Film-Tech Forum ARCHIVE: CP750 automation connector question

This is topic CP750 automation connector question in forum Digital Cinema Forum at Film-Tech Forum ARCHIVE.

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Posted by David Buckley (Member # 2600) on 06-14-2016, 04:00 AM:

Does anyone have any additional documentation or knowledge on the CP750 automation outputs on the DB25 connector?

The manual says pins 14 to 20 are tally LED outputs, but gives no real details. It further says that pin 13 is automation power, +5V at 50mA, and that pin 12 is common return for everything including power, so it must be a -ve. So my guess is that the tally outputs are intended to each drive a tally LED, and thus are 5V switched +ve feeds with about 20mA drive capability...?

Posted by Nguyen Jack (Member # 7530) on 06-15-2016, 01:35 AM:

Hi,
You can see it on page 67 & 68 of the document Dolby_CP750_Installation_Manual_v5.pdf

Posted by Carsten Kurz (Member # 5396) on 06-15-2016, 03:25 AM:

David - I have never seen a full electrical documentation on Dolbys automation connectors. Maybe there is a separate tech bulletin or something. You can dig up the DT6D manual from the warehouse and have a look at the DTS6D - Dolby interconnect schematics at the rear end of these docs to get an idea how inputs and outputs can be used, e.g. the DTS6D-CP65 or DTS6D-CP500 schematic.

- Carsten

Posted by Dave Macaulay (Member # 813) on 06-15-2016, 08:46 AM:

The v5 manual lists what the tally pins report. As to polarity - pretty easy to test with a meter and maybe a resistor. The tally pins will either give you a current source for a load to ground, or a ground sink for a load to the pin 15 +5V power.
You could try Dolby support if you don't want to experiment.