SLC500 "S" bit/words monitoring

Can the "S" bits and words from the SLC-500 be monitored and written over, like for example the Hour, minute, seconds or the max scan time allowed using lets say a rsview32 or wonderware HMI?

Please comment previous experiences

Best Regards.

Yes... Since SLC/PLC 5 clocks are inaccurate, this is good way to sync them with the HMI.

Be very careful about the "written over" (by which I assume you meant writing from the HMI to the PLC). Ascertain the effect of any write before doing it. Most locations should be documented as to 'Read Only' status. Locations you can write to are genrally VERY POWERFUL.

Locations you can write to are genrally VERY POWERFUL.

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Amen. Anybody never seen "OTU S:5/0"in an SLC application? (Not one of mine of course, someone else's )

NOP said:

Amen. Anybody never seen "OTU S:5/0"in an SLC application? (Not one of mine of course, someone else's )

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Seen and done it. Been discussed here before. Is there a really good reason to fault out a processor if there is a math error? If the programmer did not miss something, then it shouldn't happen (or if someone does an edit later). But most processes don't really want to come to an abrupt halt - could ruin the product or worse and could be very dangerous. When I use the unlatch the math overflow, I put an alarm on the HMI and maybe some code to diagnose where this happened at. I haven't used other manufacturer's or even the contrologix, but from what I understand, a math overflow does not fault the processor.

math overflow fault





it is recommended in rockwell user maual