4 Remote I/O Master Communications
4-32
CJ-series DeviceNet Units Operation Manual for NJ-series CPU Unit(W497)
4-6
Example of User Program for Remote
I/O Communications
When user program are written for remote I/O communications, make sure it performs I/O processing
with a slave under the following conditions:
•
*_Mstr1IOCommSta
(I/O Data Communications Status) is changed to TRUE.
•
*_UnitErr
(Unit Error) is changed to FALSE.
Example: There is no jump and slave I/O is processed when the JMP(004) instruction input condition is
FALSE in the following instructions. There is a jump and slave I/O is not processed when the JMP(004)
instruction input condition is TRUE.
Precautions for Correct Use
Precautions for Correct Use
Even if there is a communications error with the slave, the slave input data is saved in the allo-
cated area.
To prevent operating errors, make a user program so that no slave I/O processing will occur
when
*_UnitErr
(Unit Error) is TRUE.
aaaa_Mstr1IOCommSta
(I/O Data Communications)
STEP1
STEP1:
Processing other than slave I/O
Slave I/O processing
aaaa_UnitErr
(Unit Error)
Summary of Contents for CJ1W-DRM21
Page 12: ...Manual Structure 10 CJ series DeviceNet Units Operation Manual for NJ series CPU Unit W497 ...
Page 42: ...Revision History 40 CJ series DeviceNet Units Operation Manual for NJ series CPU Unit W497 ...
Page 345: ...Index 1 CJ series DeviceNet Units Operation Manual for NJ series CPU Unit W497 I Index ...
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