Commands; Appendix B: Control Panel Protocol - Sennheiser SDC 8200 AO System Manual

Appendix B: Control panel protocol

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Appendix B: Control panel protocol
The SDC 8200 conference and interpretation system supports a control
panel. The central unit sends a control command to the connected control
panel:
when a delegate or chairman unit is activated,
when a delegate or chairman unit is deactivated,
when a microphone goes into request mode,
when all active microphones are deactived simultaneously
(priority function).
The control panel sends a control command to the central unit:
when a delegate or chairman unit is to be activated,
when a delegate or chairman unit is to be deactivated,
when the control panel is to be reset (Reset).
The control panel must be connected to the central unit's COM 2 interface
(RS 232 connection). The settings for the communications port for the
control panel are:
Bits per second: 19,200
Data bits: 8
Parity: None
Stop bits: 1
Flow control: None

Commands

All commands sent by the central unit start with a "%" sign. The last char-
acter is a character which states the end of the transmission. Just before
the end-of-transmission character, there are four characters within the
command sent to the camera control which account for the CRC checksum.
STX "%"
Start of Transmis- Data of the com-
sion Character mand
(0x25 = "%")
The CRC checksum is in uppercase hexadecimal form while all other num-
bers are in decimal form.
data CRC
16 bit sum of the
ASCII characters
between STX and
CRC
ETX
End of Transmis-
sion Character
(0x0D)