RS-485 Meter Time encoding differences for V3 and V4 meters?

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simonprickett
Posts: 5
Joined: Mon May 15, 2017 12:53 pm

RS-485 Meter Time encoding differences for V3 and V4 meters?

Post by simonprickett »

Hi there,

I'm parsing data from RS-485 reads for both V3 and V4 meters, and hope you can clarify how to treat meter_time. In the RS-485 Parsing PDF for V3 meter I see:

14B Time (02/17/2011, Thursday, 11:46:37)

31 31 30 32 31 37 30 35 31 31 34 36 33 37

So is this 1102 = the year backwards... would 2012 therefore be 32 31 30 32 or 31 32 30 32 ? I can see how to decode 11:46:37 from 31 31 34 36 33 37, but I'm not sure how to arrive at 02 17 for the month and day from 31 17 30 35 which is 17/05? Is this a mistake in the V3 PDF file, or am I interpreting it incorrectly?

The PDF that I have for V4 meters shows the following for meter_time in request type A:

Date/Time (14B)

31 31 34 30 37 31 35 32 32 33 33 30 30 30

with no example decoded date value.

Similarly for request type B on a V4 meter I see:

Date/Time (14B)

31 31 34 30 37 31 36 33 32 35 31 30 30 30

also with no hint at what value this contains.

Am I correct to assume that V3 and V4 meters encode these dates differently? If anyone can provide a breakdown of where YYYY MM DD HH mm ss values are in the above, I would be very grateful.

Thanks,

Simon.
Jameson
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Joined: Fri Nov 04, 2011 7:42 pm
Location: Santa Cruz, CA
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Re: RS-485 Meter Time encoding differences for V3 and V4 meters?

Post by Jameson »

Im going to start with my v4 meter here that is set to local time.

Right now it is Thursday, May 25th 2017 at 17:01. I used the EKM Dash to set my meter to my local time. Then I used the EKM Dash Hex Inspector to extract the Date/Time portion of the Hex that I need.

You can parse the date like this: 31 37 is the year (in red), 30 35 is the month (green), 32 35 is the day (purple), 30 35 is the day of the week (blue), 31 37 is the hour in military time (brown), 30 31 is the minute, and 30 35 is the seconds.
Screen Shot 2017-05-25 at 5.06.41 PM.png
Screen Shot 2017-05-25 at 5.06.41 PM.png (14.4 KiB) Viewed 25450 times
I see what you mean by the documentation being off in the v4 parsing document. This string at the beginning of the timestamp 31 31 34 30 (does not make sense) we will correct it. As far as I can tell the v.3 parsing document looks correct. There is no 2017 for the year, only 17 (hopefully that does not come back to bite us at the end of the year 2099)

Thanks for pointing this out! Sorry for the trouble.
Jameson
EKM METERING
http://www.ekmmetering.com
831.425.7371
simonprickett
Posts: 5
Joined: Mon May 15, 2017 12:53 pm

Re: RS-485 Meter Time encoding differences for V3 and V4 meters?

Post by simonprickett »

Thank you! Just to further clarify so the V3 also a 2 year date, so:

14B Time (02/17/2011, Thursday, 11:46:37)

31 31 30 32 31 37 30 35 31 31 34 36 33 37

Decodes as:

31 31 = 11 the year
30 32 = 02 the month
31 37 = 17 the day
30 35 = 05 day of week
31 31 = 11 the hour
34 36 = 46 the minute
33 37 = 37 the second


Regards,

Simon.
Jameson
Posts: 860
Joined: Fri Nov 04, 2011 7:42 pm
Location: Santa Cruz, CA
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Re: RS-485 Meter Time encoding differences for V3 and V4 meters?

Post by Jameson »

Hello Simon,

Thank you again for bringing this to my attention, will you please take a look at the corrected pdf and see if it makes sense?:

http://documents.ekmmetering.com/Omnime ... arsing.pdf

You can always use the EKM Dash > Help > Hex Inspector to see what the Hex data from your meter looks like and how the EKM Dash is parsing out the data. It is very helpful to have a meter working with the Dash, then essentially copy how the Dash parses the data. This is a huge leg up vs starting from scratch with a meter that you do not have working or dont understand the protocol.

Hope this helps. Thanks!
Jameson
EKM METERING
http://www.ekmmetering.com
831.425.7371
simonprickett
Posts: 5
Joined: Mon May 15, 2017 12:53 pm

Re: RS-485 Meter Time encoding differences for V3 and V4 meters?

Post by simonprickett »

Hi Jameson - sorry for the slow reply here, I reviewed the updated document looks good, thanks for the tip re EKM Dash also.

Simon.
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