IMPORTANT: Read Me Before connecting anything to the GPICommander!




GPICommander uses “open-collector” inputs, which means that they CANNOT receive any current or voltage at any time. In order to trigger an action or status change on an input, it needs to be grounded. In other words, when pin 1 (input 1) of the DB25 connector is connected to pin 25 (the ground), it is considered as “ON”. When it is disconnected, it is considered as “OFF”.

So, if you want to connect a push-button, simply connect it between the desired input pin (1-24) and the ground (pin 25).

Some switchers and other devices might generate a 0 or 5V signal instead of a contact closure. This should NEVER be used on the GPICommander inputs as it will damage the components inside the unit and this is not covered by our 12 months warranty.

Instead, you will need to use a relay or any conversion device that will transform the 0-5V current into a contact closure that behaves like a switch.


The outputs are relay-based and each of them is independent, so you can connect different pieces of equipment to each output. There is no common ground as each output has two pins that are shorted together when ON.

There will be no current or voltage output on any of these pins as they are simple relays (each output has its own relay), so if you want to apply voltage to your input box (a box that supports voltage, but again, GPICommander inputs do NOT support voltage, they will break if you supply voltage to it, only do the following when using a different box that supports it), you could use a 9V battery and connect it positive to each of the relays (pins 1, 3, 5, 7, ...) and use the other one (2, 4, 6, 8, …) to go to each of the inputs of the “trigger box”. Then simply connect the negative of the battery to either the common of your trigger box or each of the inputs (other pin).


Contact us if you have questions

If you have any doubts or questions regarding the wiring of GPICommander, please contact us

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