R
Hi All:
I have been following the threads on Non-Volatile Store and UPS Hack and have several questions/comments:
On restart after power failure what is the status of the outputs: OFF or LAST-STATE?
I suggest that they default to "OFF" with a PLC programmer option of "LAST-STATE"
Depending on the process or equipment that the LPLC is controlling the "best" or "safest" option may be either one.
Do we have a "1st Scan" Status Flag in the LPLC?
If we do not, I think we should include one. I find this type of flag very useful even in the PLCs that have battery backed data tables. It allows the PLC program to initialize correctly after a start/restart.
If we have both "1st Scan" and "Non-Volatile Store OK" flags it allows the PLC programmer to include logic for both a "warm" and "cold" restart.
Glad to see the progress that is occurring:
Ralph
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[email protected]
http://linuxplc.org/mailman/listinfo/linuxplc
I have been following the threads on Non-Volatile Store and UPS Hack and have several questions/comments:
On restart after power failure what is the status of the outputs: OFF or LAST-STATE?
I suggest that they default to "OFF" with a PLC programmer option of "LAST-STATE"
Depending on the process or equipment that the LPLC is controlling the "best" or "safest" option may be either one.
Do we have a "1st Scan" Status Flag in the LPLC?
If we do not, I think we should include one. I find this type of flag very useful even in the PLCs that have battery backed data tables. It allows the PLC program to initialize correctly after a start/restart.
If we have both "1st Scan" and "Non-Volatile Store OK" flags it allows the PLC programmer to include logic for both a "warm" and "cold" restart.
Glad to see the progress that is occurring:
Ralph
_______________________________________________
LinuxPLC mailing list
[email protected]
http://linuxplc.org/mailman/listinfo/linuxplc