Beside the audio also IO information can be transmitted from the encoder to decoder. For that the encoder needs some hardware inputs and the decoder must have one or more relays.
The following devices can be used as encoder with input capabilities:
Exstreamer500 and Exstreamer1000 (both have 4 inputs), Annuncicom1000 (8 inputs)
The following decoding devices have relays, in () is the number of available relays:
Exstreamer110 (1), Exstreamer120 (1), Exstreamer500 (4), Exstreamer1000 (4), Annuncicom1000 (8)
There are two solutions existing,
A - using the Instreamer firmware to Streaming Client firmware
B - using STL firmware on both sites
Using the Instreamer firmware to Streaming Client firmware
In the newer Instreamer firmwares (for encoder) is a configuration item available called "Send Contact Closure Information". When this is enabled the encoder will add the local input state information to the RTP header. In the decoder with Streaming Client firmware set in the web configuration under "Advanced Settings" -> "I/O" -> "Control Output x" = "Remote". With this setup the decoder will read the IO information from the RTP hearder and switches his local relay(s) according to the input state on the encoder.
Using STL firmware on both sites
Enable in the web setup under "CONFIGURATION" -> "Streaming" the feature "Keep-Alive Period" (set it to "0/Passive" on one site and set any timer, e.g. 100 ms, on the other site). Additionally set in the configuration under "IO and Control" -> "Relay x Mode" = "ON while remote Input x ON". When e.g. two Exstreamer500 are used, then relays can be switched on both sites, on the encoder and on the decoder.