Scan Time

[Rich Ex]

Hi Friends ,
I seem to have an issue catching a single pulse . My Scada unit offers me a single pulse for a channel which I use to start a calculation . Thing is sometimes the program does not see the pulse . I am wondering if its the scan time of Rapid Scada … not sure how this works , is it like a PLC and takes time to work through all the Channels , I have 268 channels mostly calculated types with 32 real input types .

Thanks
Rich

[manjey73]

Where does the momentum come from? from the PLC ? it can appear in the period between the PLC requests – then the PLC program requires a delay of this pulse for the network variable. Or did you mean something else ?

[Rich Ex]

Hi , the single pulse comes from a sensor at the begging of a process line .
The single pulse only feeds the Scada unit which sends it to the Rapid Scada program.

Thanks
Rich

[Mikhail]

Hi,
You need to specify a pulse length and polling rate. And make sure that polling rate is fast enough to detect a pulse.

[Rich Ex]

Dear Mikhail
Can you give me some more detail please .
My pulse is less than 1 second , where do I set up the polling rate ?

Thank You
Rich

[Mikhail]

Hello,

where do I set up the polling rate ?

It’s in Communicator – Communication line – Line Parameters – Request Sequence
Could you post a part of communication line log here to analyze?

[Rich Ex]

Hi Mikhail

Screenshot
https://ibb.co/JjpsCfN

Can you explain the Timeout; Delay; Time ; Period; entries please .

thanks as always Rich

[Mikhail]

Hi,

Can you explain the Timeout; Delay; Time ; Period; entries please

Please read this. If something is not clear in the article, ask.

Could you post a part of communication line log here to analyze? It’s in Line Stats

[Rich Ex]

Hi MikHail ,
First , sorry I should have read the document before asking the question about polling times !

Right here’s the screen shot of the data
https://ibb.co/QCxrFJR

Thanks
Rich

[Mikhail]

Hi,

According to the log, your polling rate is about 1 second. It depends on network latency and controller speed.
So you need pulse length at least 2 seconds to detect it stable.

[Rich Ex]

Hi Mikhail ,

Yes I’m seeing that now .
Nothing on the line is happening quickly so I may need to just look at extending the pulse from the sensors ……

Thank you for your help .
Rich

[Rich Ex]

Hi Mikhail ,
About the scan times , my system is on a VM with a single CPU , this is showing high CPU usage 85-100% , could this be causing my delays ? …… what number of CPU’s would you recommend on a Windows VM machine , I have 9 Scada slaves each giving me 4 inputs .

Thanks
Rich

[Mikhail]

Hi,

Could you make a screenshot of the CPU usage by processes (Task Manager)?

[Rich Ex]

Hi Mikhail ,
Screens shots of the resource manager of the VM .
Sorted for highest CPU usage .

https://ibb.co/DDX21R3

and

https://ibb.co/mGxGjLj

Thanks

Rich

[Mikhail]

Hi,

What you can do to decrease CPU load:
1. Use RAM disk for C:\SCADA\ScadaComm\Log directory.
2. Add this log directory to antivirus exception.
3. Increase delays after request in request sequence or after line cycle.

[Author]

Posts