My appologies if I am not explaining this right.
In a previous life when I used Cimplicity there was a setting in a tags logging parameters that defined an “ignore” value. When the logger encountered this value it ignored it which resulted in a null value in the database. Here is the scenario where I would find this usefull.
I have some devices that contain a value of 4000 when ‘calculating’ Other devices give me a different value. When these values are in the database it shows up on the chart and is misleading. It also has an impact when I have the chart auto scale the axis. If the database contained nulls then there would be a gap in the data and the scaling would be unaffected.
Can this be done now? Would this be a feature usefull for others?
The best I can come up with on the fly is suggesting that you just trigger the group on a condition != to that value, or if you have multiple tags that you can log or not log together, an action item that combines them.
I’m open to hearing whether this would be useful for others, though. As far as I know, this is the first time this has been requested.
If the only issue is extra data affecting your chart, you could put ‘value_column != 4000’ into the where clause everywhere you use that data in a chart.
All of the charts are user created using a pens table. If I understand you correctly,[quote]you could put ‘value_column != 4000’ into the where clause everywhere you use that data in a chart.[/quote] then would I put that statement in the where clause column of the pens table?
I’m trying to accomplish the same thing as TimE but when I put in ‘value_column != 1370’ into the Where Clause of the Easy Chart it doesn’t apply the clause.
Is there a list of variable names that can be used in the Where Clause field?
The variable names are the pen names on the chart. In this particular project I was using Version 7, easy chart and DB Pens. In the Where Clause I used the pen name: ‘SteelHeatPID != 4000’.
Thanks for the clarification but it doesn’t seem to be working for me. Might have to do with the fact that the data is coming from Tag Historian.