B&B Electronics 232OPSDA Manuale Utente Scaricare il pdf (Pagina 14)

12 Documentation Number 232OPSDA1397 Manual

B&B Electronics -- PO Box 1040 -- Ottawa, IL 61350

PH (815) 433-5100 -- FAX (815) 433-5105

Table 3.2 - Equivalent Values

Syntax

As mentioned earlier, the command string consists of four bytes.

The first byte is the start of message byte. The start of message

byte is always the “!” character. The second byte is the address byte.

This byte allows each unit to have a unique address (useful in RS-

485 networks). Since the 232OPSDA uses RS-232 communications,

this byte is the ASCII “0” (zero) character and cannot be changed.

The next two bytes are the command characters. These bytes are

used to specify which command will be executed by the module.

Some commands require a fifth byte, a data byte.

Command Syntax: !0___

|||||

||||Data Byte

|||2

command Byte

||1

Command Byte

| Address Byte

Start of Message Byte

ASCII Decimal Hexadecimal

! 33 21h

# 35 23h

0 48 30h

A 65 41h

D 68 44h

O 79 4Fh

R 82 52h

S 83 53h

NUL 0 0h

SOH 1 1h

STX 2 2h

ETX 3 3h

EOT 4 4h

ENQ 5 5h

ACK 6 6h

BEL 7 7h

1 2 ... 9 10 11 12 13 14 15 16 17 18 19 ... 27 28

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B&B Electronics 232OPSDA Manuale Utente Pagina 14