Section 2 Compoway/F Communications Protocol; Data Formats; Command Frame - Omron KM50 Communications Manual

Section 2 CompoWay/F Communications Protocol

2. 1 Data Formats

In this manual, hexadecimal numbers are indicated by "hex" placed after the number. All other numbers
indicate ASCII characters. The numbers below the various parts of the frame are the number of bytes.

■ Command Frame

Node No.
STX
1 2
STX
Node No.
Sub-address
SID (service ID)
Command text
ETX
BCC
2-2
Text
Sub-address SID
0 0 0
2 1
BCC calculation range
This code (02 hex) indicates the beginning of a communications frame.
Always place this code in the first byte.
If the STX is received during data reception, reception will be started over
from where the STX is received.
• The node number indicates the destination of the frame.
• For the KM50-C/-E, specify the communications unit number.
• Either a number from 00 to 99 or "XX" (uppercase) can be set for the node
number.
• "XX" specifies broadcasting. Responses are not returned for broadcast
command frames.
• Responses are also not returned if any other node numbers are specified.
This is not used by the KM50-C/-E. Always set it to 00.
This is not used by the KM50-C/-E. Always set it to 00.
This is the command text. Refer to 2.2 Structure of Command Text for details.
This code (03 hex) indicates the end of a communications frame.
This is the block check character.
The BCC is found by taking the exclusive OR of the bytes from the node
number through the ETX.
Command text
ETX
BCC
1 1