pins.

Marlin/src/config/examples/BQ/Hephestos_2/Configuration.h

@@ -853,15 +853,16 @@
 #endif
 
 /**
- * Filament Runout Sensor
+ * Filament Runout Sensors
- * A mechanical or opto endstop is used to check for the presence of filament.
+ * Mechanical or opto endstops are used to check for the presence of filament.
  *
- * RAMPS-based boards use SERVO3_PIN.
+ * RAMPS-based boards use SERVO3_PIN for the first runout sensor.
- * For other boards you may need to define FIL_RUNOUT_PIN.
+ * For other boards you may need to define FIL_RUNOUT_PIN, FIL_RUNOUT2_PIN, etc.
- * By default the firmware assumes HIGH = has filament, LOW = ran out
+ * By default the firmware assumes HIGH=FILAMENT PRESENT.
  */
 //#define FILAMENT_RUNOUT_SENSOR
 #if ENABLED(FILAMENT_RUNOUT_SENSOR)
+  #define NUM_RUNOUT_SENSORS   1     // Number of sensors, up to one per extruder. Define a FIL_RUNOUT#_PIN for each.
   #define FIL_RUNOUT_INVERTING false // set to true to invert the logic of the sensor.
   #define FIL_RUNOUT_PULLUP          // Use internal pullup for filament runout pins.
   //#define FIL_RUNOUT_PULLDOWN      // Use internal pulldown for filament runout pins.

Marlin/src/config/examples/BQ/WITBOX/Configuration.h

@@ -840,15 +840,16 @@
 #endif
 
 /**
- * Filament Runout Sensor
+ * Filament Runout Sensors
- * A mechanical or opto endstop is used to check for the presence of filament.
+ * Mechanical or opto endstops are used to check for the presence of filament.
  *
- * RAMPS-based boards use SERVO3_PIN.
+ * RAMPS-based boards use SERVO3_PIN for the first runout sensor.
- * For other boards you may need to define FIL_RUNOUT_PIN.
+ * For other boards you may need to define FIL_RUNOUT_PIN, FIL_RUNOUT2_PIN, etc.
- * By default the firmware assumes HIGH = has filament, LOW = ran out
+ * By default the firmware assumes HIGH=FILAMENT PRESENT.
  */
 //#define FILAMENT_RUNOUT_SENSOR
 #if ENABLED(FILAMENT_RUNOUT_SENSOR)
+  #define NUM_RUNOUT_SENSORS   1     // Number of sensors, up to one per extruder. Define a FIL_RUNOUT#_PIN for each.
   #define FIL_RUNOUT_INVERTING false // set to true to invert the logic of the sensor.
   #define FIL_RUNOUT_PULLUP          // Use internal pullup for filament runout pins.
   //#define FIL_RUNOUT_PULLDOWN      // Use internal pulldown for filament runout pins.

Marlin/src/config/examples/Cartesio/Configuration.h

@@ -851,15 +851,16 @@
 #endif
 
 /**
- * Filament Runout Sensor
+ * Filament Runout Sensors
- * A mechanical or opto endstop is used to check for the presence of filament.
+ * Mechanical or opto endstops are used to check for the presence of filament.
  *
- * RAMPS-based boards use SERVO3_PIN.
+ * RAMPS-based boards use SERVO3_PIN for the first runout sensor.
- * For other boards you may need to define FIL_RUNOUT_PIN.
+ * For other boards you may need to define FIL_RUNOUT_PIN, FIL_RUNOUT2_PIN, etc.
- * By default the firmware assumes HIGH = has filament, LOW = ran out
+ * By default the firmware assumes HIGH=FILAMENT PRESENT.
  */
 //#define FILAMENT_RUNOUT_SENSOR
 #if ENABLED(FILAMENT_RUNOUT_SENSOR)
+  #define NUM_RUNOUT_SENSORS   1     // Number of sensors, up to one per extruder. Define a FIL_RUNOUT#_PIN for each.
   #define FIL_RUNOUT_INVERTING false // set to true to invert the logic of the sensor.
   #define FIL_RUNOUT_PULLUP          // Use internal pullup for filament runout pins.
   //#define FIL_RUNOUT_PULLDOWN      // Use internal pulldown for filament runout pins.

Marlin/src/config/examples/Creality/CR-10/Configuration.h

@@ -862,15 +862,16 @@
 #endif
 
 /**
- * Filament Runout Sensor
+ * Filament Runout Sensors
- * A mechanical or opto endstop is used to check for the presence of filament.
+ * Mechanical or opto endstops are used to check for the presence of filament.
  *
- * RAMPS-based boards use SERVO3_PIN.
+ * RAMPS-based boards use SERVO3_PIN for the first runout sensor.
- * For other boards you may need to define FIL_RUNOUT_PIN.
+ * For other boards you may need to define FIL_RUNOUT_PIN, FIL_RUNOUT2_PIN, etc.
- * By default the firmware assumes HIGH = has filament, LOW = ran out
+ * By default the firmware assumes HIGH=FILAMENT PRESENT.
  */
 //#define FILAMENT_RUNOUT_SENSOR
 #if ENABLED(FILAMENT_RUNOUT_SENSOR)
+  #define NUM_RUNOUT_SENSORS   1     // Number of sensors, up to one per extruder. Define a FIL_RUNOUT#_PIN for each.
   #define FIL_RUNOUT_INVERTING false // set to true to invert the logic of the sensor.
   #define FIL_RUNOUT_PULLUP          // Use internal pullup for filament runout pins.
   //#define FIL_RUNOUT_PULLDOWN      // Use internal pulldown for filament runout pins.

Marlin/src/config/examples/Creality/CR-10S/Configuration.h

@@ -843,15 +843,16 @@
 #endif
 
 /**
- * Filament Runout Sensor
+ * Filament Runout Sensors
- * A mechanical or opto endstop is used to check for the presence of filament.
+ * Mechanical or opto endstops are used to check for the presence of filament.
  *
- * RAMPS-based boards use SERVO3_PIN.
+ * RAMPS-based boards use SERVO3_PIN for the first runout sensor.
- * For other boards you may need to define FIL_RUNOUT_PIN.
+ * For other boards you may need to define FIL_RUNOUT_PIN, FIL_RUNOUT2_PIN, etc.
- * By default the firmware assumes HIGH = has filament, LOW = ran out
+ * By default the firmware assumes HIGH=FILAMENT PRESENT.
  */
 #define FILAMENT_RUNOUT_SENSOR
 #if ENABLED(FILAMENT_RUNOUT_SENSOR)
+  #define NUM_RUNOUT_SENSORS   1     // Number of sensors, up to one per extruder. Define a FIL_RUNOUT#_PIN for each.
   #define FIL_RUNOUT_INVERTING true // set to true to invert the logic of the sensor.
   #define FIL_RUNOUT_PULLUP          // Use internal pullup for filament runout pins.
   //#define FIL_RUNOUT_PULLDOWN      // Use internal pulldown for filament runout pins.

Marlin/src/config/examples/Creality/Ender/Configuration.h

@@ -847,15 +847,16 @@
 #endif
 
 /**
- * Filament Runout Sensor
+ * Filament Runout Sensors
- * A mechanical or opto endstop is used to check for the presence of filament.
+ * Mechanical or opto endstops are used to check for the presence of filament.
  *
- * RAMPS-based boards use SERVO3_PIN.
+ * RAMPS-based boards use SERVO3_PIN for the first runout sensor.
- * For other boards you may need to define FIL_RUNOUT_PIN.
+ * For other boards you may need to define FIL_RUNOUT_PIN, FIL_RUNOUT2_PIN, etc.
- * By default the firmware assumes HIGH = has filament, LOW = ran out
+ * By default the firmware assumes HIGH=FILAMENT PRESENT.
  */
 //#define FILAMENT_RUNOUT_SENSOR
 #if ENABLED(FILAMENT_RUNOUT_SENSOR)
+  #define NUM_RUNOUT_SENSORS   1     // Number of sensors, up to one per extruder. Define a FIL_RUNOUT#_PIN for each.
   #define FIL_RUNOUT_INVERTING false // set to true to invert the logic of the sensor.
   #define FIL_RUNOUT_PULLUP          // Use internal pullup for filament runout pins.
   //#define FIL_RUNOUT_PULLDOWN      // Use internal pulldown for filament runout pins.

Marlin/src/config/examples/Felix/Configuration.h

@@ -834,15 +834,16 @@
 #endif
 
 /**
- * Filament Runout Sensor
+ * Filament Runout Sensors
- * A mechanical or opto endstop is used to check for the presence of filament.
+ * Mechanical or opto endstops are used to check for the presence of filament.
  *
- * RAMPS-based boards use SERVO3_PIN.
+ * RAMPS-based boards use SERVO3_PIN for the first runout sensor.
- * For other boards you may need to define FIL_RUNOUT_PIN.
+ * For other boards you may need to define FIL_RUNOUT_PIN, FIL_RUNOUT2_PIN, etc.
- * By default the firmware assumes HIGH = has filament, LOW = ran out
+ * By default the firmware assumes HIGH=FILAMENT PRESENT.
  */
 //#define FILAMENT_RUNOUT_SENSOR
 #if ENABLED(FILAMENT_RUNOUT_SENSOR)
+  #define NUM_RUNOUT_SENSORS   1     // Number of sensors, up to one per extruder. Define a FIL_RUNOUT#_PIN for each.
   #define FIL_RUNOUT_INVERTING false // set to true to invert the logic of the sensor.
   #define FIL_RUNOUT_PULLUP          // Use internal pullup for filament runout pins.
   //#define FIL_RUNOUT_PULLDOWN      // Use internal pulldown for filament runout pins.

Marlin/src/config/examples/Felix/DUAL/Configuration.h

@@ -834,15 +834,16 @@
 #endif
 
 /**
- * Filament Runout Sensor
+ * Filament Runout Sensors
- * A mechanical or opto endstop is used to check for the presence of filament.
+ * Mechanical or opto endstops are used to check for the presence of filament.
  *
- * RAMPS-based boards use SERVO3_PIN.
+ * RAMPS-based boards use SERVO3_PIN for the first runout sensor.
- * For other boards you may need to define FIL_RUNOUT_PIN.
+ * For other boards you may need to define FIL_RUNOUT_PIN, FIL_RUNOUT2_PIN, etc.
- * By default the firmware assumes HIGH = has filament, LOW = ran out
+ * By default the firmware assumes HIGH=FILAMENT PRESENT.
  */
 //#define FILAMENT_RUNOUT_SENSOR
 #if ENABLED(FILAMENT_RUNOUT_SENSOR)
+  #define NUM_RUNOUT_SENSORS   1     // Number of sensors, up to one per extruder. Define a FIL_RUNOUT#_PIN for each.
   #define FIL_RUNOUT_INVERTING false // set to true to invert the logic of the sensor.
   #define FIL_RUNOUT_PULLUP          // Use internal pullup for filament runout pins.
   //#define FIL_RUNOUT_PULLDOWN      // Use internal pulldown for filament runout pins.

Marlin/src/config/examples/FolgerTech/i3-2020/Configuration.h

@@ -858,15 +858,16 @@
 #endif
 
 /**
- * Filament Runout Sensor
+ * Filament Runout Sensors
- * A mechanical or opto endstop is used to check for the presence of filament.
+ * Mechanical or opto endstops are used to check for the presence of filament.
  *
- * RAMPS-based boards use SERVO3_PIN.
+ * RAMPS-based boards use SERVO3_PIN for the first runout sensor.
- * For other boards you may need to define FIL_RUNOUT_PIN.
+ * For other boards you may need to define FIL_RUNOUT_PIN, FIL_RUNOUT2_PIN, etc.
- * By default the firmware assumes HIGH = has filament, LOW = ran out
+ * By default the firmware assumes HIGH=FILAMENT PRESENT.
  */
 //#define FILAMENT_RUNOUT_SENSOR
 #if ENABLED(FILAMENT_RUNOUT_SENSOR)
+  #define NUM_RUNOUT_SENSORS   1     // Number of sensors, up to one per extruder. Define a FIL_RUNOUT#_PIN for each.
   #define FIL_RUNOUT_INVERTING false // set to true to invert the logic of the sensor.
   #define FIL_RUNOUT_PULLUP          // Use internal pullup for filament runout pins.
   //#define FIL_RUNOUT_PULLDOWN      // Use internal pulldown for filament runout pins.

Marlin/src/config/examples/Geeetech/GT2560/Configuration.h

@@ -867,15 +867,16 @@
 #endif
 
 /**
- * Filament Runout Sensor
+ * Filament Runout Sensors
- * A mechanical or opto endstop is used to check for the presence of filament.
+ * Mechanical or opto endstops are used to check for the presence of filament.
  *
- * RAMPS-based boards use SERVO3_PIN.
+ * RAMPS-based boards use SERVO3_PIN for the first runout sensor.
- * For other boards you may need to define FIL_RUNOUT_PIN.
+ * For other boards you may need to define FIL_RUNOUT_PIN, FIL_RUNOUT2_PIN, etc.
- * By default the firmware assumes HIGH = has filament, LOW = ran out
+ * By default the firmware assumes HIGH=FILAMENT PRESENT.
  */
 //#define FILAMENT_RUNOUT_SENSOR
 #if ENABLED(FILAMENT_RUNOUT_SENSOR)
+  #define NUM_RUNOUT_SENSORS   1     // Number of sensors, up to one per extruder. Define a FIL_RUNOUT#_PIN for each.
   #define FIL_RUNOUT_INVERTING false // set to true to invert the logic of the sensor.
   #define FIL_RUNOUT_PULLUP          // Use internal pullup for filament runout pins.
   //#define FIL_RUNOUT_PULLDOWN      // Use internal pulldown for filament runout pins.

Marlin/src/config/examples/Geeetech/I3_Pro_X-GT2560/Configuration.h

@@ -852,15 +852,16 @@
 #endif
 
 /**
- * Filament Runout Sensor
+ * Filament Runout Sensors
- * A mechanical or opto endstop is used to check for the presence of filament.
+ * Mechanical or opto endstops are used to check for the presence of filament.
  *
- * RAMPS-based boards use SERVO3_PIN.
+ * RAMPS-based boards use SERVO3_PIN for the first runout sensor.
- * For other boards you may need to define FIL_RUNOUT_PIN.
+ * For other boards you may need to define FIL_RUNOUT_PIN, FIL_RUNOUT2_PIN, etc.
- * By default the firmware assumes HIGH = has filament, LOW = ran out
+ * By default the firmware assumes HIGH=FILAMENT PRESENT.
  */
 //#define FILAMENT_RUNOUT_SENSOR
 #if ENABLED(FILAMENT_RUNOUT_SENSOR)
+  #define NUM_RUNOUT_SENSORS   1     // Number of sensors, up to one per extruder. Define a FIL_RUNOUT#_PIN for each.
   #define FIL_RUNOUT_INVERTING false // set to true to invert the logic of the sensor.
   #define FIL_RUNOUT_PULLUP          // Use internal pullup for filament runout pins.
   //#define FIL_RUNOUT_PULLDOWN      // Use internal pulldown for filament runout pins.

Marlin/src/config/examples/Geeetech/Prusa i3 Pro B/bltouch/Configuration.h

@@ -859,15 +859,16 @@
 #endif
 
 /**
- * Filament Runout Sensor
+ * Filament Runout Sensors
- * A mechanical or opto endstop is used to check for the presence of filament.
+ * Mechanical or opto endstops are used to check for the presence of filament.
  *
- * RAMPS-based boards use SERVO3_PIN.
+ * RAMPS-based boards use SERVO3_PIN for the first runout sensor.
- * For other boards you may need to define FIL_RUNOUT_PIN.
+ * For other boards you may need to define FIL_RUNOUT_PIN, FIL_RUNOUT2_PIN, etc.
- * By default the firmware assumes HIGH = has filament, LOW = ran out
+ * By default the firmware assumes HIGH=FILAMENT PRESENT.
  */
 //#define FILAMENT_RUNOUT_SENSOR
 #if ENABLED(FILAMENT_RUNOUT_SENSOR)
+  #define NUM_RUNOUT_SENSORS   1     // Number of sensors, up to one per extruder. Define a FIL_RUNOUT#_PIN for each.
   #define FIL_RUNOUT_INVERTING false // set to true to invert the logic of the sensor.
   #define FIL_RUNOUT_PULLUP          // Use internal pullup for filament runout pins.
   //#define FIL_RUNOUT_PULLDOWN      // Use internal pulldown for filament runout pins.

Marlin/src/config/examples/Geeetech/Prusa i3 Pro B/noprobe/Configuration.h

@@ -858,15 +858,16 @@
 #endif
 
 /**
- * Filament Runout Sensor
+ * Filament Runout Sensors
- * A mechanical or opto endstop is used to check for the presence of filament.
+ * Mechanical or opto endstops are used to check for the presence of filament.
  *
- * RAMPS-based boards use SERVO3_PIN.
+ * RAMPS-based boards use SERVO3_PIN for the first runout sensor.
- * For other boards you may need to define FIL_RUNOUT_PIN.
+ * For other boards you may need to define FIL_RUNOUT_PIN, FIL_RUNOUT2_PIN, etc.
- * By default the firmware assumes HIGH = has filament, LOW = ran out
+ * By default the firmware assumes HIGH=FILAMENT PRESENT.
  */
 //#define FILAMENT_RUNOUT_SENSOR
 #if ENABLED(FILAMENT_RUNOUT_SENSOR)
+  #define NUM_RUNOUT_SENSORS   1     // Number of sensors, up to one per extruder. Define a FIL_RUNOUT#_PIN for each.
   #define FIL_RUNOUT_INVERTING false // set to true to invert the logic of the sensor.
   #define FIL_RUNOUT_PULLUP          // Use internal pullup for filament runout pins.
   //#define FIL_RUNOUT_PULLDOWN      // Use internal pulldown for filament runout pins.

Marlin/src/config/examples/Infitary/i3-M508/Configuration.h

@@ -856,15 +856,16 @@
 #endif
 
 /**
- * Filament Runout Sensor
+ * Filament Runout Sensors
- * A mechanical or opto endstop is used to check for the presence of filament.
+ * Mechanical or opto endstops are used to check for the presence of filament.
  *
- * RAMPS-based boards use SERVO3_PIN.
+ * RAMPS-based boards use SERVO3_PIN for the first runout sensor.
- * For other boards you may need to define FIL_RUNOUT_PIN.
+ * For other boards you may need to define FIL_RUNOUT_PIN, FIL_RUNOUT2_PIN, etc.
- * By default the firmware assumes HIGH = has filament, LOW = ran out
+ * By default the firmware assumes HIGH=FILAMENT PRESENT.
  */
 //#define FILAMENT_RUNOUT_SENSOR
 #if ENABLED(FILAMENT_RUNOUT_SENSOR)
+  #define NUM_RUNOUT_SENSORS   1     // Number of sensors, up to one per extruder. Define a FIL_RUNOUT#_PIN for each.
   #define FIL_RUNOUT_INVERTING false // set to true to invert the logic of the sensor.
   #define FIL_RUNOUT_PULLUP          // Use internal pullup for filament runout pins.
   //#define FIL_RUNOUT_PULLDOWN      // Use internal pulldown for filament runout pins.

Marlin/src/config/examples/JGAurora/A5/Configuration.h

@@ -864,15 +864,16 @@
 #endif
 
 /**
- * Filament Runout Sensor
+ * Filament Runout Sensors
- * A mechanical or opto endstop is used to check for the presence of filament.
+ * Mechanical or opto endstops are used to check for the presence of filament.
  *
- * RAMPS-based boards use SERVO3_PIN.
+ * RAMPS-based boards use SERVO3_PIN for the first runout sensor.
- * For other boards you may need to define FIL_RUNOUT_PIN.
+ * For other boards you may need to define FIL_RUNOUT_PIN, FIL_RUNOUT2_PIN, etc.
- * By default the firmware assumes HIGH = has filament, LOW = ran out
+ * By default the firmware assumes HIGH=FILAMENT PRESENT.
  */
 #define FILAMENT_RUNOUT_SENSOR
 #if ENABLED(FILAMENT_RUNOUT_SENSOR)
+  #define NUM_RUNOUT_SENSORS   1     // Number of sensors, up to one per extruder. Define a FIL_RUNOUT#_PIN for each.
   #define FIL_RUNOUT_INVERTING false // set to true to invert the logic of the sensor.
   #define FIL_RUNOUT_PULLUP          // Use internal pullup for filament runout pins.
   //#define FIL_RUNOUT_PULLDOWN      // Use internal pulldown for filament runout pins.

Marlin/src/config/examples/MakerParts/Configuration.h

@@ -872,15 +872,16 @@
 #endif
 
 /**
- * Filament Runout Sensor
+ * Filament Runout Sensors
- * A mechanical or opto endstop is used to check for the presence of filament.
+ * Mechanical or opto endstops are used to check for the presence of filament.
  *
- * RAMPS-based boards use SERVO3_PIN.
+ * RAMPS-based boards use SERVO3_PIN for the first runout sensor.
- * For other boards you may need to define FIL_RUNOUT_PIN.
+ * For other boards you may need to define FIL_RUNOUT_PIN, FIL_RUNOUT2_PIN, etc.
- * By default the firmware assumes HIGH = has filament, LOW = ran out
+ * By default the firmware assumes HIGH=FILAMENT PRESENT.
  */
 //#define FILAMENT_RUNOUT_SENSOR
 #if ENABLED(FILAMENT_RUNOUT_SENSOR)
+  #define NUM_RUNOUT_SENSORS   1     // Number of sensors, up to one per extruder. Define a FIL_RUNOUT#_PIN for each.
   #define FIL_RUNOUT_INVERTING false // set to true to invert the logic of the sensor.
   #define FIL_RUNOUT_PULLUP          // Use internal pullup for filament runout pins.
   //#define FIL_RUNOUT_PULLDOWN      // Use internal pulldown for filament runout pins.

Marlin/src/config/examples/Malyan/M150/Configuration.h

@@ -876,15 +876,16 @@
 #endif
 
 /**
- * Filament Runout Sensor
+ * Filament Runout Sensors
- * A mechanical or opto endstop is used to check for the presence of filament.
+ * Mechanical or opto endstops are used to check for the presence of filament.
  *
- * RAMPS-based boards use SERVO3_PIN.
+ * RAMPS-based boards use SERVO3_PIN for the first runout sensor.
- * For other boards you may need to define FIL_RUNOUT_PIN.
+ * For other boards you may need to define FIL_RUNOUT_PIN, FIL_RUNOUT2_PIN, etc.
- * By default the firmware assumes HIGH = has filament, LOW = ran out
+ * By default the firmware assumes HIGH=FILAMENT PRESENT.
  */
 //#define FILAMENT_RUNOUT_SENSOR
 #if ENABLED(FILAMENT_RUNOUT_SENSOR)
+  #define NUM_RUNOUT_SENSORS   1     // Number of sensors, up to one per extruder. Define a FIL_RUNOUT#_PIN for each.
   #define FIL_RUNOUT_INVERTING false // set to true to invert the logic of the sensor.
   #define FIL_RUNOUT_PULLUP          // Use internal pullup for filament runout pins.
   //#define FIL_RUNOUT_PULLDOWN      // Use internal pulldown for filament runout pins.

Marlin/src/config/examples/Malyan/M200/Configuration.h

@@ -851,15 +851,16 @@
 #endif
 
 /**
- * Filament Runout Sensor
+ * Filament Runout Sensors
- * A mechanical or opto endstop is used to check for the presence of filament.
+ * Mechanical or opto endstops are used to check for the presence of filament.
  *
- * RAMPS-based boards use SERVO3_PIN.
+ * RAMPS-based boards use SERVO3_PIN for the first runout sensor.
- * For other boards you may need to define FIL_RUNOUT_PIN.
+ * For other boards you may need to define FIL_RUNOUT_PIN, FIL_RUNOUT2_PIN, etc.
- * By default the firmware assumes HIGH = has filament, LOW = ran out
+ * By default the firmware assumes HIGH=FILAMENT PRESENT.
  */
 //#define FILAMENT_RUNOUT_SENSOR
 #if ENABLED(FILAMENT_RUNOUT_SENSOR)
+  #define NUM_RUNOUT_SENSORS   1     // Number of sensors, up to one per extruder. Define a FIL_RUNOUT#_PIN for each.
   #define FIL_RUNOUT_INVERTING false // set to true to invert the logic of the sensor.
   #define FIL_RUNOUT_PULLUP          // Use internal pullup for filament runout pins.
   //#define FIL_RUNOUT_PULLDOWN      // Use internal pulldown for filament runout pins.

Marlin/src/config/examples/Micromake/C1/basic/Configuration.h

@@ -856,15 +856,16 @@
 #endif
 
 /**
- * Filament Runout Sensor
+ * Filament Runout Sensors
- * A mechanical or opto endstop is used to check for the presence of filament.
+ * Mechanical or opto endstops are used to check for the presence of filament.
  *
- * RAMPS-based boards use SERVO3_PIN.
+ * RAMPS-based boards use SERVO3_PIN for the first runout sensor.
- * For other boards you may need to define FIL_RUNOUT_PIN.
+ * For other boards you may need to define FIL_RUNOUT_PIN, FIL_RUNOUT2_PIN, etc.
- * By default the firmware assumes HIGH = has filament, LOW = ran out
+ * By default the firmware assumes HIGH=FILAMENT PRESENT.
  */
 //#define FILAMENT_RUNOUT_SENSOR
 #if ENABLED(FILAMENT_RUNOUT_SENSOR)
+  #define NUM_RUNOUT_SENSORS   1     // Number of sensors, up to one per extruder. Define a FIL_RUNOUT#_PIN for each.
   #define FIL_RUNOUT_INVERTING false // set to true to invert the logic of the sensor.
   #define FIL_RUNOUT_PULLUP          // Use internal pullup for filament runout pins.
   //#define FIL_RUNOUT_PULLDOWN      // Use internal pulldown for filament runout pins.

Marlin/src/config/examples/Micromake/C1/enhanced/Configuration.h

@@ -856,15 +856,16 @@
 #endif
 
 /**
- * Filament Runout Sensor
+ * Filament Runout Sensors
- * A mechanical or opto endstop is used to check for the presence of filament.
+ * Mechanical or opto endstops are used to check for the presence of filament.
  *
- * RAMPS-based boards use SERVO3_PIN.
+ * RAMPS-based boards use SERVO3_PIN for the first runout sensor.
- * For other boards you may need to define FIL_RUNOUT_PIN.
+ * For other boards you may need to define FIL_RUNOUT_PIN, FIL_RUNOUT2_PIN, etc.
- * By default the firmware assumes HIGH = has filament, LOW = ran out
+ * By default the firmware assumes HIGH=FILAMENT PRESENT.
  */
 //#define FILAMENT_RUNOUT_SENSOR
 #if ENABLED(FILAMENT_RUNOUT_SENSOR)
+  #define NUM_RUNOUT_SENSORS   1     // Number of sensors, up to one per extruder. Define a FIL_RUNOUT#_PIN for each.
   #define FIL_RUNOUT_INVERTING false // set to true to invert the logic of the sensor.
   #define FIL_RUNOUT_PULLUP          // Use internal pullup for filament runout pins.
   //#define FIL_RUNOUT_PULLDOWN      // Use internal pulldown for filament runout pins.

Marlin/src/config/examples/Mks/Sbase/Configuration.h

@@ -852,15 +852,16 @@
 #endif
 
 /**
- * Filament Runout Sensor
+ * Filament Runout Sensors
- * A mechanical or opto endstop is used to check for the presence of filament.
+ * Mechanical or opto endstops are used to check for the presence of filament.
  *
- * RAMPS-based boards use SERVO3_PIN.
+ * RAMPS-based boards use SERVO3_PIN for the first runout sensor.
- * For other boards you may need to define FIL_RUNOUT_PIN.
+ * For other boards you may need to define FIL_RUNOUT_PIN, FIL_RUNOUT2_PIN, etc.
- * By default the firmware assumes HIGH = has filament, LOW = ran out
+ * By default the firmware assumes HIGH=FILAMENT PRESENT.
  */
 //#define FILAMENT_RUNOUT_SENSOR
 #if ENABLED(FILAMENT_RUNOUT_SENSOR)
+  #define NUM_RUNOUT_SENSORS   1     // Number of sensors, up to one per extruder. Define a FIL_RUNOUT#_PIN for each.
   #define FIL_RUNOUT_INVERTING false // set to true to invert the logic of the sensor.
   #define FIL_RUNOUT_PULLUP          // Use internal pullup for filament runout pins.
   //#define FIL_RUNOUT_PULLDOWN      // Use internal pulldown for filament runout pins.

Marlin/src/config/examples/RepRapWorld/Megatronics/Configuration.h

@@ -852,15 +852,16 @@
 #endif
 
 /**
- * Filament Runout Sensor
+ * Filament Runout Sensors
- * A mechanical or opto endstop is used to check for the presence of filament.
+ * Mechanical or opto endstops are used to check for the presence of filament.
  *
- * RAMPS-based boards use SERVO3_PIN.
+ * RAMPS-based boards use SERVO3_PIN for the first runout sensor.
- * For other boards you may need to define FIL_RUNOUT_PIN.
+ * For other boards you may need to define FIL_RUNOUT_PIN, FIL_RUNOUT2_PIN, etc.
- * By default the firmware assumes HIGH = has filament, LOW = ran out
+ * By default the firmware assumes HIGH=FILAMENT PRESENT.
  */
 //#define FILAMENT_RUNOUT_SENSOR
 #if ENABLED(FILAMENT_RUNOUT_SENSOR)
+  #define NUM_RUNOUT_SENSORS   1     // Number of sensors, up to one per extruder. Define a FIL_RUNOUT#_PIN for each.
   #define FIL_RUNOUT_INVERTING false // set to true to invert the logic of the sensor.
   #define FIL_RUNOUT_PULLUP          // Use internal pullup for filament runout pins.
   //#define FIL_RUNOUT_PULLDOWN      // Use internal pulldown for filament runout pins.

Marlin/src/config/examples/RigidBot/Configuration.h

@@ -850,15 +850,16 @@
 #endif
 
 /**
- * Filament Runout Sensor
+ * Filament Runout Sensors
- * A mechanical or opto endstop is used to check for the presence of filament.
+ * Mechanical or opto endstops are used to check for the presence of filament.
  *
- * RAMPS-based boards use SERVO3_PIN.
+ * RAMPS-based boards use SERVO3_PIN for the first runout sensor.
- * For other boards you may need to define FIL_RUNOUT_PIN.
+ * For other boards you may need to define FIL_RUNOUT_PIN, FIL_RUNOUT2_PIN, etc.
- * By default the firmware assumes HIGH = has filament, LOW = ran out
+ * By default the firmware assumes HIGH=FILAMENT PRESENT.
  */
 //#define FILAMENT_RUNOUT_SENSOR
 #if ENABLED(FILAMENT_RUNOUT_SENSOR)
+  #define NUM_RUNOUT_SENSORS   1     // Number of sensors, up to one per extruder. Define a FIL_RUNOUT#_PIN for each.
   #define FIL_RUNOUT_INVERTING false // set to true to invert the logic of the sensor.
   #define FIL_RUNOUT_PULLUP          // Use internal pullup for filament runout pins.
   //#define FIL_RUNOUT_PULLDOWN      // Use internal pulldown for filament runout pins.

Marlin/src/config/examples/SCARA/Configuration.h

@@ -864,15 +864,16 @@
 #endif
 
 /**
- * Filament Runout Sensor
+ * Filament Runout Sensors
- * A mechanical or opto endstop is used to check for the presence of filament.
+ * Mechanical or opto endstops are used to check for the presence of filament.
  *
- * RAMPS-based boards use SERVO3_PIN.
+ * RAMPS-based boards use SERVO3_PIN for the first runout sensor.
- * For other boards you may need to define FIL_RUNOUT_PIN.
+ * For other boards you may need to define FIL_RUNOUT_PIN, FIL_RUNOUT2_PIN, etc.
- * By default the firmware assumes HIGH = has filament, LOW = ran out
+ * By default the firmware assumes HIGH=FILAMENT PRESENT.
  */
 //#define FILAMENT_RUNOUT_SENSOR
 #if ENABLED(FILAMENT_RUNOUT_SENSOR)
+  #define NUM_RUNOUT_SENSORS   1     // Number of sensors, up to one per extruder. Define a FIL_RUNOUT#_PIN for each.
   #define FIL_RUNOUT_INVERTING false // set to true to invert the logic of the sensor.
   #define FIL_RUNOUT_PULLUP          // Use internal pullup for filament runout pins.
   //#define FIL_RUNOUT_PULLDOWN      // Use internal pulldown for filament runout pins.

Marlin/src/config/examples/STM32F10/Configuration.h

@@ -855,15 +855,16 @@
 #endif
 
 /**
- * Filament Runout Sensor
+ * Filament Runout Sensors
- * A mechanical or opto endstop is used to check for the presence of filament.
+ * Mechanical or opto endstops are used to check for the presence of filament.
  *
- * RAMPS-based boards use SERVO3_PIN.
+ * RAMPS-based boards use SERVO3_PIN for the first runout sensor.
- * For other boards you may need to define FIL_RUNOUT_PIN.
+ * For other boards you may need to define FIL_RUNOUT_PIN, FIL_RUNOUT2_PIN, etc.
- * By default the firmware assumes HIGH = has filament, LOW = ran out
+ * By default the firmware assumes HIGH=FILAMENT PRESENT.
  */
 //#define FILAMENT_RUNOUT_SENSOR
 #if ENABLED(FILAMENT_RUNOUT_SENSOR)
+  #define NUM_RUNOUT_SENSORS   1     // Number of sensors, up to one per extruder. Define a FIL_RUNOUT#_PIN for each.
   #define FIL_RUNOUT_INVERTING false // set to true to invert the logic of the sensor.
   #define FIL_RUNOUT_PULLUP          // Use internal pullup for filament runout pins.
   //#define FIL_RUNOUT_PULLDOWN      // Use internal pulldown for filament runout pins.

Marlin/src/config/examples/Sanguinololu/Configuration.h

@@ -883,15 +883,16 @@
 #endif
 
 /**
- * Filament Runout Sensor
+ * Filament Runout Sensors
- * A mechanical or opto endstop is used to check for the presence of filament.
+ * Mechanical or opto endstops are used to check for the presence of filament.
  *
- * RAMPS-based boards use SERVO3_PIN.
+ * RAMPS-based boards use SERVO3_PIN for the first runout sensor.
- * For other boards you may need to define FIL_RUNOUT_PIN.
+ * For other boards you may need to define FIL_RUNOUT_PIN, FIL_RUNOUT2_PIN, etc.
- * By default the firmware assumes HIGH = has filament, LOW = ran out
+ * By default the firmware assumes HIGH=FILAMENT PRESENT.
  */
 //#define FILAMENT_RUNOUT_SENSOR
 #if ENABLED(FILAMENT_RUNOUT_SENSOR)
+  #define NUM_RUNOUT_SENSORS   1     // Number of sensors, up to one per extruder. Define a FIL_RUNOUT#_PIN for each.
   #define FIL_RUNOUT_INVERTING false // set to true to invert the logic of the sensor.
   #define FIL_RUNOUT_PULLUP          // Use internal pullup for filament runout pins.
   //#define FIL_RUNOUT_PULLDOWN      // Use internal pulldown for filament runout pins.

Marlin/src/config/examples/TheBorg/Configuration.h

@@ -852,15 +852,16 @@
 #endif
 
 /**
- * Filament Runout Sensor
+ * Filament Runout Sensors
- * A mechanical or opto endstop is used to check for the presence of filament.
+ * Mechanical or opto endstops are used to check for the presence of filament.
  *
- * RAMPS-based boards use SERVO3_PIN.
+ * RAMPS-based boards use SERVO3_PIN for the first runout sensor.
- * For other boards you may need to define FIL_RUNOUT_PIN.
+ * For other boards you may need to define FIL_RUNOUT_PIN, FIL_RUNOUT2_PIN, etc.
- * By default the firmware assumes HIGH = has filament, LOW = ran out
+ * By default the firmware assumes HIGH=FILAMENT PRESENT.
  */
 //#define FILAMENT_RUNOUT_SENSOR
 #if ENABLED(FILAMENT_RUNOUT_SENSOR)
+  #define NUM_RUNOUT_SENSORS   1     // Number of sensors, up to one per extruder. Define a FIL_RUNOUT#_PIN for each.
   #define FIL_RUNOUT_INVERTING false // set to true to invert the logic of the sensor.
   #define FIL_RUNOUT_PULLUP          // Use internal pullup for filament runout pins.
   //#define FIL_RUNOUT_PULLDOWN      // Use internal pulldown for filament runout pins.

Marlin/src/config/examples/TinyBoy2/Configuration.h

@@ -908,15 +908,16 @@
 #endif
 
 /**
- * Filament Runout Sensor
+ * Filament Runout Sensors
- * A mechanical or opto endstop is used to check for the presence of filament.
+ * Mechanical or opto endstops are used to check for the presence of filament.
  *
- * RAMPS-based boards use SERVO3_PIN.
+ * RAMPS-based boards use SERVO3_PIN for the first runout sensor.
- * For other boards you may need to define FIL_RUNOUT_PIN.
+ * For other boards you may need to define FIL_RUNOUT_PIN, FIL_RUNOUT2_PIN, etc.
- * By default the firmware assumes HIGH = has filament, LOW = ran out
+ * By default the firmware assumes HIGH=FILAMENT PRESENT.
  */
 //#define FILAMENT_RUNOUT_SENSOR
 #if ENABLED(FILAMENT_RUNOUT_SENSOR)
+  #define NUM_RUNOUT_SENSORS   1     // Number of sensors, up to one per extruder. Define a FIL_RUNOUT#_PIN for each.
   #define FIL_RUNOUT_INVERTING false // set to true to invert the logic of the sensor.
   #define FIL_RUNOUT_PULLUP          // Use internal pullup for filament runout pins.
   //#define FIL_RUNOUT_PULLDOWN      // Use internal pulldown for filament runout pins.

Marlin/src/config/examples/Tronxy/X1/Configuration.h

@@ -843,15 +843,16 @@
 #endif
 
 /**
- * Filament Runout Sensor
+ * Filament Runout Sensors
- * A mechanical or opto endstop is used to check for the presence of filament.
+ * Mechanical or opto endstops are used to check for the presence of filament.
  *
- * RAMPS-based boards use SERVO3_PIN.
+ * RAMPS-based boards use SERVO3_PIN for the first runout sensor.
- * For other boards you may need to define FIL_RUNOUT_PIN.
+ * For other boards you may need to define FIL_RUNOUT_PIN, FIL_RUNOUT2_PIN, etc.
- * By default the firmware assumes HIGH = has filament, LOW = ran out
+ * By default the firmware assumes HIGH=FILAMENT PRESENT.
  */
 //#define FILAMENT_RUNOUT_SENSOR
 #if ENABLED(FILAMENT_RUNOUT_SENSOR)
+  #define NUM_RUNOUT_SENSORS   1     // Number of sensors, up to one per extruder. Define a FIL_RUNOUT#_PIN for each.
   #define FIL_RUNOUT_INVERTING false // set to true to invert the logic of the sensor.
   #define FIL_RUNOUT_PULLUP          // Use internal pullup for filament runout pins.
   //#define FIL_RUNOUT_PULLDOWN      // Use internal pulldown for filament runout pins.

Marlin/src/config/examples/Tronxy/X5S/Configuration.h

@@ -852,15 +852,16 @@
 #endif
 
 /**
- * Filament Runout Sensor
+ * Filament Runout Sensors
- * A mechanical or opto endstop is used to check for the presence of filament.
+ * Mechanical or opto endstops are used to check for the presence of filament.
  *
- * RAMPS-based boards use SERVO3_PIN.
+ * RAMPS-based boards use SERVO3_PIN for the first runout sensor.
- * For other boards you may need to define FIL_RUNOUT_PIN.
+ * For other boards you may need to define FIL_RUNOUT_PIN, FIL_RUNOUT2_PIN, etc.
- * By default the firmware assumes HIGH = has filament, LOW = ran out
+ * By default the firmware assumes HIGH=FILAMENT PRESENT.
  */
 //#define FILAMENT_RUNOUT_SENSOR
 #if ENABLED(FILAMENT_RUNOUT_SENSOR)
+  #define NUM_RUNOUT_SENSORS   1     // Number of sensors, up to one per extruder. Define a FIL_RUNOUT#_PIN for each.
   #define FIL_RUNOUT_INVERTING false // set to true to invert the logic of the sensor.
   #define FIL_RUNOUT_PULLUP          // Use internal pullup for filament runout pins.
   //#define FIL_RUNOUT_PULLDOWN      // Use internal pulldown for filament runout pins.

Marlin/src/config/examples/Tronxy/XY100/Configuration.h

@@ -863,15 +863,16 @@
 #endif
 
 /**
- * Filament Runout Sensor
+ * Filament Runout Sensors
- * A mechanical or opto endstop is used to check for the presence of filament.
+ * Mechanical or opto endstops are used to check for the presence of filament.
  *
- * RAMPS-based boards use SERVO3_PIN.
+ * RAMPS-based boards use SERVO3_PIN for the first runout sensor.
- * For other boards you may need to define FIL_RUNOUT_PIN.
+ * For other boards you may need to define FIL_RUNOUT_PIN, FIL_RUNOUT2_PIN, etc.
- * By default the firmware assumes HIGH = has filament, LOW = ran out
+ * By default the firmware assumes HIGH=FILAMENT PRESENT.
  */
 //#define FILAMENT_RUNOUT_SENSOR
 #if ENABLED(FILAMENT_RUNOUT_SENSOR)
+  #define NUM_RUNOUT_SENSORS   1     // Number of sensors, up to one per extruder. Define a FIL_RUNOUT#_PIN for each.
   #define FIL_RUNOUT_INVERTING false // set to true to invert the logic of the sensor.
   #define FIL_RUNOUT_PULLUP          // Use internal pullup for filament runout pins.
   //#define FIL_RUNOUT_PULLDOWN      // Use internal pulldown for filament runout pins.

Marlin/src/config/examples/UltiMachine/Archim2/Configuration.h

@@ -843,15 +843,16 @@
 #endif
 
 /**
- * Filament Runout Sensor
+ * Filament Runout Sensors
- * A mechanical or opto endstop is used to check for the presence of filament.
+ * Mechanical or opto endstops are used to check for the presence of filament.
  *
- * RAMPS-based boards use SERVO3_PIN.
+ * RAMPS-based boards use SERVO3_PIN for the first runout sensor.
- * For other boards you may need to define FIL_RUNOUT_PIN.
+ * For other boards you may need to define FIL_RUNOUT_PIN, FIL_RUNOUT2_PIN, etc.
- * By default the firmware assumes HIGH = has filament, LOW = ran out
+ * By default the firmware assumes HIGH=FILAMENT PRESENT.
  */
 //#define FILAMENT_RUNOUT_SENSOR
 #if ENABLED(FILAMENT_RUNOUT_SENSOR)
+  #define NUM_RUNOUT_SENSORS   1     // Number of sensors, up to one per extruder. Define a FIL_RUNOUT#_PIN for each.
   #define FIL_RUNOUT_INVERTING false // set to true to invert the logic of the sensor.
   #define FIL_RUNOUT_PULLUP          // Use internal pullup for filament runout pins.
   //#define FIL_RUNOUT_PULLDOWN      // Use internal pulldown for filament runout pins.

Marlin/src/config/examples/Velleman/K8200/Configuration.h

@@ -882,15 +882,16 @@
 #endif
 
 /**
- * Filament Runout Sensor
+ * Filament Runout Sensors
- * A mechanical or opto endstop is used to check for the presence of filament.
+ * Mechanical or opto endstops are used to check for the presence of filament.
  *
- * RAMPS-based boards use SERVO3_PIN.
+ * RAMPS-based boards use SERVO3_PIN for the first runout sensor.
- * For other boards you may need to define FIL_RUNOUT_PIN.
+ * For other boards you may need to define FIL_RUNOUT_PIN, FIL_RUNOUT2_PIN, etc.
- * By default the firmware assumes HIGH = has filament, LOW = ran out
+ * By default the firmware assumes HIGH=FILAMENT PRESENT.
  */
 //#define FILAMENT_RUNOUT_SENSOR
 #if ENABLED(FILAMENT_RUNOUT_SENSOR)
+  #define NUM_RUNOUT_SENSORS   1     // Number of sensors, up to one per extruder. Define a FIL_RUNOUT#_PIN for each.
   #define FIL_RUNOUT_INVERTING false // set to true to invert the logic of the sensor.
   #define FIL_RUNOUT_PULLUP          // Use internal pullup for filament runout pins.
   //#define FIL_RUNOUT_PULLDOWN      // Use internal pulldown for filament runout pins.

Marlin/src/config/examples/Velleman/K8400/Configuration.h

@@ -852,15 +852,16 @@
 #endif
 
 /**
- * Filament Runout Sensor
+ * Filament Runout Sensors
- * A mechanical or opto endstop is used to check for the presence of filament.
+ * Mechanical or opto endstops are used to check for the presence of filament.
  *
- * RAMPS-based boards use SERVO3_PIN.
+ * RAMPS-based boards use SERVO3_PIN for the first runout sensor.
- * For other boards you may need to define FIL_RUNOUT_PIN.
+ * For other boards you may need to define FIL_RUNOUT_PIN, FIL_RUNOUT2_PIN, etc.
- * By default the firmware assumes HIGH = has filament, LOW = ran out
+ * By default the firmware assumes HIGH=FILAMENT PRESENT.
  */
 //#define FILAMENT_RUNOUT_SENSOR
 #if ENABLED(FILAMENT_RUNOUT_SENSOR)
+  #define NUM_RUNOUT_SENSORS   1     // Number of sensors, up to one per extruder. Define a FIL_RUNOUT#_PIN for each.
   #define FIL_RUNOUT_INVERTING false // set to true to invert the logic of the sensor.
   #define FIL_RUNOUT_PULLUP          // Use internal pullup for filament runout pins.
   //#define FIL_RUNOUT_PULLDOWN      // Use internal pulldown for filament runout pins.

Marlin/src/config/examples/Velleman/K8400/Dual-head/Configuration.h

@@ -852,15 +852,16 @@
 #endif
 
 /**
- * Filament Runout Sensor
+ * Filament Runout Sensors
- * A mechanical or opto endstop is used to check for the presence of filament.
+ * Mechanical or opto endstops are used to check for the presence of filament.
  *
- * RAMPS-based boards use SERVO3_PIN.
+ * RAMPS-based boards use SERVO3_PIN for the first runout sensor.
- * For other boards you may need to define FIL_RUNOUT_PIN.
+ * For other boards you may need to define FIL_RUNOUT_PIN, FIL_RUNOUT2_PIN, etc.
- * By default the firmware assumes HIGH = has filament, LOW = ran out
+ * By default the firmware assumes HIGH=FILAMENT PRESENT.
  */
 //#define FILAMENT_RUNOUT_SENSOR
 #if ENABLED(FILAMENT_RUNOUT_SENSOR)
+  #define NUM_RUNOUT_SENSORS   1     // Number of sensors, up to one per extruder. Define a FIL_RUNOUT#_PIN for each.
   #define FIL_RUNOUT_INVERTING false // set to true to invert the logic of the sensor.
   #define FIL_RUNOUT_PULLUP          // Use internal pullup for filament runout pins.
   //#define FIL_RUNOUT_PULLDOWN      // Use internal pulldown for filament runout pins.

Marlin/src/config/examples/Wanhao/Duplicator 6/Configuration.h

@@ -853,15 +853,16 @@
 #endif
 
 /**
- * Filament Runout Sensor
+ * Filament Runout Sensors
- * A mechanical or opto endstop is used to check for the presence of filament.
+ * Mechanical or opto endstops are used to check for the presence of filament.
  *
- * RAMPS-based boards use SERVO3_PIN.
+ * RAMPS-based boards use SERVO3_PIN for the first runout sensor.
- * For other boards you may need to define FIL_RUNOUT_PIN.
+ * For other boards you may need to define FIL_RUNOUT_PIN, FIL_RUNOUT2_PIN, etc.
- * By default the firmware assumes HIGH = has filament, LOW = ran out
+ * By default the firmware assumes HIGH=FILAMENT PRESENT.
  */
 //#define FILAMENT_RUNOUT_SENSOR
 #if ENABLED(FILAMENT_RUNOUT_SENSOR)
+  #define NUM_RUNOUT_SENSORS   1     // Number of sensors, up to one per extruder. Define a FIL_RUNOUT#_PIN for each.
   #define FIL_RUNOUT_INVERTING false // set to true to invert the logic of the sensor.
   #define FIL_RUNOUT_PULLUP          // Use internal pullup for filament runout pins.
   //#define FIL_RUNOUT_PULLDOWN      // Use internal pulldown for filament runout pins.

Marlin/src/config/examples/adafruit/ST7565/Configuration.h

@@ -852,15 +852,16 @@
 #endif
 
 /**
- * Filament Runout Sensor
+ * Filament Runout Sensors
- * A mechanical or opto endstop is used to check for the presence of filament.
+ * Mechanical or opto endstops are used to check for the presence of filament.
  *
- * RAMPS-based boards use SERVO3_PIN.
+ * RAMPS-based boards use SERVO3_PIN for the first runout sensor.
- * For other boards you may need to define FIL_RUNOUT_PIN.
+ * For other boards you may need to define FIL_RUNOUT_PIN, FIL_RUNOUT2_PIN, etc.
- * By default the firmware assumes HIGH = has filament, LOW = ran out
+ * By default the firmware assumes HIGH=FILAMENT PRESENT.
  */
 //#define FILAMENT_RUNOUT_SENSOR
 #if ENABLED(FILAMENT_RUNOUT_SENSOR)
+  #define NUM_RUNOUT_SENSORS   1     // Number of sensors, up to one per extruder. Define a FIL_RUNOUT#_PIN for each.
   #define FIL_RUNOUT_INVERTING false // set to true to invert the logic of the sensor.
   #define FIL_RUNOUT_PULLUP          // Use internal pullup for filament runout pins.
   //#define FIL_RUNOUT_PULLDOWN      // Use internal pulldown for filament runout pins.

Marlin/src/config/examples/delta/FLSUN/auto_calibrate/Configuration.h

@@ -982,15 +982,16 @@
 #endif
 
 /**
- * Filament Runout Sensor
+ * Filament Runout Sensors
- * A mechanical or opto endstop is used to check for the presence of filament.
+ * Mechanical or opto endstops are used to check for the presence of filament.
  *
- * RAMPS-based boards use SERVO3_PIN.
+ * RAMPS-based boards use SERVO3_PIN for the first runout sensor.
- * For other boards you may need to define FIL_RUNOUT_PIN.
+ * For other boards you may need to define FIL_RUNOUT_PIN, FIL_RUNOUT2_PIN, etc.
- * By default the firmware assumes HIGH = has filament, LOW = ran out
+ * By default the firmware assumes HIGH=FILAMENT PRESENT.
  */
 //#define FILAMENT_RUNOUT_SENSOR
 #if ENABLED(FILAMENT_RUNOUT_SENSOR)
+  #define NUM_RUNOUT_SENSORS   1     // Number of sensors, up to one per extruder. Define a FIL_RUNOUT#_PIN for each.
   #define FIL_RUNOUT_INVERTING false // set to true to invert the logic of the sensor.
   #define FIL_RUNOUT_PULLUP          // Use internal pullup for filament runout pins.
   //#define FIL_RUNOUT_PULLDOWN      // Use internal pulldown for filament runout pins.

Marlin/src/config/examples/delta/FLSUN/kossel/Configuration.h

@@ -973,15 +973,16 @@
 #endif
 
 /**
- * Filament Runout Sensor
+ * Filament Runout Sensors
- * A mechanical or opto endstop is used to check for the presence of filament.
+ * Mechanical or opto endstops are used to check for the presence of filament.
  *
- * RAMPS-based boards use SERVO3_PIN.
+ * RAMPS-based boards use SERVO3_PIN for the first runout sensor.
- * For other boards you may need to define FIL_RUNOUT_PIN.
+ * For other boards you may need to define FIL_RUNOUT_PIN, FIL_RUNOUT2_PIN, etc.
- * By default the firmware assumes HIGH = has filament, LOW = ran out
+ * By default the firmware assumes HIGH=FILAMENT PRESENT.
  */
 //#define FILAMENT_RUNOUT_SENSOR
 #if ENABLED(FILAMENT_RUNOUT_SENSOR)
+  #define NUM_RUNOUT_SENSORS   1     // Number of sensors, up to one per extruder. Define a FIL_RUNOUT#_PIN for each.
   #define FIL_RUNOUT_INVERTING false // set to true to invert the logic of the sensor.
   #define FIL_RUNOUT_PULLUP          // Use internal pullup for filament runout pins.
   //#define FIL_RUNOUT_PULLDOWN      // Use internal pulldown for filament runout pins.

Marlin/src/config/examples/delta/FLSUN/kossel_mini/Configuration.h

@@ -982,15 +982,16 @@
 #endif
 
 /**
- * Filament Runout Sensor
+ * Filament Runout Sensors
- * A mechanical or opto endstop is used to check for the presence of filament.
+ * Mechanical or opto endstops are used to check for the presence of filament.
  *
- * RAMPS-based boards use SERVO3_PIN.
+ * RAMPS-based boards use SERVO3_PIN for the first runout sensor.
- * For other boards you may need to define FIL_RUNOUT_PIN.
+ * For other boards you may need to define FIL_RUNOUT_PIN, FIL_RUNOUT2_PIN, etc.
- * By default the firmware assumes HIGH = has filament, LOW = ran out
+ * By default the firmware assumes HIGH=FILAMENT PRESENT.
  */
 //#define FILAMENT_RUNOUT_SENSOR
 #if ENABLED(FILAMENT_RUNOUT_SENSOR)
+  #define NUM_RUNOUT_SENSORS   1     // Number of sensors, up to one per extruder. Define a FIL_RUNOUT#_PIN for each.
   #define FIL_RUNOUT_INVERTING false // set to true to invert the logic of the sensor.
   #define FIL_RUNOUT_PULLUP          // Use internal pullup for filament runout pins.
   //#define FIL_RUNOUT_PULLDOWN      // Use internal pulldown for filament runout pins.

Marlin/src/config/examples/delta/generic/Configuration.h

@@ -969,15 +969,16 @@
 #endif
 
 /**
- * Filament Runout Sensor
+ * Filament Runout Sensors
- * A mechanical or opto endstop is used to check for the presence of filament.
+ * Mechanical or opto endstops are used to check for the presence of filament.
  *
- * RAMPS-based boards use SERVO3_PIN.
+ * RAMPS-based boards use SERVO3_PIN for the first runout sensor.
- * For other boards you may need to define FIL_RUNOUT_PIN.
+ * For other boards you may need to define FIL_RUNOUT_PIN, FIL_RUNOUT2_PIN, etc.
- * By default the firmware assumes HIGH = has filament, LOW = ran out
+ * By default the firmware assumes HIGH=FILAMENT PRESENT.
  */
 //#define FILAMENT_RUNOUT_SENSOR
 #if ENABLED(FILAMENT_RUNOUT_SENSOR)
+  #define NUM_RUNOUT_SENSORS   1     // Number of sensors, up to one per extruder. Define a FIL_RUNOUT#_PIN for each.
   #define FIL_RUNOUT_INVERTING false // set to true to invert the logic of the sensor.
   #define FIL_RUNOUT_PULLUP          // Use internal pullup for filament runout pins.
   //#define FIL_RUNOUT_PULLDOWN      // Use internal pulldown for filament runout pins.

Marlin/src/config/examples/delta/kossel_mini/Configuration.h

@@ -972,15 +972,16 @@
 #endif
 
 /**
- * Filament Runout Sensor
+ * Filament Runout Sensors
- * A mechanical or opto endstop is used to check for the presence of filament.
+ * Mechanical or opto endstops are used to check for the presence of filament.
  *
- * RAMPS-based boards use SERVO3_PIN.
+ * RAMPS-based boards use SERVO3_PIN for the first runout sensor.
- * For other boards you may need to define FIL_RUNOUT_PIN.
+ * For other boards you may need to define FIL_RUNOUT_PIN, FIL_RUNOUT2_PIN, etc.
- * By default the firmware assumes HIGH = has filament, LOW = ran out
+ * By default the firmware assumes HIGH=FILAMENT PRESENT.
  */
 //#define FILAMENT_RUNOUT_SENSOR
 #if ENABLED(FILAMENT_RUNOUT_SENSOR)
+  #define NUM_RUNOUT_SENSORS   1     // Number of sensors, up to one per extruder. Define a FIL_RUNOUT#_PIN for each.
   #define FIL_RUNOUT_INVERTING false // set to true to invert the logic of the sensor.
   #define FIL_RUNOUT_PULLUP          // Use internal pullup for filament runout pins.
   //#define FIL_RUNOUT_PULLDOWN      // Use internal pulldown for filament runout pins.

Marlin/src/config/examples/delta/kossel_pro/Configuration.h

@@ -972,15 +972,16 @@
 #endif
 
 /**
- * Filament Runout Sensor
+ * Filament Runout Sensors
- * A mechanical or opto endstop is used to check for the presence of filament.
+ * Mechanical or opto endstops are used to check for the presence of filament.
  *
- * RAMPS-based boards use SERVO3_PIN.
+ * RAMPS-based boards use SERVO3_PIN for the first runout sensor.
- * For other boards you may need to define FIL_RUNOUT_PIN.
+ * For other boards you may need to define FIL_RUNOUT_PIN, FIL_RUNOUT2_PIN, etc.
- * By default the firmware assumes HIGH = has filament, LOW = ran out
+ * By default the firmware assumes HIGH=FILAMENT PRESENT.
  */
 //#define FILAMENT_RUNOUT_SENSOR
 #if ENABLED(FILAMENT_RUNOUT_SENSOR)
+  #define NUM_RUNOUT_SENSORS   1     // Number of sensors, up to one per extruder. Define a FIL_RUNOUT#_PIN for each.
   #define FIL_RUNOUT_INVERTING false // set to true to invert the logic of the sensor.
   #define FIL_RUNOUT_PULLUP          // Use internal pullup for filament runout pins.
   //#define FIL_RUNOUT_PULLDOWN      // Use internal pulldown for filament runout pins.

Marlin/src/config/examples/delta/kossel_xl/Configuration.h

@@ -981,15 +981,16 @@
 #endif
 
 /**
- * Filament Runout Sensor
+ * Filament Runout Sensors
- * A mechanical or opto endstop is used to check for the presence of filament.
+ * Mechanical or opto endstops are used to check for the presence of filament.
  *
- * RAMPS-based boards use SERVO3_PIN.
+ * RAMPS-based boards use SERVO3_PIN for the first runout sensor.
- * For other boards you may need to define FIL_RUNOUT_PIN.
+ * For other boards you may need to define FIL_RUNOUT_PIN, FIL_RUNOUT2_PIN, etc.
- * By default the firmware assumes HIGH = has filament, LOW = ran out
+ * By default the firmware assumes HIGH=FILAMENT PRESENT.
  */
 //#define FILAMENT_RUNOUT_SENSOR
 #if ENABLED(FILAMENT_RUNOUT_SENSOR)
+  #define NUM_RUNOUT_SENSORS   1     // Number of sensors, up to one per extruder. Define a FIL_RUNOUT#_PIN for each.
   #define FIL_RUNOUT_INVERTING false // set to true to invert the logic of the sensor.
   #define FIL_RUNOUT_PULLUP          // Use internal pullup for filament runout pins.
   //#define FIL_RUNOUT_PULLDOWN      // Use internal pulldown for filament runout pins.

Marlin/src/config/examples/gCreate/gMax1.5+/Configuration.h

@@ -866,15 +866,16 @@
 #endif
 
 /**
- * Filament Runout Sensor
+ * Filament Runout Sensors
- * A mechanical or opto endstop is used to check for the presence of filament.
+ * Mechanical or opto endstops are used to check for the presence of filament.
  *
- * RAMPS-based boards use SERVO3_PIN.
+ * RAMPS-based boards use SERVO3_PIN for the first runout sensor.
- * For other boards you may need to define FIL_RUNOUT_PIN.
+ * For other boards you may need to define FIL_RUNOUT_PIN, FIL_RUNOUT2_PIN, etc.
- * By default the firmware assumes HIGH = has filament, LOW = ran out
+ * By default the firmware assumes HIGH=FILAMENT PRESENT.
  */
 #define FILAMENT_RUNOUT_SENSOR
 #if ENABLED(FILAMENT_RUNOUT_SENSOR)
+  #define NUM_RUNOUT_SENSORS   1     // Number of sensors, up to one per extruder. Define a FIL_RUNOUT#_PIN for each.
   #define FIL_RUNOUT_INVERTING false // set to true to invert the logic of the sensor.
   #define FIL_RUNOUT_PULLUP          // Use internal pullup for filament runout pins.
   //#define FIL_RUNOUT_PULLDOWN      // Use internal pulldown for filament runout pins.

Marlin/src/config/examples/makibox/Configuration.h

@@ -855,15 +855,16 @@
 #endif
 
 /**
- * Filament Runout Sensor
+ * Filament Runout Sensors
- * A mechanical or opto endstop is used to check for the presence of filament.
+ * Mechanical or opto endstops are used to check for the presence of filament.
  *
- * RAMPS-based boards use SERVO3_PIN.
+ * RAMPS-based boards use SERVO3_PIN for the first runout sensor.
- * For other boards you may need to define FIL_RUNOUT_PIN.
+ * For other boards you may need to define FIL_RUNOUT_PIN, FIL_RUNOUT2_PIN, etc.
- * By default the firmware assumes HIGH = has filament, LOW = ran out
+ * By default the firmware assumes HIGH=FILAMENT PRESENT.
  */
 //#define FILAMENT_RUNOUT_SENSOR
 #if ENABLED(FILAMENT_RUNOUT_SENSOR)
+  #define NUM_RUNOUT_SENSORS   1     // Number of sensors, up to one per extruder. Define a FIL_RUNOUT#_PIN for each.
   #define FIL_RUNOUT_INVERTING false // set to true to invert the logic of the sensor.
   #define FIL_RUNOUT_PULLUP          // Use internal pullup for filament runout pins.
   //#define FIL_RUNOUT_PULLDOWN      // Use internal pulldown for filament runout pins.

Marlin/src/config/examples/stm32f103ret6/Configuration.h

@@ -853,15 +853,16 @@
 #endif
 
 /**
- * Filament Runout Sensor
+ * Filament Runout Sensors
- * A mechanical or opto endstop is used to check for the presence of filament.
+ * Mechanical or opto endstops are used to check for the presence of filament.
  *
- * RAMPS-based boards use SERVO3_PIN.
+ * RAMPS-based boards use SERVO3_PIN for the first runout sensor.
- * For other boards you may need to define FIL_RUNOUT_PIN.
+ * For other boards you may need to define FIL_RUNOUT_PIN, FIL_RUNOUT2_PIN, etc.
- * By default the firmware assumes HIGH = has filament, LOW = ran out
+ * By default the firmware assumes HIGH=FILAMENT PRESENT.
  */
 //#define FILAMENT_RUNOUT_SENSOR
 #if ENABLED(FILAMENT_RUNOUT_SENSOR)
+  #define NUM_RUNOUT_SENSORS   1     // Number of sensors, up to one per extruder. Define a FIL_RUNOUT#_PIN for each.
   #define FIL_RUNOUT_INVERTING false // set to true to invert the logic of the sensor.
   #define FIL_RUNOUT_PULLUP          // Use internal pullup for filament runout pins.
   //#define FIL_RUNOUT_PULLDOWN      // Use internal pulldown for filament runout pins.

Marlin/src/config/examples/tvrrug/Round2/Configuration.h

@@ -847,15 +847,16 @@
 #endif
 
 /**
- * Filament Runout Sensor
+ * Filament Runout Sensors
- * A mechanical or opto endstop is used to check for the presence of filament.
+ * Mechanical or opto endstops are used to check for the presence of filament.
  *
- * RAMPS-based boards use SERVO3_PIN.
+ * RAMPS-based boards use SERVO3_PIN for the first runout sensor.
- * For other boards you may need to define FIL_RUNOUT_PIN.
+ * For other boards you may need to define FIL_RUNOUT_PIN, FIL_RUNOUT2_PIN, etc.
- * By default the firmware assumes HIGH = has filament, LOW = ran out
+ * By default the firmware assumes HIGH=FILAMENT PRESENT.
  */
 //#define FILAMENT_RUNOUT_SENSOR
 #if ENABLED(FILAMENT_RUNOUT_SENSOR)
+  #define NUM_RUNOUT_SENSORS   1     // Number of sensors, up to one per extruder. Define a FIL_RUNOUT#_PIN for each.
   #define FIL_RUNOUT_INVERTING false // set to true to invert the logic of the sensor.
   #define FIL_RUNOUT_PULLUP          // Use internal pullup for filament runout pins.
   //#define FIL_RUNOUT_PULLDOWN      // Use internal pulldown for filament runout pins.

Marlin/src/config/examples/wt150/Configuration.h

@@ -857,15 +857,16 @@
 #endif
 
 /**
- * Filament Runout Sensor
+ * Filament Runout Sensors
- * A mechanical or opto endstop is used to check for the presence of filament.
+ * Mechanical or opto endstops are used to check for the presence of filament.
  *
- * RAMPS-based boards use SERVO3_PIN.
+ * RAMPS-based boards use SERVO3_PIN for the first runout sensor.
- * For other boards you may need to define FIL_RUNOUT_PIN.
+ * For other boards you may need to define FIL_RUNOUT_PIN, FIL_RUNOUT2_PIN, etc.
- * By default the firmware assumes HIGH = has filament, LOW = ran out
+ * By default the firmware assumes HIGH=FILAMENT PRESENT.
  */
 //#define FILAMENT_RUNOUT_SENSOR
 #if ENABLED(FILAMENT_RUNOUT_SENSOR)
+  #define NUM_RUNOUT_SENSORS   1     // Number of sensors, up to one per extruder. Define a FIL_RUNOUT#_PIN for each.
   #define FIL_RUNOUT_INVERTING false // set to true to invert the logic of the sensor.
   #define FIL_RUNOUT_PULLUP          // Use internal pullup for filament runout pins.
   //#define FIL_RUNOUT_PULLDOWN      // Use internal pulldown for filament runout pins.