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Beginning with version 2.1 of the module firmware it is possible for all protocol stacks to extend the possible process data size using RPC (Remote Procedere Call) transport. This feature allows significantly increasing the size of process data beyond the boundaries of the cyclic channel (73 Byte). However, process data using the RPC transport come with a significant cut in performance.
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For EtherNet/IP the maximum data size is 505 Byte O->T and 509 Byte T-->O.
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Even if the update cycle of the process data is larger because of the RPC transport, the typically cycle time per communication stack can still be achieved. The update cycle and the cycle time are independet from each other. |
The update cycle for process data mapped to RPC depends on the amount of data required to update. Following table shows typical values where the amount of data is mapped to both communication directions (input data and output data) and all data is required to be updated in one cycle. The time required can reach 310 ms, see table below.
used module size per direction | average update cycle time |
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Octet string 1434 Byte | 310 ms |
Octet string 1024 Byte | 230 ms |
Octet string 512 Byte | 125 ms |
Octet string 256 Byte | 70 ms |
Octet string 128 Byte | 40 ms |
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