Control requirements of a C300 are estimated in PUs, using a PU estimation spreadsheet similar to those used for C200 and ACE. The definition of a PU (see Section 1.4) does not change with the introduction of C300, because the PU definition is platform independent. C300 PU specifications are provided for the same set of typical module types (e.g. Small Analog Data Acquisition CM, Regulatory Control CM, Device Control CM, etc.) as already documented for C200 and ACE.
PU specifications are not provided for Series C IO Modules and PM IO Modules, because the IO Module execution for these IO types is not part of CEE. Processing load attributed to the execution of Series C IO
Modules and PM IO Modules is accounted for in the IO component of C300 CPU usage.