trends in panelview. do they go on forever?

[realolman]

I put a couple of "trends" in a PV+600 FactoryTalk ME ... they do pretty much exactly what I want them to do and they look good... I like them

Are these things gonna just keep working, or are they gonna quit somewhere down the road because they're memory is full or some such thing that I don't anticipate? Do they need to be reset or something?

from my experience, it seems there has to be a catch somewhere... It was too easy... this is the company that includes libraries of buttons that aren't buttons, but pictures of buttons , after all

thank you

 

[daba]

I believe they are both based on the same or similar RSTrendx activex control.

If the trend behaves the same as the Logix software trend, then it will capture as many data points as programmed, or until the memory is 80% "full".

 

[Ken Roach]

The data gets automatically deleted as it gets older.

How many data points depends on whether you are using the Data Log Model.

If you're not using the Data Log Model, then it's just however many points are onscreen at one time plus the "extra points" setting, which is usually 200 data points.

If you're using the Data Log Model you can set how many records to keep. Multiply by the interval at which you're logging the data, and you'll get an idea of how far back in time you can go.

I've never run one until it encountered a memory limit, so I can't say what it would do if you programmed very high numbers.

 

[daba]

....I've never run one until it encountered a memory limit, so I can't say what it would do if you programmed very high numbers.

As always, Ken has a better answer than me....

Anyway, I was called to a water authority pumping station out in the country, which channeled water for treatment from 7 outlying reservoirs.

Not the problem I was called for, but they also mentioned that their PanelView Plus was "running out of memory" regularly. I can't remember what happened when it did, perhaps they just restarted the application.

When I looked at the application, they had 7 trends, one for each reservoir, and were sampling the level tags every 10mS !!

I changed the sample rate on the tags to something more reasonable, I think I set it to 1 hour, but can't remember the details, and never heard back from them.

In summary, don't trend things at a high rate that don't change at a high rate.

 

[realolman]

All i did was size the thing and make the connections to the pens
I have three of these and they do not all display at one time
There are 3 or 4 pens on each and their purpose is so the operator
Can see the trends of objects moving by on a conveyor and set
Appropriate limits. I dont need a lot of history 10 objects per pen but i do need rates of up to 150 a minute. If it acted like a fifo and just lost what went off the graph
That would suit me fine
I dont want to have them run out of memory or
Something a week down the road. I have a lot of the application riding on these things
How can i make sure it doesnt quit on me?
Thank you