Omron SYSMAC CJ1W-SCU21-V1, Operation Manual

Page: 170 / 781

141
Host Link Function for Replacing Existing PLCs Section 4-6
1:1 Host Link
The frame format for a 1:1 Host Link is the same as that for the 1:N Host Link,
except the @, Host Link Unit No., and FCS are omitted.
• Command Format
• Response Format
4-6-2 Host Link-compatible Device Selection
Pre-Ver. 1.2 Units
In earlier models, when the host computer program used by the C-series Host
Link Unit was reused in a CS/CJ-series PLC, data could not be read normally
for some programs due to the differences in Host Link specifications.
Unit Ver. 1.2 or Later
When Serial Communications Units/Boards with Unit Ver. 1.2 or later are
used, however, the Board/Unit’s Host Link specifications can be switched
according to the CPU Unit or other Unit in which the host computer program is
to be reused.
The Host Link specifications change according to the Host Link compatible
device mode that is selected.
• When the following commands for reading I/O memory (RR, RL, RH, RC,
RD, RJ, and RG) are received, the number of data words in each
response frame that is returned to the host is different.
• When the command for reading the status of the CPU Unit (MS) is
received, the response format that is returned to the host according to the
FAL/FALS instruction execution status is different.
* CR
Terminator
Header code
R D
* CR
Header
code End code
R D 0 0
Terminator
Command Name
RR CIO AREA READ
RL LINK AREA READ
RH HR AREA READ
RC PV READ
RD DM AREA READ
RJ AR AREA READ
RG T/C STATUS READ
Command Name
MS PROCESSOR STATUS READ