System.tag.configure - modify single property

Ignition
1

Hello,
Can I get an example to modify a single property of a single tag?
(I have seen many examples which read the config, edit a single property, then write back the entire config. I do NOT want to do this, and I should NOT have to, judging by the documentation, though I might be wrong.)

Let’s say my tagpath is:
[default]my/analog/tag

and I want to modify ‘scaleMode’
from ‘Linear’
to ‘Off’

Thanks everyone.
-Rob W.

2

system.tag.writeBlocking(["[default]my/analog/tag.scaleMode"], ["Off"])?

3

If the tag configuration property doesn’t seem to respond properly to being written via writeBlocking, this is the way via system.tag.configure:

parent_path = '[default]my/analog'
tag_name = 'tag'
config_changes = {'name':tag_name, 'scaleMode':'Off'}
system.tag.configure(parent_path,[config_changes],'m')

The key things to note is that you have to always include the name in the config structure, as well as the property you want to change, so that the configure operation knows which tag to apply it to, and you have to specify the 'm' mode on the configure operation or your old tag could lose all other properties and values.

I’ve also found that system.tag.configure in merge mode cannot change the datatype of the property. If it was an integer, you can only set it to an integer. If it was a string, you can only set it to a string.

4

@PGriffith - This is what I probably SHOULD have done.

@justin.brzozoski - This is what I wanted to do.

As a point of note: the problem I was running into was that I was sending in the entire tag_path as <parent_path>, instead I should have been sending the parent path and then including the tag name within the config_changes item as shown above. (I think the documentation could use this exact example as an update.)

Thank you both for your help here!