Studer D424, Инструкция по эксплуатации и обслуживанию

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D424 MO Recorder
E9/2 Appendix
SW V 1.6/V 2.6 Date printed: 06.03.02
9.1.3 Hardware Layer
• EIA RS422A
• Data rate 38.4 kBaud
• Full duplex communication
• Bit-serial asynchronous data transmission
• Data format:
1 start bit (logic “ 0” = SPACE)
8 data bits
1 parity bit (odd, number of “ 1” in D0...D7 and parity is odd)
1 stop bit (logic “ 1” = MARK)
LSB MSB
start
bit
D0 D1 D2 D3 D4 D5 D6 D7 parity
stop
bit
Connector: D-type, 9 pin female
D424 Pin Controlling device
Frame ground 1 Frame ground
Transmit A 2 Receive A
Receive B 3 Transmit B
Receive common 4 Transmit common
+24 V 5 -
Transmit common 6 Receive common
Transmit B 7 Receive B
Receive A 8 Transmit A
Frame ground 9 Frame ground
Logic “0” (SPACE) if signal B < A, logic “1” (MARK) if signal B > A
9.1.4 Messages
The structure of a command or a response message is as follows:
Byte 1 Byte 2 Byte 3 ... Byte n+2 Byte n+3
CMD1 N CMD2 DATA 1 ... DATA n CHKS
Byte 1 Command byte 1 (CMD 1)
The upper 4 bits of byte 1 indicate the command group and the communi-
cation direction.
From controller to D424:
0: System control command
2: Transport command
4: Preset/select command
6: Data request
From D424 to controller:
1: System control response (for type 0/2/4 commands)
7: Data response
Data count (N)
The lower 4 bits of byte 1 is the number of data bytes between CMD 2 and
CHKS (0...15).