Omron PROFINET IO CJ1W-PRM21 Operation Manual page 128

Operating the network
Note
112
1 The Output Data state is PLC Mode Dependent.
If the PLC is in Program mode then the Output Data is marked as invalid.
If the PLC is in Monitor/Run mode then the Output Data is marked as valid.
2 The Output Data state is User Bit Controlled.
Bit 12 of Software switch 1, the Set output data valid bit, set the state of the
output data. If the bit is set to ON the Output Data is set to valid.
When the Output Data state is User Bit Controlled then it can be set or reset
from any place. From an HMI or SCADA system or another PLC. But most
logical is the PLC program. For instance a Function Block that supports
redundant IO Controllers need to use the User Bit Controlled way of operation.
For commissioning purposes also the IO Controller DTM can be used. In the
Diagnosis item, IO Controller Status sub item has the button Toggle User Bit
to set/reset the Output Data state.
When the Valid Output Data Handling is set to User Bit Controlled then
the Outputs of the IO Devices will only be controlled if the Output Data of
the IO Controller is valid. Input Data coming from the IO Devices is for-
warded to PLC memory if it is set to valid by the IO Device.
Figure 7.20: User Bit Controlled
Section 7-6