393
Appendix C
C-mode (Host Link) Command Master
The C-mode (Host Link) command master protocol provides communications sequences using C-mode com-
mand codes for a PLC (CS/CJ Series) host (master).
This protocol enables any C-mode command to be sent from a Serial Communications Unit/Board installed in
a CS/CJ-series PLC to a CS/CJ-series or C-series (see note) CPU Unit that is connected via RS-232C or RS-
422A/485.
Note C-series PLCs refer to the C200H, C200HS, C200HX/HG/HE(-Z), C120, C500, C500F, C1000HF,
CQM1, CPM1, CPM1A, CPM2A, CPM2C, SRM1, CQM1H, C1000H, and C2000H.
Note 1. Multiple-frame commands and multiple-frame responses are not supported.
2. Slave-initiated operations from the slave CPU Unit to the PLC master cannot be used.
Command and Response Formats
Note In the following diagrams “hex” indicates hexadecimal values. Values in quotation marks, such as “00”
indicate ASCII characters.
• Command Frame
• Response Frame
Serial Communications Board/Unit
C-mode command
Response
CS/CJ-series PLC
Serial Communications Board/Unit
Response
C-mode command
CS/CJ-series PLC CS/CJ-series PLC
CS/CJ-series PL
CS/CJ-series
PLC
PMCR
(260)
CS/CJ-series
PLC
PMCR
(260)
"@"
40 hex
Host Link
unit number
(X10
1
)(X10
0
)
CR
0D hex
"*"
2A hex
FCS
Tex t
Command code
2 bytes1 byte2 bytes2 bytes1 byte
0D hex
"*"
2A hex
CR
2 bytes
1 byte
FCS
Tex tEnd code
(X16
1
)(X16
0
)
2 bytes2 bytes
Command code
Host Link
unit number
(X10
1
)(X10
0
)
2 bytes
"@"
40 hex
1 byte