Sanyo VCC-MD500 - Manual (Page 7)

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[1] Communications Format
The communication unit is a 4 (min)-24 (max) byte
packet.
・Communications Speed:
2400, 4800, 9600, 19200, 38400
9600 bps
(DEFAULT MD800 – 500)
* MD400 and MD300 cannot connect at 38400bps.
DEFAULT is 19200bps.
・Data Length: 8 bit
・Start Bit: 1 bit
・Stop Bit: 1 bit
・Parity: None
・Flow Control: None
Packet Format ⁃
Header Message
0
Message
1
Message
2
Checksum Terminator
(0xFF)
Header Format ⁃
Bit 7
(MSB)
Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 0
(LSB)
Bit 1
1 0/1 0/1 0 0 0 0 0
・Bit 0-2: Fixed [0] *Reserved bit: Camera address
(0-7)
・Bit 3: Fixed [0] *Reserved bit: During broadcast
transmissions
・Bit 4: Fixed [0]
・Bit 5: During query commands [0], during settings
command [1]
・Bit 6: During settings/query [0], during response to
query [1]
Terminator Format ⁃
Bit 7
(MSB)
Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 0
(LSB)
Bit 1
1 1 1 1 1 1 1 1
・Bit 0-7: Fixed [1]
Message Format ⁃
Bit 7
(MSB)
Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 0
(LSB)
Bit 1
0 0/1 0/1 0/1 0/1 0/1 0/1 0/1
・Bit 0-6:Refer to the various commands (0-127)
・ Bit 7: Fixed [0]
Checksum Format ⁃
Bit 7
(MSB)
Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 0
(LSB)
Bit 1
0 0/1 0/1 0/1 0/1 0/1 0/1 0/1
・Bit 0-6: Take the value that sets the lower 7 bits of
the values added from the header to the
checksum to 0.
・Bit 7: Fixed [0]
Response Command Format ⁃
Bit 7
(MSB)
Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 0
(LSB)
Bit 1
1 1 1 1 0/1 0/1 0/1 0/1
・ Bit 0-3: ACK(Ah) / NACK(Bh) / ERR(Ch)
・ Bit 4-7: Fixed [1]
・ ACK: This is the response when the process of the
received command is correctly completed after
receiving the data in the correct format.
・ NACK: This is the response when data is received in an
incorrect format.
・ ERR: Although the data is received in the correct format,
this is the response when the process regarding
the received command is incorrect or cannot be
conducted.
Communications Protocol