Factor 10 on power on emonhub with emonTx5?

Hardware emonTx
1

Good evening,

I’m new user on EmonTx5 12 CTS (with EU emon VS, 20A CT) and during test, I have a factor 10 on the power of electric heater. Anyway the emonTx code doesn’t seem to include this factor 10. We are wondering if it is the correct repo for the emonTx5 for single phase or not?

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Here is our setup for emonhub :

[[28]]
    nodename = emontx5
    [[[rx]]]
        names = MSG, Vrms1, Vrms2, Vrms3, P1, P2, P3, P4, P5, P6, E1, E2, E3, E4, E5, E6, pulse, Analog
        datacodes = L, h, h, h, h, h, h, h, h, h, l, l, l, l, l, l, L, H
        scales = 1.0, 0.01, 0.01, 0.01, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0
        units = n, V, V, V, W, W, W, W, W, W, Wh, Wh, Wh, Wh, Wh, Wh, p, n

Is there an official repo for emontx5 firmware ?

Best

Antoine

2

I was with Antoine when this happened and I couldn’t be sure that this was the right way to configure emonhub for emontx5, which is why we’re asking the question.

I guess there is a factor 10 but as all the docs we found specify the power is send without that factor 10, I wonder if it is correct

3

Welcome, Antoine, to the OEM forum.

Have you got the correct c.t. (a) fitted and (b) set in the emonTx5’s calibration?
Say you have the calibration in emonCMS (Admin → Serial Config) set to 200 A, do you have a c.t which gives 333 mV at 20 A? This would show 10× the correct power!

What do you mean? The software used in the emonTx5 is, as far as I know, this: GitHub - openenergymonitor/avrdb_firmware: EmonTx4, EmonPi2 & EmonTx5 combined firmware - what you called the emonTx code.

Unless someone has hacked into Github and changed that or emonLibDB, then it should be giving the power in watts - provided the calibration set in the sketch in the emonTx5 is correct. The number for the c.t. amplitude calibration is the same as the c.t. rated current in amperes. The voltage calibration when using the emonVs is 100 whatever your line voltage. Both numbers may be adjusted by a small amount to calibrate for best accuracy.

The voltage at 10 times what it should be would also cause the power to be 10 times the expected value, but I can see this is correct (certainly not wrong by 10×).

Can you look in the emonhub log and check the numbers there?

It is basically the same sketch for single, split or 3-phase systems. Until you have line-line loads (no neutral connection to the load), the emonTx5 (& 4), i.e. emonLibDB, works as 6 or 12 single phase wattmeters, connected as you instruct in the sketch.

4

Thanks Robert for the fast answer.

Can you look in the emonhub log and check the numbers there?

Yes we are having the same values (x10) in the emonhub log

I understand now we have not properly set the calibration in emonCMS. We must have plugged a 20A CT in a connector fitted for 200A.

My mistake so as I thought this kind of calibration was only relevant for the emonpi2. We are not running emoncms on an emonpi2 but on a amd64 laptop through docker containers, with an RFM69 LPL USB key

@antoinev : it is something to find in the admin module of emoncms :

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You have to stop the emonhub container and to restart the emoncms image with /dev mounted on it otherwise it will not see the usb key

Maybe it is possible to configure the emontx5 with the online configuration tool that is proposed for the emontx4 ? I dont know if it works ?
See Configuration — OpenEnergyMonitor 0.0.1 documentation
It requires to connect the TX5 to the laptop with a USB-C to USB-A cable
In that case, you don’t have to use the admin module of emoncms.

5

It seems as if you have confused the hardware (emonPi1, emonPi2, laptop) and the software (emonCMS). emonCMS will run on whichever hardware it will run on, and do exactly the same things.

It should work, but I had trouble and I’ve seen a recent report that some commands don’t work when using a terminal program on a laptop. If it appears not to work, experiment with different baud rates (should be 115200) and different line endings (CR, LF, both). See
CT Calibration selection from Pi2 - #4 by Robert.Wall and following posts, and I had the trouble with the Arduino IDE and an emonTx4 - in both cases the “avrdb combined” software is involved.

6

No, I dont confuse emoncms software and the different OEM hardwares

What was confusing is that i did not understood that the admin module of an emoncms could communicate the calibration settings to an emontx5 via radio…

when the tx5 is linked to a computer via usb, it is more evident that you can transmit a calibration. Doing things over the air through the admin module seems more obscure for me…

Correct me if i am still misunderstanding things :slight_smile:

7

Moreover the admin module is for me not that portable from a hardware to another one. It is designed for the raspberry pi, relying on many debian fashioned tricks.

8

I wasn’t aware that it could, and I think you might be wrong. I have never seen it mentioned. @TrystanLea ?

9

To clarify, the serial config tool cannot configure a remote device over radio. It must operate on a port (serial or usb) connected to the system upon which EmonCMS is running.

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10

I was ‘out of the loop’ concentrating on getting emonLibDB working while Trystan did the hardware and it was he who added the configuration code to my demonstration sketches.

Although technically it should be possible to configure a remote node by radio, there are plenty of reasons why it is almost certain it will never happen. And this is why I doubted Alex’s statement.

1 Like
11

Thanks Robert, I effectively miss the point that each CTx port on the EmonTx5 are configure for a dedicated CT power. Since I connect the CT of 200A on the CT1 dedicated to the 200A measures, it works fine with the correct order of power.

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