How does one read Scan Time GE 90-30?

rdrast · Apr 20, 2005

Question as above, the help in Proficy is less than useless, so I'm asking you guys

Is there any way to read the current scan time of the processor?

Unregistered · Apr 20, 2005

It should be on the taskbar, bottom left, along with logic equal/config equal

Unregistered · Apr 20, 2005

Sorry, I meant bottom right

rdrast · Apr 20, 2005

Thanks, but I mean programmatically. I desperately need to know the exact scan time every scan for my logic

Steve Bailey · Apr 20, 2005

It will take a little arithmetic in ladder logic, but use the Service Request (SVC_REQ) function with code 16 to read the elapsed time clock. Subtract the previous scan's value from the current reading.

rdrast · Apr 20, 2005

Thanks Steve. I appreciate the help ! (and can't wait to wash my hands of this project once and for all!)

_Spiff_ · Apr 21, 2005

Critical scantime

If you have a critical time situation. Why not use a timed interupt ? Putt all code that is critical in time in "special" subtoutine and set the triggered scantime.

Maybe not the solution for you or ?

rdrast · Apr 21, 2005

_Spiff_ said:
If you have a critical time situation. Why not use a timed interupt ? Putt all code that is critical in time in "special" subtoutine and set the triggered scantime.

Maybe not the solution for you or ?

That would be a wonderful idea, except that I am using a very high speed timed interrupt already, this CPU only supports one, and if I try to add the code I need to the ISR, even every 50'th call, the scan time goes to unacceptable levels, if not just faulting out on overrunning the interrupt time-slice.

How does one read Scan Time GE 90-30?

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