Schneider Premium PLC P57 454 - Scan Time

[abdulqavi]

HI,

I am working on Schneider Premium PLC P57 454, how to check scan time?

Awaiting your answer's to my query..

Thanks

 

[Lare]

go to online -> hardware configuration -> double click PLC -> select animation

 

[abdulqavi]

Thank you

"Maximum Duration" in the table shows the total scan time of the program and it will in milliseconds (ms)?

As am beginner in PLC field, your corporation will highly appreciated.

 

[Lare]

there is three values, minimum, current and maximum.
You should look current. Current and maximum should be much less than watcdog time, else your PLC will go halt-mode. (Watchdog overrun)

PLC have 2 different scan modes. Cyclic (free wheeling) and periodic.
Cyclic processes program as fast as possible.

Periodic means that you can have something like 100ms period for program. Logic code can still have something like 20ms scan time, but before next program scan PLC waits 80ms (80+20=100ms)

Setting periodic/cyclic is maded at offline before program downloading. It is poperties of MAST-task.

 

[abdulqavi]

Thank you very much Lare

I need to have a constant or average value of scan time like (10ms), this current value keeps changing as per scanning of program.

Please find the attached screenshot.

Please advice.

 

[Lare]

10ms. You probably need then fast-section on Unity. Select fast-task and select from properties periodic/ 10ms. Do only needed program sections to fast section.


But IO is updated with fast scan only if you select fast-propeties on needed io-cards.

Where you need 10ms scan?

 

[abdulqavi]

Actually, the current and maximum time is exceeding with respect to watchdog time.. I want to minimize this.

is it advisable to change/increase watchdog time? if yes, please let me know the procedure to do the same.

your guidance is really working for me

Thanks