marcinmrag

PanelView plus 1250 slow response on the HMI screen

9 posts in this topic

Hello everybody!

I have a strange issue with the HMI screen. Respone time is very slow. I set update tags rate to 0.05. Intresting is that the problem existing only sometimes. For example i start machine and when i see that the sreen is lagging. I reset HMI and than it start working ok. HMI is done i FactoryTalk Version 10. RAM memory usage is ok. Any idea why this is happened?

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Dude, slow that rate down, your updates are almost faster than the human eye can see a light strobe!
Do you really need 20 updates a second for display?
 

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To expand upon NevergoldMel's response, when you set the update rate too fast you are asking the HMI for more than it can deliver. It will queue up the pending requests until the queue is full and then discard subsequent requests. The act of queuing and discarding requests takes up time that could be better spent providing data. While it may seem counter-intuitive, slowing down the update rate can often result in better performance. If you really need fresh data samples twenty times per second, a PanelView HMI is probably the wrong tool for the task.

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To add to Mel and Mav's comments.  What type of processor are you communicating with?

In the case of a SLC or MLX, you'll want to include a service interrupt in the PLC program.  This allows for the program scan to be interrupted to allow for "other" devices to communicate with the PLC.

In the case of Compact or ControlLogix, you'll want to look at the settings for program scan versus overhead (communication with other devices). 

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@Twigums in FactoryTalk Studio, open a display, right-click on any white space within that display, and select "Display Settings" from the pop-up dialog box. In the lower left corner of the Settings box you'll see "Maximum Tag Update Rate".

When the display is open in a running HMI project, this field value sets the rate at which the display must attempt to update the tag(s) value(s) from the controller. Depending on the process, 1 second is usually sufficient.

The quicker the update rate, the more often the HMI will request the data be retrieved across the network, which can cause communication issues in other devices on that network.

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Thank you guru.  I am having a similar issue with a preview plus 600.  It is communicating rs232 to an slc 5/03 processor.  Sometimes it takes buttons up to 5 seconds to respond.  Sometimes they respond immediately.   Sometimes its like they buttons are being held down.  Update rate is set to maximum of 1 sec.  Any idea what could cause this?

 

To add to the information, it is a converted PB32 program from an old panelview 600.  All the objects communicate with the plc via hmi tags.

Edited by Twigums

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An RS232 connection can't handle very many tags at a 1-second interval.  Try changing the baud rate, but also consider making your screens less busy (fewer tags).

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@Twigums any way you add ethernet to your control cabinet?

Meanwhile, what @pturmel said ^.

Also, on the individual buttons, check their hold times and make sure they're not actually set to the max of 5 seconds.

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