BSI uses devices from Measurement Computing and Broadcast Tools for its automation interfaces.
Broadcast Tools makes and audio switcher that can be controlled by Simian. Look at their ACS 8.2 Plus.
Measurement computing makes a USB device that will connect between the satellite and the computer--the USB 1024LS. I prefer the usb-DIO 24/37, which is the same device except it has a 37 pin "D" connector for the input, rather than the little tiny screw-in terminal board on the other device
Measurement computing also has a series of relay boards that can be driven by the USB devices through Simian..
1. To have the satellite talk to Simian, you use the 1024-LS and its 24 different lines or "trigger" inputs in Simian parlance. You set Simian up to respond to the device on the "hardware" tab. Under the "async" tab you can edit the triggers and even set up different trigger sets depending on daypart. A trigger can simply start the next event, as in getting into a stop-set, or can start a macro, e.g. run a liner, and turn on an audio channel, such as getting out of a stopset and returning to the network. Read the manual.
2. Either the broadcast tools device or the relay board and external circuits can be used to switch audio channels on/off. We have an Auditronics 2500 console in main control, and use the relay board to turn channels on and off remotely--a feature of this console (you have to leave the faders up, of course,). Our "long form" programming from ABC/Citadel comes in one pot, ABC news another pot and the evening Delilah show a third pot. The newer R55E has the same feature, as do other consoles. In Simian this is simply a relay command, after you use the hardware tab to tell Simian which device you are using.