Omron E3X-DRT21 Operation Manual page 88

CompoWay/F Message Communications
Examples of End Codes
when Errors Occur
End Name
code
"13" BCC error
"14" Format error
"16" Sub-address error
"18" Frame length error The received frame length exceeds the
An end code is returned for each command block addressed to the local node.
A response is not returned if the characters in the response block are incom-
plete up to the ETX and BCC. The error detection priority indicates the order
by which errors are detected when multiple errors occur simultaneously.
Note 1. Noise interference may prevent a response being returned or cause an er-
ror response to occur. Always perform retry processing from the master if
noise interferes with responses.
2. The response time after sending a command can be as much as 6 s. If a
response has not been returned, wait 6 s before sending the next com-
mand.
The following examples show an end codes for commands that did not end
normally.
Example 1: Illegal Sub-address, No SID, and No Command Text
Command Block
STX Node number
02 Hex
Response Block
STX Node number
02 Hex
The end code is 16 (sub-address error). This end code is used because the
sub-address was received and the error detection priority of a sub-address
error is higher than a format error.
Example 2: No Command Text
Command Block
STX Node number
02 Hex
Response Block
STX Node number
02 Hex
Description
Received an incorrect BCC value.
• The command text contains characters
other than 0 to 9, or A to F. (This error
is not applicable to the echoback test.)
• No SID and command text.
• No command text.
• No MRC/SRC included in command
text.
• Received a block with an unsupported
sub-address.
• No sub-address, SID, and command
text.
• Sub-address is less than two charac-
ters, and there is no SID and command
text.
fixed number of bytes.
Sub-address ETX BCC
"0" "A" 03 Hex
Sub-address End code
"0" "A" "1" "6"
Sub-address SID ETX
"0" "0" "0" 03 Hex
Sub-address End code
"0" "0" "1" "4"
Section 4-5
Error
detection
priority
5
7
6
4
ETX BCC
03 Hex
BCC
ETX BCC
03 Hex
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