[ubuntu-uk] Reverse engineering data files

Gareth France gareth.france at cliftonts.co.uk
Wed Nov 26 12:38:15 UTC 2014


Earth and insulation are two different tests. The insulation results on 
the Supernova measure up to 99.99 Mohms. The fact it is reading above 
the scale is relevant and important information. So the earth reading is 
0.05 or 0.06 depending on which test you are looking at, the INSULATION 
is GREATER THAN 99.99. This 19976 you reference can't be either of 
those. You have inspired me to look at this from a different perspective 
and this has gotten me round a lot of the issues I was having. I had 
totally forgotten about it but the machines I sport a 'test code' 
function to specifically specify the tests you want to do. I have never 
used it but I have a sneaking suspicion it looks exactly like the long 
string we see.


On 26/11/14 12:29, Paul Sladen wrote:
> On Wed, 26 Nov 2014, Gareth France wrote:
>>> f2 80 05   f3 4e 08   f6 80 49 00 08   f8 80 00  (Washing machine)
>>> f2 80 06   f3 4e 08   f6 80 01 00 08   f8 80 00  (Fridge)
>> ID	Earth	Insulation	Load	Leakage	Continuity	Descript
>> D7785	0.05	>99.99		0.05	0.73	(No result)	Washing Machine
>> D7786	0.06	>99.99		0.05	0.1	(No result)	Fridge
>
> I recall this thread started with the premise of obtaining extra
> detail ("...several features which are only downloadable in their
> custom format").  I don't think we should be surprised when we do
> find that extra precision is available in the file, beyond
> the rounded/simplified values shown on the display/report output.
>
> Reviewing the specification for another Seaward PAT tester suggests
> that the Earth Insulation measuring range is going to be in the range:
>
>    http://www.protrol.co.uk/Seaward%20PAT%20Testers.htm
>    Seaward SuperNova Plus - Pat Testing Equipment
>    Range 40mΩ - 19.99mΩ  <---------------
>    Resolution 0.01Ω
>    Accuracy +/- 5% of reading, +/- 2 digits upto 5.00Ω
>
> Therefore we can expect that the sampled value is likely
> somewhere between 40 and 1999 units.  And indeed we find:
>
>    0x4e08 (19976 decimal)
>
> So it would be reasonable to conclude that the test equipment measures
> and stores a value between 0 and 19999 kOhms, and that the measured
> value is simplified (for display purposes only) to a percentage.
>
>> Also in there may be visual test pass/fail,
>
> In the sample provided D7782, D7783 were both failed with broken
> strain reliefs; these two records show '0x02' while the rest show
> '0x01' at the expected position (so this is the visual pass/fail).
>
>> (25A, 10A, 100ma) but this is probably stored in that large string.
>
> I don't have domain-specific knowledge about how test-parameter
> strings are configured, but they clearly follow a pattern:
>
>    http://www.funfoodcatering.co.uk/wpimages/wpcb6d03ea_06.png
>    "K8B7000021 S121111111"
>    "K3C7000021 S121111111"
>    "I1C7003061 S121111111"
>
>    "H172008021 S121111111"
>    "H1C2008021 S121111111"
>    "I010000022 S121111111"
>
> To establish the mapping for (25A, 10A, 100ma) only requires
> performing the three tests (without changing anything else) and
> posting the results! [1]
>
> 	-Paul
>
> [1] (I can't do this as I don't have the device...)
>
>
>
>



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