Searching for Technical details for GPI/Tally box

Hello,

I‘looking for one detail for GPI/Tally box. Does the input-pins really close to ground or is it a common pin, so that a closure to an other voltage, e.g. +5V could be made ?

[Gary Adams]

Hello Thomas. I don't have a schematic available but the inputs need to be pulled or shorted to one of the ground pins or to zero relative to our ground. I believe there is internal +5 V pull up. but a relay or common grounded circuit would work.

Regards, Gary

The idea was, to use the box for direct switching Datavideo TD1/2/3 tally units to a power supply. They have common ground for their both LED-chains. So It would be necessary to switch to power, when both colors have to be displayed. When switching to ground, only one color can be used. No problem, because the BM tally box suppout only on air (red) - or am I wrong ?