The decision was made long before I came along, at levels well above my pay grade. We use Opto products as a data acquisition system on oilfield equipment, and the daq and the process equipment being monitored is mounted on trucks. The company wanted to give the field operators the ability to troubleshoot, diagnose and fix problems with the DAQ without requiring PAC Control, PAC Manager, or any PLC/programming knowledge in general, so the ‘Points’ are uploaded to the string table in the scratchpad, and the strategy parses it on start-up to determine which memmap addresses it should be looking at for the data. All communication between the brains and the PC’s are done via the scratchpad.
We’re stuck supporting a dozen different groupings of I/O requirements, some consisting of several dozen process-plants-on-wheels identical on paper, and every one has it’s I/O cards in different rackslots. Some of them go months at a time without coming back to civilization.
Sadly, doing things ‘the right way’ is the more expensive option at this point, even if we could convince the operations folks that taking away their ability to move things at will was a good thing.