Search found 10 matches

by nielo
Tue Aug 06, 2019 3:42 pm
Forum: Electric Meters
Topic: Accuracy
Replies: 1
Views: 179

Accuracy

I have two EKM "Smart" meters installed at my home. One measures the power from my solar panels and one measures power to and from my home. I've had both meters installed since late 2013 and have been collecting data ever since. A few days ago I thought I'd compare the Utility readings to mine in or...
by nielo
Fri Jun 07, 2019 9:25 pm
Forum: Developers Sandbox - Meter Data
Topic: Raspberry Pi and FTDI USB (or Serial)
Replies: 12
Views: 7965

Re: Raspberry Pi and FTDI USB (or Serial)

An update. I used 100 ohm resistors (Cat 5 characteristic impedance is 100 ohm) to terminate both ends of the buss and the dropped packets almost went away. I still have a bunch or retries (a failed packet, either length or CRC, and I retry once after a 500 ms delay) all of which, after I terminated...
by nielo
Thu Jun 06, 2019 1:27 pm
Forum: Developers Sandbox - Meter Data
Topic: Raspberry Pi and FTDI USB (or Serial)
Replies: 12
Views: 7965

Re: Raspberry Pi and FTDI USB (or Serial)

I'll start by saying that, in this particular case, I can dramatically effect the reliability of the link by moving the wires closer or further away from the radio antenna. The problem was most noticeable when I used a radio with a wire antenna as opposed to a whip. With a wire antenna the RS485 cab...
by nielo
Wed May 29, 2019 12:47 pm
Forum: Developers Sandbox - Meter Data
Topic: Raspberry Pi and FTDI USB (or Serial)
Replies: 12
Views: 7965

Re: Raspberry Pi and FTDI USB (or Serial)

The data is stored on a local server. I haven't made the data available on the web because, at least so far, I haven't had the need to do that. I haden't though about putting anything on GitHub but maybe I will eventually... after I clean up the code a bit. ;) I'm still having some minor issues with...
by nielo
Fri May 24, 2019 4:31 pm
Forum: Developers Sandbox - Meter Data
Topic: Raspberry Pi and FTDI USB (or Serial)
Replies: 12
Views: 7965

Re: Raspberry Pi and FTDI USB (or Serial)

Dunno if anybody is interested but if they are I'm willing to share. The screen shot is a chart generated on a system running on a Raspberry Pi 3B+ that is collecting data from two EKM Meters (a v3 and a v4). It shows generation from my solar panels, power in/out from the utility (HELCO - Hawaiian E...
by nielo
Tue May 21, 2019 6:34 pm
Forum: EKM Metering Systems
Topic: Questions for a new installation
Replies: 18
Views: 14034

RS485 Terminating/Bias Resistors

Do the v4 and v3 meters have terminating/bias resistors on their RS485 terminals?
by nielo
Wed Jul 11, 2018 6:00 pm
Forum: Developers Sandbox - Meter Data
Topic: EKM-Omnimeter RS-485 Data
Replies: 44
Views: 55367

Re: EKM-Omnimeter RS-485 Data

The crc calculation for EKM meters is pretty confusing so I thought I'd post a routine for Arduino to help anyone who needs it. You should be able to copy what's below and paste it into your sketch without modification. The only thing you'll need to add is a global character array declared as "char ...
by nielo
Sat Sep 20, 2014 12:23 pm
Forum: Developers Sandbox - Meter Data
Topic: slow comms
Replies: 7
Views: 6176

Re: slow comms

I think it might, you would have to essentially create 8 separate RS485 networks per USB spider (unless there is some sort of limitation to the USB spider I am not aware of). You would have to use 8 of these: http://www.ekmmetering.com/ekm-metering-products/remote-meter-reading-solutions/ekm-serial...
by nielo
Fri Aug 29, 2014 2:18 pm
Forum: Developers Sandbox - Meter Data
Topic: slow comms
Replies: 7
Views: 6176

Re: slow comms

Nope, a star configuration like your data concentrator doohickey provides won't work to increase network throughput. In any network topology be it star or bus or mesh or whatever, without some sort of collision avoidance/bus arbitration, data will collide and be useless. The implication of that is, ...
by nielo
Wed Aug 27, 2014 9:01 pm
Forum: Developers Sandbox - Meter Data
Topic: slow comms
Replies: 7
Views: 6176

slow comms

I have 2 of your meters running (a v4 and a v3) on the same RS485 network and they work fine as far as accurately reading electrical flow, but I need faster communications. If the point is simply to collect kWh usage then collecting data every few minutes, maybe even every few hours, is adequate. Bu...