Data Format - Omron E5AN User Manual

CHAPTER 2 CompoWay/F COMMUNICATIONS PROCEDURES

2.1 Data Format

J Command frame
STX
1
STX
Node number
Sub-address
SID (service ID)
Command text
ETX
BCC
2--2
Unless otherwise indicated, numbers in this manual are expressed in hex-
adecimal. Values in double quotation marks, such as "00", are ASCII.
The number underneath each delimiter in a frame indicates the number
of bytes.
Node No. Sub-address
0 0
2 2
This code (02) indicates the beginning of the communications frame (text).
Always set this character in the first byte.
When STX is received again during reception, reception is carried out again from
the point where STX was received.
· This number specifies the transmission's destination.
· Specify the E5AN/EN/CN/GN's "Communications unit No.".
· BCD range "00" to "99" and "XX" can be set.
· Specify "XX" for a broadcast transmission. No response will be returned for broad-
cast transmissions.
· No responses will be returned from node Nos. set otherwise from the above.
This is not used on the E5AN/EN/CN/GN. Be sure to set the sub-address to "00".
This is not used on the E5AN/EN/CN/GN. Be sure to set the sub-address to "00".
Command text area. For details, see "2.2 Structure of Command Text."
This code (03) indicates the end of the text.
Block Check Character
The BCC result is found by calculating the exclusive OR of the bytes from the node
No. up to ETX.
Text
SID Command text
0
1
BCC calculation range
BCC
ETX
1 1