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Network Feeds and Triggers

C

Charlie

Guest
Being UK-based, I'm not too familiar with how you US chaps take network feeds from the various shows available. Obviously I know it's by satellite but what are the technical details regarding network breaks, re-joins and such ? I assume the satellite hardware used offers some contact closures which are then connected to the automation system/switcher/desk. Are sub-audible tones used at all?

If somebody could confirm/clarify or perhaps point me to a site that does, I'd be grateful.
 
It depends on the network. The one with which I'm most familiar at the moment is NPR, and nowadays its programming arrives over a system called "Content Depot," which includes both live satellite feeds and satellite-based file transfers. Most of the live shows provide contact closures, though many of them (like the flagship newsmagazines "All Things Considered" and "Morning Edition") are tightly timed and can be automated based on timing without even using the contact closures.

The shows that arrive as file transfers simply go into the automation system once they arrive in the Content Depot storage receiver, and are then played out as files from the local automation.

I believe there are still some smaller networks out there using subaudible tones. The last major networks to use audible tones switched away from those systems (the Mutual network's "bwee-doop," most memorably) within the last decade or so.
 
The networks vary quite a bit.

For example, many NPR programs are hard-timed.
:00:00, "All Things Considered" hour introduction
:01:00, join news.
:06:00, leave news. :30 local break.
:06:30, Join "All Things Considered"
:19:00, begin 01:30 local break
... And so on

Beyond that, yes contact closures are provided by the receiver. They are sometimes generated by detecting 25/35 Hz subaudible tones, but it seems more common with today's digital systems to have a separate, low bandwidth channel to send closures. My understanding is that the Citadel XDS receiver does this. The network sends down a binary code "CX4" (example) and the receiver software maps this to "close switch on Relay 1, Pin 4."

--- while I was writing, Scott Fybush replied ---
The last major networks to use audible tones switched away from those systems (the Mutual network's "bwee-doop," most memorably) within the last decade or so.
Click to expand...
CNN radio included audible tones up until last year. I don't know that the tones were actually used by automation anywhere, but I distinctly remember hearing an audible tone after the sixty second avail at the end of the 3 minute CNN newscast.
 
The current generation of satellite receivers (the Wegener I-Pump and the XDS receiver) use relay closures. Most popular broadcast automation systems interface with devices such as the Broadcast Tools ACS 8.2 or the USB device made by measurement computing to detect these relay closures and thus get in and out of the network.

The Broadcast Tools device includes an audio switcher. Some automation programs use the sound card to mix or switch audio. We use another measurement computing device (relay panel driven by the computer) to turn mixers on and off on our consoles (R55E and older Auditronics 2500 series).

Also, the XDS receiver allows the ability to program the receiver to take different feeds (off the same satellite transponder) & re-program the relay closures to be consistent from one show to another. Very helpful for news-talk formats.
 
XDS is unique with a feature not touted. Satellite dies, internet rules. When the receiver dies it takes the internet feed. Discovered by accident.

Being non commercial we have one station that uses netcue (normally to record commercials) mute commercials.

Broadcast Tools is the industry standard, unless the automation has a built in switcher. (arrakis uses their own).

The connection to the computer is by rs232 and uses a usb input nowadays. obviously audio flows from the BT to the airchain and the computer to the BT. (Commercials or underwriting).

A few networks still use 25 and 35 hz tones which fire mueller decoders. These provide a hard output to the automation or BT. EWTN and IRN/USA still use this. fairly reliable but if the provider doesn't filter tones it can fire the automation at odd times.

Simian has a site that offers lots of info that is FREE. You have to register for the forums but it is free. http://www.bsiusa.com
 
Thanks for the replies - I've now got a better idea of how it's all done :)
 
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