Omron CJ1W-PNT21, Инструкции по эксплуатации

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2 Nomenclature and Installation
2-14
CJ-series PROFINET IO Controller Unit Operation Manual for NJ-series CPU Unit (W511)
In case a connection fails, MRP Ring Redundancy ensures communication to all devices through
the alternative path.
The PROFINET IO Controller redundancy feature ensures a seamless change-over of the active
CPU and IO Controller to the standby CPU and IO Controller in case of malfunction.
Both the active and the standby IO Controller exchange data with all IO Devices in the network.
However, only the active IO Controller is in control of the outputs of the IO Devices.
The I/O data sent from the IO Controller to the IO Device and vice versa includes data state informa-
tion. This data-state information is used to signal to the receiving side that the IO Data is valid or
invalid. In case of invalid the receiving side will discard the data.
For IO Controller redundancy, the PROFINET IO Device must be capable of handling relations to
multiple IO Controllers. It is up to the IO Device to handle the situation where both IO Controllers
signal that the output data is valid. Normally the first IO Controller that signalled that the output data
is valid will be in control of the outputs of the IO Device. OMRON can therefore only guarantee
proper IO Controller redundancy operation if implemented with GRT1-PNT IO Devices.
In case of malfunction of the active IO Controller the user program will transfer control to the standby
Controller system. To avoid momentary changes in output data during this control change the Data
Hold parameter of each IO Device should be set sufficiently high for the standby IO Controller to
take over seamlessly. The appropriate Data Hold value should be determined experimentally.
2-3-2 PROFINET IO Controller redundancy