| Applies To: |
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| Summary: |
| After upgrading a v5.x/v6.x project to
Citect v7.x, all the Digital trend tags are trended with
a default scale of 0 - 32000. The work-around described in
KB article Q1337 does not seem
to work anymore. First note that Process Analyst is prefered and does not require any tricks to appropriately display digital trends. |
| Solution: |
| KB article Q1337 is inaccurate for Citect version 7.x. In version v7.x, Citect will use the scale of the last tag from 'TrendDigital' function. Therefore, ‘TrendDigital’ function and Trend tag definition should be modified as follow in order to assign a scale of -2 / +2 to a digital tag: Variable Tag Name : DIGITALSCALE Data Type : INT Unit Name : PLC_1 Address : V498 Raw Zero Scale : -2 Raw Full Scale : 2 Eng Zero Scale : -2 Eng Full Scale : 2 ‘TrendDigital’ function: INT FUNCTION TrendDigital(INT trendedvar, INT scalevar) /* scalevar is not used in the function */ RETURN trendedvar; /* function return, digital value */ END Trend Tag Name : TRENDTAG2 Sample Period : 2 |
| Keywords: |
| Trend, Scale, Digital, TrendDigital |
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