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
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?