Intercom Interface for New Fiber Modules

How would I be able to interface with the new intercom system in the fiber modules. I would like to connect a clear com cs-702 with 5 Ursa broadcast cameras with the fiber modules. How would I accomplish this?

There is a DB 25 pin connector on the back, that you can adapt to 2W or 4W for Clearcom or RTS. Pin outs should be in the manual.

Hi, guys. I need to do the same thing. Hoping you can help.

So I've seen the pinout for the DB-25 connector you mention, but I'm confused as to how I interface that with our basic 2-wire RTS intercom system, as there are three cameras and three converters.

It looks like the intercom interface on the Fiber Converters is 4-wire, so I would assume that I need a 2-wire/4-wire interface (something like an RTS SSA-324?) to begin with. At that point, do I just need to connect that interface to one of the converters and ATEM magic will take care of the rest or do I need to somehow interface all three of those DB25 connectors with the RTS interface? If it's the latter, how do I do that? Do I need another piece of gear to simulate a four-wire system?

Any help would be greatly appreciated. Thanks!
Mark

[Gary Adams]

Hello. The DB-25 connector on the back of the Studio Fiber converter takes +0 dBu balanced audio in and out. This may be easily connected to any intercom 4 Wire interface. If you have multiple cameras and area also using one of our Talkback Converter or Talkback enabled ATEMS (2/4ME or TVS HD/4K/Pro Switchers), you would only need to connect to one of the Fiber Converters and the Production channel will be connected to the other cameras via our Talkback system. Without our Talkback system you would need a separate 4 Wire interface for each camera.

Regards, Gary

Thanks for your reply, Gary.

So the 2-wire/4-wire interface that's been recommended in a couple other posts in this forum is the RTS SSA-324 (I would include a link but this forum doesn't allow that ). The terminal block on the back of that device has terminals for "4-Wire In Hi", "4-Wire In Lo", "4-Wire Out Hi" and "4-Wire Out Lo". The DB-25 breakout on the Fiber Converter has pins for "IN+", "IN-", "OUT+", "OUT-" and "GND" (times two channels). Can you provide some guidance as to which pins go to which terminals? Does "Hi" mean "+" and does "Lo" mean "-"? What about the ground?

And once we get that figured out, there's still the fact that we're trying to interface three camera chains with this 2-wire intercom system. So do we just cram three wires into each of the terminals on the 4-wire interface or do we need a different interface that accommodates multiple devices? Would some type of splitter help?

Bottom line-- It seems like there's a significant lack of information online on how to integrate third-party comms (and tally) with these camera chains. Am I missing something? Can you point me to some documentation? Does Blackmagic have any partners who are familiar with doing what we need to do that might consult on this project? Does anyone make an interface box/cable that makes all of this any easier?

Again, your help is most appreciated!
Mark

[Gary Adams]

Hello Mark. All these are good questions. Your first questions are about the connections. So It's balanced audio. You would connect the + to high and - to low. Ground is usually shield and only needs to be connected at one end. There are numerous 4 wire interfaces so there is no common connection method. I have seen terminal strips, RJ-45 connectors, XLR connectors, RCA connectors. Everything would be custom. And I don't want to say it's just audio.

If you are not using the ATEM Talkback system, then you would need a separate 4 wire interface for each camera. You can't just wire them all up with the same interface. If you are using our Talkback system, then you only need to wire one and our Talkback system will connect all the cameras. Our Talkback infrastructure is implemented in the Talkback Converter, ATEM 2ME, 4ME, and Television Studio HD/Pro HD/4K switchers. If you have one of those then they will all be connected.

I'm sorry we don't have much in the way of documentation. This would be different for each setup. I would recommend help from one of our resellers who do system integration.

Regards, Gary

Understood. Thanks again, Gary.

If you are not using the ATEM Talkback system, then you would need a separate 4 wire interface for each camera. You can't just wire them all up with the same interface. If you are using our Talkback system, then you only need to wire one and our Talkback system will connect all the cameras. Our Talkback infrastructure is implemented in the Talkback Converter, ATEM 2ME, 4ME, and Television Studio HD/Pro HD/4K switchers. If you have one of those then they will all be connected.

You could technically get away with ONE 2/4-wire interface by bridging together the "4-wire In" on the fiber converter (aka cram all 3 wires into one terminal block) - this would essentially be a simple passive split of the audio signal, giving you comm send to all the cameras. For the other direction, the "4-wire out" of each camera could cram into the "4-wire in" on the SSA324, essentially doing a simple analog combine. As long as all camera ops don't speak at once (and most of the time they shouldn't be speaking at all right), this should work. Further, if all you really need is to get direction TO your camera ops (and don't care to have them speak at all), you could use a simple intercom line "dryer" such as this or this to achieve that without shelling out $$ for the SSA324/424.

Gary, could you elaborate on how having a Talkback Converter in the mix (no pun intended?) would be helpful in this case?

you can cold split.. but you will get dampening because of that.. Meaning you will loose volume..

And the intercoms are already suffering from low levels intercom. So i would recommend to add a Headphone amplifier or something in between to address this issue at the basestation side..

Got it. Thanks. We're just going to go with outboard comms/tally for this project.

I wish BMD would really step up and play with the big boys with regard to third-party integration, etc. I love some of the innovations in their products, but as long as they try to lock customers into their ecosystem like this, they'll never be a viable alternative to Sony/Ikegami/GV.

I wouldn't be too hard on BM in this case, 4-wire intercom is standard in most broadcast trucks and control rooms, 2-wire mostly used nowadays in corporate AV and smaller flypacks. While it's true most Sony/Ike/GV CCUs have support for both 4-wire and 2-wire, there are still many that have 4-wire support only.

I also want to add that IP based intercom is the future and RTS, Clearcom and Riedel are all making significant investments and headway in that direction. Since the BM fiber converters are already using IP to transport the video and audio, I see it quite possible for support for these modern IP based intercom solutions to be enabled via firmware.

Yep. But 2-wire isn't going away any time soon-- especially not for corp AV and flypack applications, like you mentioned. Those market segments should be a huge target for these cameras and, accordingly, they should have a simple method to integrate 2-wire comms, just like all the other guys do. I feel the cart is clearly before the horse here, in this respect.

I have the BM talkback unit and 4 of the SMPTE fiber converters. We have the 3G fiber LC I/O modules on the back connected to the Talkback Converter. So it seems that all we need to interface with a Clear Com MS702 is a DB25 4 wire cable, or do we need to get that RTS unit that converts 2 wire to 4 wire first.

Then once it's connected to one fiber unit, then it will be transferred via the Talkback Converter over LC fiber?

Thanks,

Cody Fay

Hello,

Does anyone have the wiring pin out between the RTS SA 324 and the BMD DB25 connector on the BMD Fiber converter?

I have the BM talkback unit and 4 of the SMPTE fiber converters. We have the 3G fiber LC I/O modules on the back connected to the Talkback Converter. So it seems that all we need to interface with a Clear Com MS702 is a DB25 4 wire cable, or do we need to get that RTS unit that converts 2 wire to 4 wire first.

Then once it's connected to one fiber unit, then it will be transferred via the Talkback Converter over LC fiber?

Thanks,

Cody Fay

Correct, You need to go 2 Wire to 4 wire first. Then when you have 4 wire ( Audio in and seperate audio out) you can add them to the Talkback converter.
From there it will carry the intercom trough the fiber.

[Gary Adams]

Hello Robert. Here is the connection information for the SSA-324. It may not look formatted right as it was copied out of a table. If it is not clear, I can put it a different way. Regards, Gary

Assuming you get 4w into the Base Station what is the result, is the 4w mixed with a channel of BM Talkback or does it replace it?

Edit: It looks like the cam operator gets to decide if she wants SDI or DB25 or both, how would the Atem operator choose. Is the 4w audio in to the DB25 then embedded in the SDI?

Within the BM universe what does the engineer ,or anyone else, use for intercom?