I tried out9 (LASER / VFD) and it worked.
; Configuration file for Duet 3 (firmware version 3)
; executed by the firmware on start-up
;
; generated by RepRapFirmware Configuration Tool v3.2.3 on Sat Mar 27 2021 21:56:24 GMT+0100 (Mitteleuropäische Normalzeit)
; General preferences
G90 ; send absolute coordinates...
M83 ; ...but relative extruder moves
M550 P"□□□" ; set printer name
; Drives
M569 P0.0 S1 ; physical drive 0.0 goes S1 forwards
M569 P0.1 S0 ; physical drive 0.1 goes S1 forwards S0 backwards
M569 P0.2 S0 ; physical drive 0.2 goes S1 forwards S0 backwards
M569 P0.5 S0 ; physical drive 0.5 goes S1 forwards S0 backwards
M584 X0.0 Y0.1 Z0.2 E0.5 ; set drive mapping
M350 X16 Y16 Z16 E16 I1 ; configure microstepping with interpolation
M92 X53.33 Y53.33 Z1636.66 E492.40 ; set steps per mm, orginal X80.00 Y80.00 Z400.00 E492.40
M566 X900.00 Y900.00 Z60.00 E120.00 ; set maximum instantaneous speed changes (mm/min)
M203 X6000.00 Y6000.00 Z120.00 E1200.00 ; set maximum speeds (mm/min)
M201 X500.00 Y500.00 Z20.00 E250.00 ; set accelerations (mm/s^2)
M906 X2800 Y2800 Z1600 E1200 I30 ; set motor currents (mA) and motor idle factor in per cent
M84 S60 ; Set idle timeout
; Axis Limits
M208 X0 Y0 Z0 S1 ; set axis minima
M208 X□□□ Y□□□ Z□□□ S0 ; set axis maxima
; Endstops
M574 X1 S1 P"io0.in" ; configure active-high endstop for low end on X via pin io0.in
M574 Y1 S1 P"io1.in" ; configure active-high endstop for low end on Y via pin io1.in
M574 Z1 S2 ; nachträglich eingefügt
; Z-Probe
M950 S0 C"io7.out" ; create servo pin 0 for BLTouch
M558 P9 C"io7.in" H5 F120 R0.5 T3000 ; set Z probe type to bltouch and the dive height + speeds, orninal M558 P9 C"^io7.in" H5 F120 T3000
; Try adding a small delay after deploying the probe. The simplest way is to use the R parameter in the M558 command. 0.1 sec should be sufficient.
;Remove the ^ in front of the pin name in the M558 command. It's only needed on Duet 2
G31 P500 X0 Y0 Z5 ; set Z probe trigger value, offset and trigger height, orgnial G31 P500 X0 Y0 Z2.5
M557 X0:530 Y0:300 S75:60 ; define mesh grid, orinal X10:190 Y10:190 S20
; Temp Heatbed
M308 S0 P"temp0" Y"thermistor" T100000 B4092 ; configure sensor 0 as thermistor (RS-Comp 769-1931, EPCOS NTC Thermistor, 100kΩ = 100000Ω) on pin temp0, orginal T100000 B4138
M950 H0 C"out0" T0 ; create bed heater output on out0 and map it to sensor 0
M307 H0 B1 S1.00 R0.5 D30.0 ; enable bang-bang mode for the bed heater and set PWM limit, orginal heating rate 2.429, dead time 5.50
; Zeitkonstante R mindestens doppelt so lang ist wie die Totzeit D
M140 H0 ; map heated bed to heater 0
M143 H0 S120 ; set temperature limit for heater 0 to 120C
; Temp Heater Hotend
M308 S1 P"temp1" Y"thermistor" T100000 B4138 ; configure sensor 1 as thermistor (ed3 Thermistor Cartridge with Semitec 104NT thermistor) on pin temp1
M950 H1 C"out1" T1 ; create nozzle heater output on out1 and map it to sensor 1
M307 H1 B0 S1.00 ; disable bang-bang mode for heater and set PWM limit
M307 H1 R2.664 C256.6 D8.87 V24.4 ; PID tune parameters for heater 1
M143 H1 S280 ; set temperature limit for heater 1 to 280C
; Fans
M950 F0 C"out7" Q500 ; create fan 0 on pin out7 and set its frequency, orninal M950 F0 C"out7" Q500
M106 P0 S1 H-1 ; set fan 1 value. Thermostatic control is turned off
M950 F1 C"out8" Q500 ; create fan 1 on pin out8 and set its frequency
M106 P1 S1 H1 T35 ; set fan 1 value. Thermostatic control is turned on
; Rotating Magnet Filament Monitor
M591 D0 P3 C"io2.in" S1 ; Duet3D rotating magnet sensor (P3) for extruder drive 5 (D0) is connected to io_2
; Sn 0 = disable filament monitoring (default), 1 = enable filament monitoring
; Servo 1
M950 S1 C"out9" ;Enabling Pin6 as GPIO Port 0 on the Expansion Slot for PWM @ 50Hz
;M42 P1 S0 ;Switching GPIO Port 0 Off
;M42 S0.8 S0.5 ; set 50% PWM on GPIO port 10
; Tools
M563 P0 D0 H1 F0 ; define tool 0
G10 P0 X0 Y0 Z0 ; set tool 0 axis offsets
G10 P0 R0 S0 ; set initial tool 0 active and standby temperatures to 0C
; Custom settings are not defined
; Miscellaneous
M501 ; load saved parameters from non-volatile memory
How can I connect a second servo MG995?