RS-232C

2. Software specifications

(1) External interface specifications

Communication

Asynchronous, full duplex

system

 

 

 

Baud rate

1200, 2400, 4800, 9600 or 19200 bps

 

 

Bit length

8 bits or 7 bits

 

 

Stop bit

1 bit or 2 bits

 

 

Parity

None, odd or even

 

 

<Notes>

O The factory settings are 9600 bps, 7 bits, 1 stop bit and odd parity.

O The unit’s receive buffer has a capacity of 127 bytes.

(2) Transmitting format (PC 5 unit)

$ Data format

[STX]

[discrimination]

[:]

[data]

[ETX]

02H

XX XX XX

3AH

XX

.....

XX

03H

 

20H<XX<7FH

(XX = hexadecimal character code)

Odiscrimination:

Command identifier (3 bytes)

O : : Code serving as a delimiter between the command and data

O data : The data code is added as and when required.

1.A send command always starts with STX (character code 02H).

“discrimination” which follows the command is the command identifier. If necessary, “data” is added after the colon (:). The command is ended with ETX (character code 03H).

2.When STX is re-sent before ETX is sent, the unit’s internal receive buffer is cleared (all the data received so far is destroyed), the re-sent STX is placed at the head, and the new data is processed.

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