[ubuntu-uk] Reverse engineering data files

Gareth France gareth.france at cliftonts.co.uk
Thu Nov 27 08:14:32 UTC 2014


I have confirmed the earth and insulation readings are indeed F2 and F3. 
So far earth readings make sense but I just don't understand what is 
going on with the insulation:

Hex		Result
F3 01 48 79  - 99.99
F3 01 90 B7  - 42.79
F3 01 48 D8  - 99.99
F3 01 48 DB  - 99.99
F3 01 48 DB  - 99.99
F3 01 48 D6  - 99.99
F3 01 97 78  - 60.08

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...)
>
>
>
>



More information about the ubuntu-uk mailing list