1566   BCR.actVal max value reached

Created: 16 Dec 2016

Status: Not Applicable

Part: Part 7-3 (2010; Edition 2)

Links: #968 BCR value range

Page:

Clause:

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Category: No impact on this part

Issue

I would like to know which is the expected behaviour for a BCR data when the value of "actVal" exceeds the maximum value (2^31-1 in Ed1).

A) One option is "do nothing". The new value for actVal will be 0.
b) Other option is using "q" (quality) to indicate overflow (INVALID in 7.3) but just in the first value reported (value=0, q=Invalid + Overflow). Then quality returns to Good.
c) Other option is using "q" (quality) to indicate overflow (INVALID in 7.3) for the rest of the values reported. The quality remains in Overflow until the reset of the device.

I think it is interesting to distinguish between an overflow and a posible manual reset of the counter.

Thanks in advance.

Proposal

Discussion Created Status
30 Mar 17 Not Applicable
The tissue is more than theoretical.
1) you should look tissue #968.
2) The format of actVal is INT64, a lot of space to collect pulses.
3) Even you start nearly to the end of the possible counts and an overflow will happen, no problem (this is conceptual behavior). Client can detect the overflow and take this into account. No change of quality is necessary. (option A).
19 Dec 16 Triage
Although it is "interesting" to know an overflow from a reset, this is a SCADA (telecontrol) issue. It is always assumed that the value is read often enough to recognize overflows.
My choice would be "A)".

Option B: useless if the value is not monitored at the exact rollover point.
Option C: q=INVALID means value is not to be used so any value after rollover becomes opaque. How would you reset the INVALID indication?
19 Dec 16 Triage

 

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