Tag scripting problem

Ignition
1

Hello everyone,
I am having a really hard time figuring this one out …hope someone can shed some light…

  1. I have a named Query called “Alarm_Query” connected to an SQL DB that simply returns a SELECT string …the query works fine
  2. I have setup an alarm on each tag in a user-defined UDT (F726xx_ExtFltxx)
    tag_script
    tag_script1262×496 55.4 KB
  3. On the value change event of each tag I want to store the result string from the named query into the [.]…/AlmDspxxx tag of the UDT (the …/GP/G7261_FWTextxx is of type double and is the parameter I send in the query)
  4. I get the following error in the gateway
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Any help gratefully appreciated…

thanks and regards
Dominic

2

If you run system.db.runNamedQuery in the gateway scope (which all tag change events are) you need to provide the project name. Look at the second example of the documentation - system.db.runNamedQuery - Ignition User Manual 8.1 - Ignition Documentation

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3

That’s because tag change script execute in the gateway scope, so you need to use the gateway scope version of the runNamedQuery function. Its signature is system.db.runNamedQuery(project, path, parameters, [tx], [getKey])
You can see there that the first argument to the function needs to be a project, which is why it is looking for a project named Alarm_Query and not finding it.

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4

Also, this isn’t how you read or write to tags:
image

You need to use the system.tag.writeBlocking and system.tag.readBlocking functions.
https://docs.inductiveautomation.com/display/DOC81/system.tag

3 Likes
5

Hello Pascal,
I have updated the runNamedQuery function specifing the project and the gateway message error dispappeared.

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I now have a coerce problem…the namedQuery parameter is set to float8 (which I saw is double) and this is the datatype for the tag in the UDT that I use as the parameter…what am I doing wrong ??
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thanks and regards,
Dominic

6

That might be because of how you’re trying to update your tag’s value.

@PGriffith has already addressed this in the post just above.

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7

Actually its your system.db.runNamedQuery that is giving this problem. After "Alarm_Query" it’s exepecting a dictionary of parameters (hence why it says it’s trying to coerce it to a java.util.Map). You pass params like {'someNamedQueryParam1':'someValue'}. Right now you are just passing the string "[.]../GP/G_FWText1".

However what @pascal.fragnoud said will also be an issue as well.

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8

I’ll be honest: I didn’t even read the error message ;p

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