Omron CJ1W-PNT21 Operation Manual page 149

The device model is shown in the following graph:
/i
Number Description
1 Communication Unit
2 I/O Module
3 Submodule
4 Channel
Provider/Consumer Model
The data exchange between IO Controller and the IO Devices is carried out based on the provider-consumer
model. The provider sends its data to the consumer without a request from the other device. The consumer
processes the data. The provider (as the consumer) is either the IO Controller or the IO Device.
The Input Output Provider Status (IOPS) indicates the status of the data source (valid or invalid) for each of the
modules as part of the data exchange message. This can be the Output data for the IO Controller and the Input
data for the IO Device. The provider status is either bad or good, implying the received data is either invalid or
valid for use. For example the Output data of the IO Controller is set to bad in case the PLC is in Program
mode.
The Input Output Consumer Status (IOCR) indicates the feedback on the provided data received before. This
status (Bad or Good) is indicated in the Input data for the IO Controller and the Output data for the IO Device.
As an example when considering the IO Controller Redundancy: an IO Device will only feedback to the active
IO Controller it has consumed its output (status Good). The standby IO Controller will get IOCR Bad status as
response.
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