EmonTx shows inactive on Emoncms


I have two EmonTx devices (named tx17 and tx18) installed and feeding to one EmonBase - they used to work intermittently, often losing signal and creating new random feeds, with tx17 more consistent and tx18 often becoming inactive for long periods of time. After doing some changes which involved relocating the devices (making the two tx not as close to each other, and putting the base in the same room), the tx17 has had no issues and is collecting data perfectly every 30s, however, the tx18 has been inactive. The device is connected and the little light is flashing as normal.

I have followed the “Configuration” guidance, changing the node ID with the DIP switch as advised but that didn’t do anything. I am also a novice in all of this and so haven’t done anything different to what the guidance documents indicate, so I am not sure what to do.

Thank you for your help!

Welcome, Romane, to the OEM forum.

Which version of emonTx do you have? And what software version are they using?

Did you power down the emonTx after changing the DIP switch? The switch setting is only read once, at power-up, so unless you restarted the sketch, it would not know the switch had been changed.

Hi Robert, thank you!

They are EmonTx v4 - in terms of the software version, I am not sure, how do you see it without admin access (my colleague who has the admin account is on leave currently). We haven’t changed anything to the default settings since we bought and set up the devices in January 2023, I don’t know if that helps.

In terms of powering down, we had to remove the power to open the device and change the switch so I assumed that would be enough, is there a further manipulation I should do that is not unplugging the power and plugging it back?

No, this should have been enough.

As they are emonTx4s, there is as far as I know only one software version as yet, and when I look at the sketch, there’s a possible problem. It looks as if, through no fault of yours and depending on where you looked, you might have got the wrong DIP switch. The PCB legend appears to be correct, and if you followed this, then it should have changed the Node ID. One obvious question - you did get the switch in the correct position? This has caught me out before now, but I’m not at home just now and don’t have access to an emonTx V4 to check.

If you did get the correct switch and you’ve checked both positions, then you need to look in emonCMS at what the emonhub log is reporting (if anything) for the two emonTx4s.

Sketch Lines 160 & 161:

const byte DIP_switch1 = PIN_PA4;  // RF node ID (default no change in node ID, switch on for nodeID + 1) switch off D8 is HIGH from internal pullup
const byte DIP_switch2 = PIN_PA5;  // Voltage selection 240 / 120 V AC (default switch off 240V)  - switch off D9 is HIGH from internal pullup

This says Switch 1 is NodeID+1, but it’s not lower down in Line 183:

if (digitalRead(DIP_switch2)==ON) EEProm.nodeID++;  

The PCB Legend is SW2 is “RADIO ID SELECT” and it’s wired to Switch 2 (Pin PA5)
Lines 221 - 224

  // Sets expected frequency 50Hz/60Hz
  if (digitalRead(DIP_switch1)==ON) {
      USA=true; // 60 Hz

and this changes the expected line frequency, NOT the voltage (which emonVs no longer requires anyway).

So it looks as if the comments in lines 161 & 162 are wrong and misleading.