Sennheiser SDC 8200 system manual Appendix a Camera control protocol, 120, Syntax of the commands

Appendix A: Camera control protocol

Appendix A: Camera control protocol

The SDC 8200 conference and interpretation system supports camera con- trol. The central unit sends a control command to the connected camera control:

ywhen a delegate or chairman unit is activated,

ywhen a delegate or chairman unit is deactivated,

ywhen all active microphones are deactived one after the other,

ywhen all active microphones are deactived simultaneously (priority function),

yevery 5 seconds for synchronization.

These commands are evaluated by the camera control which then auto- matically aims the camera at a speaker and adjusts the focus.

The camera control must be connected to the SDC 8200 CU central unit’s COM 2 interface (RS 232 connection). The settings for the communications port for camera control are:

Bits per second: 19,200

Data bits: 8

Parity: None

Stop bits: 1

Flow control: None

The syntax of the commands

All commands sent by the SDC 8200 CU central unit start with a “%” sign. The last character 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 “%”	data	CRC	ETX
Start of Transmis-	Data of the com-	16 bit sum of the	End of Transmis-
sion Character	mand	ASCII characters	sion Character
(0x25 = “%”)		between STX and	(0x0D)
		CRC

The CRC checksum is in uppercase hexadecimal form while all other num- bers are in decimal form.

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