Thanks for your reply. There are two possibilities for inputs.
1. Our existing setup (the homemade one that I'd like to modify) runs from the printer port of the MediaLab computer to a circuit box of some kind. There are 4 outputs from the circuit box that are plugged into digital inputs on the back of the Coulbourn port (V19-02). With our old software, the Coulbourn port was connected to our old physio data collection computer via a parallel port cable.
2. With our new system, the Coulbourn port is connected to a DataQ DI-720 Data Acquisition Module for WinDAQ Pro software, which then connects to our new physio data collection computer via USB. The connection from the Coulbourn port is made with a 37-pin D connector. There are two possible 37-pin connection inputs, one on the left side and one on the right side of the DI-720. This is straight from the DI-720 Manual:
DI 720 Series instruments can accept 32 high-level or preconditioned analog inputs in single-ended configuration or 16 high-level or preconditioned analog inputs in a differential configuration. High-level inputs are typically low impedance, no-conditioning required signals in the range of +/- 1.25 to +/- 10 volts full scale. Single-ended inputs are configured by connecting one signal lead to the desired channel and the other signal lead to analog ground (AGD).
(Me again). There are two channels (pins) on the right side input of the DI 720, R.Start/Stop and Evnt, which looks like they are designated for remote event triggers.
So to answer your question, it looks like there are two input options-one on the Coulbourn port and one on the DI-720. One question I have is whether it makes more sense to send the TTL from MediaLab to the Coulbourn port or to the DI-720. I realize this is a question for the Coulbourn/DataQ people, I'm still waiting on a reply from them. If what I've said makes enough sense that you can send assembly/wiring instructions, that would be great.
Thanks so much for your prompt assistance.