I have a Channels table, with one column being the unit a channel is on. This can change, and is simply the name of the unit. I have another table in the driver that is the list of units, containing information like the serial number.
How can I trend the unit the channel is on?
Trending on strings does not work, nor does a dynamic discrete. There is no numeric representation (from the device) of the unit that is unique.
Any information is appreciated. Thanks.
Update with what the current trending looks like:
I mean that on the trend graph when trending=true is set, values like '1' or '2' is set, and you can't see the string values that were at the set time.
That looks like an issue to me, let's investigate via a collaboration task.
Adding a bit to the conversation
As mentioned, trending on strings should work if enabled in the driver:
- Putting trending on true for that read param (cf. Pieter)
- Add or change the Trend Type to "last"
At least based on the DM Docs. Ref: Trending | DataMiner Docs
As Michiel mentioned, trending a string is not ordered:
"In a trend graph, the strings will not be sorted or ordered. In the background these are numbered sequentially, so the first string that came in will be the lowest number, etc."
It can happen that the parameter is predefined as string in the MIB, whilst it really should be read out as a number (i.e. sorted/ordered). In that case a conversion inside the driver should be made. I had such a support use-case, where the squad worked around it by added an additional numerical column converting the original string column.
When you say 'Trending on Strings does not work', do you mean the driver does not allow it (so trending="true" has not been set on the read param)?