Data Point Not Updating

JoelHaggar

Hi,

We're onto out second Mango Installation and really happy with the software.

I just noticed that my data points don't seem to be updating. I have the data source (Modbus IP) to update every 10 seconds and the points are not changing and on the watch list I don't see the values highlight that indicates they are being updated.

Also, when every I make any change to the data source, even to ad a new point, on the watch list I get this message for all my data points: "Point value may not be reliable" and then can click on the refresh button for each one to get it back to normal. Any thoughts on these issues?

Thanks,
Joel.

JoelHaggar

One other thing I forgot to mention on the points not updating. If I go into the point edit page and click Restart I get a new valve but not any more after that.

Thanks,
Joel.

mlohbihler

Hi Joel,

What kind of logging are you using on the points? (Go to the point editing page to check it.) Do the timestamps update but not the values, or do the timestamps not update either?

JoelHaggar

I'm doing interval logging every minute. What is strange is that the list of data and time stamps shows the last time stamp from an hour ago and when the point valve was 272. But the chart below show up to date and shows when the valve changed to 858 an the chart shows that it's been at 858 for the last hour. The actual point has been increasing by 1 every second so Mango has not been getting the data.

I hope that made sense.

Thanks,
Joel.

Attachment: download link

mlohbihler

The history list and chart do not automatically refresh on this page, but the data in the top left does. In the screen capture it could be that the history list is not as current as the chart. Maybe sounds weird, but it's possible.

Also, note that what gets logged depends entirely on the logging settings. Conversely, what gets displayed on charts, history lists, and such uses memory cached data as well as logged values. So you may see much more detail on a point on the right-hand side of a chart than on the left.

For example, let's say your point updates every 10 seconds, has a cache size of 20, and the average for the period is logged every 5 minutes. A chart of the past hour will show 12 logged values for the hour and 20 values for the past 200 seconds. Sometimes the appearance of this chart - with much more detail recently - is odd to new users.

Again, depending upon settings you point values may not appear to update even though data sources are working properly. If the value has not changed you won't see the highlight on the watchlist for the value, but you should still see the timestamp highlight.

If you are not even seeing this, something is likely wrong with the data source. Are you seeing any alarms from it?

JoelHaggar

So there is definitely something strange going on. I created another identical data source and added one point under it to the PLC. and it has been updating perfectly. I then exported all my data points and did a find a replace to change the dataSourceXid on each point. I then deleted the old data source and imported all the data points under the new source. Now point is not updating.

There are about 240 data points, could this number be exceeding a limit?

Thanks,

Joel.

mlohbihler

Are you getting any alarms from the data source?

JoelHaggar

Originally I was not getting any alarms but i did some experimenting over the weekend and think i have at least identified the problem which seems to be with my PLC.

I recreated data the data source and imported the points in chunks at a time until I got an alarm or the source stopped updating. I narrowed it down to 2 data points and no mater what I did those two holding registers on the PLC seemed to screw things up. I changed to different registers on the PLC and it seems to be working fine now. I need to talk with the PLC manufacturer to see what they say.

Thanks for your help.

Joel.

mlohbihler

No problem. Thanks for following up.

ejanssen

I've had a similar problem. It seemed that if certain data points were enabled, everything from that device would read "Point value may not be reliable." The problem seemed to go away for the remaining data points if those "problem data points" were disabled.

After some experimenting, the problem went away entirely if the following boxes were selected in the data source menu:

“Use multiple write commands only”
“Contiguous batches only”
“Create slave monitor points”