Emerson Exchange 365

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Reading calibration date

Hi,

 

Previously I was using a method described in BOL under "Accessing intelligent field device diagnostic data" to read the recommended action associated to some FF diagnostic conditions.

Now I am looking to get the last calibration date for an instrument using the same method but I am having difficulties "guessing" the right object index number.

As you can see in the picture, OI483 (recommended action) is correctly read for both instruments, but I think the object index number for the calibration date is incorrect.

The fact is, I do not know how these are calculated. In the fhx associated with the DD, the recommended action is defined as:

        PARAMETER NAME="FD_RECOMMEN_ACT" ITEMID=0x000203A7 SUBINDEX=0 TYPE=UINT32
        {
          VALUE { CV=0 }
        }

While the calibration date, which I would also like to read is:

        PARAMETER NAME="CAL_DATE_SENSOR" ITEMID=0x00020020 SUBINDEX=0 TYPE=DOUBLE
        {
          VALUE { CV=0.0 }
        }

Any guesses? Why does ITEMID=0x000203A7 correspond to OI483 and what would ITEMID=0x00020020 correspond to?

Thank you,

 

Istvan

 

• Foundation Fieldbus

István Orbán

• 7 Aug 2013 1:25 PM
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1 Reply

• István Orbán

  

  • 8 Aug 2013 1:45 PM

  I still do not know anything about the correspondence between ITEMID and the object index number, but I found out the correct object index numbers with the help of the instrument's manufacturer. I would like to read the sensor serial number and the calibration date/time.

  This is how they show up in AMS:

  

  I am asking the manufacturer why Cal Time is "25" and what does that mean, but this is not the only point.

  As I mentioned, the date and the time are defined as DOUBLE in the DD. However, if I configure them as FP, I get BAD signals with value 0. The best I could do is:

  

  The serial number comes through very nicely, but the time is gibberish and the date does not come through (if I configure it as string instead of FP, I get an empty string).

  I tried all the datatypes listed in BOL:

  FP — Floating point

  FS — Floating point with status (fieldbus only)

  DS — Discrete with status (fieldbus only)

  UI — Unsigned integer

  SI — Signed integer

  SG — String

   

  but none of them seems to work. Is there an undocumented date/time data type?

  Thank you,

   

  Istvan

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