The distinction between CHPIDs in the IODF and channels in HCM becomes very important for OPPP machines. Each IODF processor has its own set of CHPIDs. However, the OPPP machine has only one set of physical channels.
Usually each CHPID is mapped to a channel with the same number. However this is not necessary because some OPPP machines support the ability to map CHPIDs with different numbers to the same channel or to map CHPIDs to channels beyond channel FF.
When you create or re-number CHPIDs in an OPPP processor, a CHPID mapping is used to determine what channel the CHPID should be mapped to. Each processor can have a different CHPID mapping. The default CHPID mapping is one-to-one between CHPID numbers and channel numbers.
To edit the CHPID mapping for an OPPP processor, edit the processor and click CHPID Mapping in the Processor dialog. This opens the CHPID <> Channel Mapping dialog.
The listbox on the left lists all possible CHPID numbers (00- FF) and the channel numbers to which they map. The listbox on the right lists all possible channel numbers (00-1FF) and the CHPID numbers to which they map.
To change the mapping for a range of CHPID numbers, select the range in the left listbox and select the first channel number in the right listbox. Click Map to map the selected range of CHPID numbers to as many of channel numbers starting with the selected channel number.
If any of the target channel numbers is already mapped, the previous mapping is discarded. The previous CHPID numbers must be re-mapped before you can close this dialog (unless you press Cancel.)
After changing the CHPID mapping, any existing CHPIDs are remapped as appropriate.