AVS-816 Protocol for Remote Control

This document outlines the serial data protocol required to control an AVS-816 Audio/Video switcher. This protocol can be used to control from 1 to 32 AVS-816s from a single computer. The hardware interconnect from the computer to the switcher may be either RS-232 or RS-422. An internal slide switch located on the AVS-816 mother board can set the unit to either standard. The hardware interconnect from one switcher to another uses the RS-485 signal interface on RJ-11 modular connectors. An internal DIP switch is used to assign a "unit identification" number (1 thru 32) to each switcher. Consult the AVS-816 manual for more details.

The serial control data takes the following form:

<STX> U V A <CR>

 

• STX = "Start of Text" (02h)
• U = The assigned unit identification number. ASCII "1-9,A-W" to accommodate up to 32 units. An ASCII "0" (30h) will switch all the units connected to the network.
• V = The video channel to be selected. ASCII "1-9,A-G" to accommodate 16 channels.
• A = The audio channel to be selected. ASCII "1-9,A-G" to accommodate 16 channels.
• CR = "Carriage Return" (0Dh)

The same data format is used to query an individual switcher. Simply transmit the appropriate unit identification number followed by an ASCII "0" (30h) in the Video (V) and Audio (A) slots. The response from the switcher will be in the same form,

<STX> U V A <CR>

If you desire to change only video or audio, you will still need to include the ASCII code for the channel not being changed. The resulting status of the switcher will be echoed back to the controlling computer.

Note 1: If all units are switched (U = 30h), there will be no echo.

Note 2: An Video/Audio selection made at the front panel will be transmitted to the remote control.

The AVS-816 also allows a remote operator to "lock" or "unlock" the switcher's front panel. This is done by substituting an ASCII "+" or "-" for the channel number normally inserted in the "V" or "A" slot.

 

• Lock Front Panel = ASCII "-" (2Dh)
• Unlock Front Panel = ASCII "+" (2Bh)

If you desire to keep a channel "Locked", you must update the locking command at least once every 90 seconds. If this is not done, the unit will automatically unlock itself.