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APPENDIX B
Datavideo 232 Controller Command Set
Rev 3.1 July 29, 2006
Communication format:
Mode : no synchronization
Character Length : 1 start bit + 8 data bits + 1 parity bit + 1
stop bit
Data Rate : 38,400 BAUD
Parity : Odd parity
Command Format :
CMD1, CMD2, DATA bytes …., Checksum Byte
A command is made up of two address bytes, CMD1 and CMD2, a
variable number of data bytes, DATA, from 0 up to 15 and a checksum
byte. The checksum byte is the modulo 256 sum of all preceding bytes.
The most significant nibble of the CMD-1 byte represents the command
group. The least significant nibble represents the number of data bytes to
follow the CMD-2 byte.
Command Protocol:
CMD1, CMD2, DATA bytes …., Checksum Byte
Response: ACK
Other than the sense command, the unit will respond to all commands
affirmatively by sending the three-byte acknowledge (ACK) if the
checksum is valid. If the checksum is not valid, the unit will ignore the
command. Most commands will be responded to within 8msec. A Play
command from an Idle state will result in a response delay of up to
700msec. During this busy time, all commands will be ignored.
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