Ok thank you, appreciate the reply. I'll give it a shot!

I'm currently running a Duet and Duex5, and trying to control some external pumps and solenoids. I would like to trigger the solenoid using a gpio, but I have read the documentation and it's as clear as mud to me. I don't need high current, just a simple on and off for switching a MOSFET through gcode. I have no hotends and no fans, i'm using the Duet+Duex for controlling fluid dispensing on the E3D toolchanger.

So far I have tested:

1. Turning on and off existing fans I/Os with:
   M106 P7 S1.0. ; Turns on Fan7(according the PCB label)
   I have also set the fan voltage jumper to both 5V and 12V with no detectable voltage

2. M307 P27 I-1. ;Disable fan 7? Not sure
   M42 P27 S1.0 ;Turn on what was Fan7 output to high?

I also tried using the Duex GPIO pins which is my preferred method, but I honestly find the pin documentation sheet to be unreadable:
https://duet3d.dozuki.com/Wiki/Duet_2_Pinout_table.
What am I missing? Is there an example I can go off of that someone else had done for triggering something similar?

Board: Duet WiFi 1.02 or later + DueX5
Firmware: RepRapFirmware for Duet 2 WiFi/Ethernet 2.05.1 (2020-02-09b1)
Duet WiFi Server Version: 1.23