[Imported] How many sites under a communication channel are in comm. failure?

[sbeadle]

>>Message imported from previous forum - Category:ClearSCADA Software<<
User: Tanquen, originally posted: 2019-07-16 20:01:34 Id:472
Is there an existing OPC tag in ClearSCADA that can tell how many sites under a communication channel are in comm. failure.

[sbeadle · Accepted solution]

>>Responses imported from previous forum

Reply From User: Tanquen, posted: 2019-07-16 20:04:19
Something like this or is there a better way?

(* Setup the SQL data type for the query *)
TYPE
Point : INT;
END_TYPE

PROGRAM Outstation_Health_Query

(* Internal script tag linked to database OPC tag *)
VAR
Comm_Fail_Count AT %M(.Comm Fail Count) : INT;
END_VAR

(* Query the SQL database for the Full of each outstation *)
VAR
SQL_Query AT %S(SELECT Count(*) FROM CADVOUTSTATION WHERE ( "SourceName" = '~Config.Communication.Garvey Reservoir Radio Outstation Set' ) AND ( "QualityDesc" = 'Comm Failure' )) : RESULTSET OF Point;
END_VAR

(* Move the number of failed outstations returned by the query into the linked OPC tag *)
Comm_Fail_Count := SQL_Query.Value;

END_PROGRAM

Reply From User: BevanWeiss, posted: 2019-07-16 23:48:44
I'd recommend avoiding the use of QualityDesc if you can.
Filtering by a nice comparable 'number' is better than comparing strings.

There will be a Quality associated with that QualityDesc. I'd use that, and then have comments to indicate what the 'magic number' is for.

I'd also use NO CACHE, and configure the Comm_Fail_Count as AT %Q (since you never read the value of it). I'd also remove the TYPE definition. You don't need the TYPE defined, you can use a normal INT datatype in the SQL return definition.

Reply From User: Tanquen, posted: 2019-07-17 00:46:43
I'll give those options a try. Just wanted to make sure there was not some existing built-in tag.
Thanks.

Reply From User: adamwoodland, posted: 2019-07-17 23:08:34
Probably better to use State[Desc] rather than Quality[Desc]. Off the top of my head I think I check State

Reply From User: BevanWeiss, posted: 2019-07-19 09:12:29
[at]adamwoodland said:
Probably better to use State[Desc] rather than Quality[Desc]. Off the top of my head I think I check State
I don't believe there is an OPC tag for this.

But some of the State values