Machine Control Laying off to DigiBeta

[TheAvidGuy]

I have a Mix Plus system on OSX with the Avid AV/XL Option running 5.1.3. Digitizing from a DigiBeta works fine. The Avid editor gives us a Digibeta with locked picture so we can lay down our finished audio for a 22 minute reality show. The Meridien Breakout Box, the Digi USD, and DigiBeta DVW-A500 all are getting black from the same black burst generator. The AES ins and outs of the DBeta are connected directly to the 888 AES ins and outs. Slave out on the USD is connected to the Slave in on the 888. I play the timeline and with the deck in E/E, the AES lights on the 888 light and the 4 audio meters light on the DBeta. I go into Machine Control from the transport and then arm all 4 tracks of the DBeta and all 4 tracks arm on the DBeta. I click the record button. When I hit the play button on the transport, the AES lights on the 888 stop and the digiBeta lights get no signal. Even the picture stops moving on the NTSC monitor. No sound even makes it to the speakers. If you set the transport back to Pro Tools, you can now hear the audio thru the speakers again. There are two different DVW-500 profiles in the Machine Control tab of the Peripherals setup. There is no DVW-A500 profile...who knows why? Originally we had no problems laying off to tape with the first DBeta, but it was swapped out for another issue. Now we are on the third DBeta and I still couldn't lay off. After trying every possible switch on the DBeta and different settings in the Pro Tools software I tried a wiring config that I cannot find documented anywhere in the Pro Tools setup guide, or Machine Control documentation. I pulled the blacburst cable off the Ref in on the DBeta. I then connected the Slave Out of the 888 to the Ref. In on the DBeta. Now the Deck slaves up and the audio lays down to tape. Can anyone shed some light to why this works, and where this might be documented?

[FajitaTone]

PT clock ref comes from incoming TC. Switch to Jam sync and you will be able to lay back.

[TheAvidGuy]

Where do I find the Jam Sync settings?

[Chief Technician]

As part of the session setup window, you should be able to specify jam sync (and after how many frames it should jam) or freewheel.