Blackmagic Forum

Hi,
I am trying to set up tally lights for my Ikegami chains and i run into a problem with the tally signals from BMD Gpi&Tally converter.
In the description pins 23 (gpi out1) and 24 (ground) should send current (V) when cam1 is active but my multimeter shows only zeros (DC mode).
The converter is connected to ATEM because i can hear when relays open/close when cams are switched.
I tried all the pins and none of them works.
Except GPI ins they all are sending 2,5V.

Can someone please describe how this should be wired?
Maybe i have a defective converter if there should be a current in the multimeter when testing pins 23 and 24?
Maybe i should include GPI ins (at this point it does not make sense to me) for some reason to get it to work?
Thanks in advance!

Which Ikegami basestation? You shouldn’t need voltage just contact closure. The voltage is typically provided by the cam basestation and the switcher/tally interface just closes the circuit. Going the other way the switcher/interface provides the voltage.

Good Luck

martinslog wrote:Hi,
I am trying to set up tally lights for my Ikegami chains and i run into a problem with the tally signals from BMD Gpi&Tally converter.
In the description pins 23 (gpi out1) and 24 (ground) should send current (V) when cam1 is active but my multimeter shows only zeros (DC mode).
The converter is connected to ATEM because i can hear when relays open/close when cams are switched.
I tried all the pins and none of them works.
Except GPI ins they all are sending 2,5V.

Can someone please describe how this should be wired?
Maybe i have a defective converter if there should be a current in the multimeter when testing pins 23 and 24?
Maybe i should include GPI ins (at this point it does not make sense to me) for some reason to get it to work?
Thanks in advance!

I wouldn't expect the tally outputs to generate a voltage, just to make or break a connection (i.e. contact closure) - effectively opening and closing a switch.

If you measure the resistance rather than the voltage (i.e. use a multimeter on Ohms not Volts setting) of the connection between Pins 23 and 24 do you see a change in resistance when you cut to and from Cam 1 ?

https://www.blackmagicdesign.com/uk/pro ... s/W-ATC-03
The details for the GPI and Tally interface state the outputs are contact closure - so that's what I'd expect them to do.

Contact Closure is the normal standard for tallies and GPI/GPOs - so this is to be expected. What does your Ikegami's camera CCU specify for tally inputs?

yes its normal rellays contact outputs ..

Thanks for the prompt replays.
I fixed my tallys and everything is working perfectly fine.
For some reason, I was expecting it would generate a current that triggers CCU but it works in the "close circuit" principle.
If someone tries to fix this for Sony/Panasonic DB25 plug then it should be patched like this:
Cam1 (BMD) Pin23 -> Pin11 (Sony CCU)
(BMD) Pin10 -> Pin12 (Sony CCU)

Cam2 (BMD) Pin22 -> Pin11 (Sony CCU)
(BMD) Pin9 -> Pin12 (Sony CCU)

etc.

That doesn’t seem correct. The basestation tally should use the same pins for every cam. Red tally is always red tally, using different pins on the basestation side would indicate a different groound, color, or communication channel.

It’s easy to run out of ground pins quickly, and terminating DB25s is a chore. We typically use terminal blocks to simplify and expedite (couple minutes versus a couple hours) the process.

Good Luck

Howard Roll wrote:That doesn’t seem correct. The basestation tally should use the same pins for every cam. Red tally is always red tally, using different pins on the basestation side would indicate a different groound, color, or communication channel.

It’s easy to run out of ground pins quickly, and terminating DB25s is a chore. We typically use terminal blocks to simplify and expedite (couple minutes versus a couple hours) the process.

Good Luck

The OP may have edited the post since you replied - but the current post does have consistent Sony CCU pin numbering for each camera - Pins 11 and 12 on each Sony CCU for red tallies/cues.

It's the BMD multi-way connector that has different pin numbers for different source numbers.

Yeah I was (mis)reading it in pairs, looks fine.

Good Luck