Hi Omni,
@Hazen_Babcock is right that if for example the DAQ goes high and at the same time the “Device” goes low, then the “device” will have to be able to sink all the current from DAQ and this might destroy both as the DAQ might not be able to source this much current and the “device” might not be able to sink it.
A simple solution would be to either add a couple of resistors in series to reduce the current to below what they can source/sink or (since they will only be outputs) use a small signal diode (1N4148) in series, before the inputs of your 74LS86 XOR gate.
Something like this would work, I think.
Don’t forget to tie the unused inputs of the chip to ground or 5V to prevent them from floating and adding noise.