47
4-3-3. Architecture of the serial transmission data
・
4-wire-transmission system.
・
Asynchronous bit-serial word-serial data transmission.
・
Data structure: 1 Start bit+8 Data bits+1 Parity bit+1 Stop bit
(Note 1) Odd Parity: The sum of the D0+D1+---D7 and Parity bit is an odd number.
(Note 2) Mark B>A; (Voltage on line B is higher than that on Line A)
Space A>B: (Voltage on line A is higher than that on Line B)
4-3-4. Command Format
Communication between control systems and this product uses the following command telegram
format:
CMD 1/Data count, CMD 2, and data checksum (CHECKSUM).
If Data count is zero, no data is transmitted. If it is not zero, the data corresponding to the existing
values are inserted between CMD2 and CHECKSUM.
CMD 1
Data
count
CMD 2
DATA 1
--------
DATA N
N=15max
CHECKSUM
・
CMD 1:
CMD 1 assigns the command to the following main function groups that serve to
define the function, and the transfer direction of the data words that follows.
CMD 1
Function
Transfer Direction
Controller---Recorder
0
System control
1
System control-Return message
2
Recorder control
4
Setup and selection control
8
Data request
7
Data request-Return message
Start
bit
D0
(LSB)
D1
D2
D3
D4
D5
D6
D7
(MSB)
Parity
(Odd)
Space
Mark
Bit
4-7
Bit
0-3