Misc. Ramblings

  • Thread starter Butler, Lawrence
  • Start date

Thread Starter

Butler, Lawrence

Questions first...

Is the intention that the PLC engine and the I/O engine are both RT processes (they pretty much have to be don't they??) If they are what
ramification does it have on adding new i/o online (same type as existing or different brand all together)?

On the shared memory I would imagine you would want to minimize the footprint, but then you would have to recompile to add more right?

How do we handle shutdown and restart of the PC as far as dynamic PLC values that need to be saved and restored such as the tuning parameters for a PID block? These can be changed frequently but should be maintained across shutdowns (at least in a well behaved PLC.) Disk writes could be costly every scan/solve cycle.

On the suggestion to have all the documentation (register or i/o wise, tag descriptors etc) included in the PLC itself, this would have to exist in a file on the PC anyway (in order to be maintained across PC shutdowns), and you would still be at the mercy of this file not disappearing....

Lawrence Butler

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