Hi jhorsburgh,

A 'dry' contact is usually a voltage free output as in a relay contact. In many cases it can be replaced by an open collector transistor output. But care must be taken to ensure there is floating power to one of the devices as the 0volts are connected together.

If you are sure there is no danger in connecting the 0 volts then a open collector will drive the input. Selection of the transistor is dependant on the voltage used on the trigger input and the current drawn.

If you can show what you are connecting to and the voltage across the input we can help a bit more.

When using the relay have you used a back EMF diode across the relay coil?

BobP