RS485 Master/Slave/Meter not working

I’ve set everything up as in the instructions.
Meter is not installed in the breaker box yet so I didn’t use it, but tested even that in the end.

In master I’ve set the slave start address to 2 and devices is 1
Slave address is set to 2

Master says that it failed to connect to slave 1
The slave says something in the lines “Slave time out”

Tried flipping master and slave between the two chargers.

I even tried connecting a Innepro Pro380-MOD just to see if that would work.
Also doesn’t work, get error for that also.

Then I decided to redo everything.

I actually went out again, opened up everything, tested the cables with a multimeter, double checked everything and took photos.

Also in the end pulled every cable out again and reinserted it, because I noticed on one of the photos it looked messy or badly inserted. So that has also been checked.


Slave also had orange light on top:

EDIT: The charging points are like 3 meters apart (In cable length)

Tried again, did factory reset, removed all the cables added resistor to terminate, switched from pair to single cable and used a single twisted pair for AB.

There’s nothing else I can try.

Tried one more thing to see anything interesting.

Swapped again the Master and Slave. Before the slave said “DLM slave device communication timed out” now the current slave does not say that. Just the master now gives error “DLM slave device 1 communication fail”

Makes me think the one that was giving the “DLM slave device communication timed out” when it was slave is faulty. Or maybe both just this one didn’t figure it out yet. I have no idea. The errors are to vague.

I’m prepared to give SSH access to both of them if required by tech support.

Checked if any signal is coming from the RS485 line and there is. Just nothing seems to talk to anything.

Also the voltage on A and B between GND is moving between about 1.85v and 2v which is kinda low range.

Between A and B there’s 0v.
But this is testing from the Meter location, open cables at that end, so not sure if this is accurate.

Tried now with an insulated alarm cable, basically meant for this. There’s something wrong with both of these as both of them also failed to connect to the Inepro meter.

So the Inepro has been installed and none of the two connect to it.

I’ve also checked the troubleshoot file, it’s some obscure symbols but what stood out was hw_rev says its 000


Could you please try to use same pair for A and B (F.E blue to the A port, white&blue to the B port)
Also could you try to disconnect the grounding?

What about the general energy meter parameters, are they the same for both devices?
Could you attach log file from both devices? (it has to be encoded from our side and you wont be able to read it)

Hi @DonatasL

Thanks for the reply.

Yes I’ve reverted to using only 1 pair for A and B like you’ve mentioned but didn’t work.

I already did my original testing without ground, added ground when creating this forum thread.

Also tried with resistor to eliminate any echo which didn’t help.

The energy meters are the same on both, but the Master is the one reading the load of the building and communicating to the Slave.

I’m attaching two files in the ZIP, one for master and one for slave device. (3.0 KB)

From the LOG’s i could not see the problem.
Could you please check if the resistance between A and B are ±120 ohm?

Hi @DonatasL

On both od them 120ohms resistance between A and B
These two were already in RMA once, boards replaced. Is it possible that boards were flashed wrong?

Good morning,

I could see all the information from the TS, so the boards are flashed correctly.
I would like you to do the testing (if there is a problem with RS port, we will see)

  • Connect first charger to the Smart energy meter (check if there is a warning)
  • Connect second charger to the smart energy meter (check if there is a warning)
  • If only one of the chargers will be with the warning after that testing, we have to doublecheck if the settings are the same (from what i could see in the app they are the same) (i only unable to see the Energy meter type (is either 3phase or 1phase)
  • We even can jump in a short teams meeting, to troubleshoot together (tomorrow would be best 2024.07.02)

Hi @DonatasL

So here’s an update.

I swapped master/slave on the two chargers and the new master works now, the new slave still does not.

I’ve disabled Master on the one with Serial number ending on 63 and enabled it on the one ending on 62 (The other way around)

62 = Master and it works, communicates with Inepro 3 phase meter.
63 = Slave, doesn’t communicate.

So 62 works as intended 63 does not.

Seems somehow in the past I must have tried twice the same one, when I said both have issues.
It seems only the one ending in 63 has issues, as it doesn’t communicate with the other charging point or the meter.

Please advise what to do next.

EDIT: After enabling Dynamic Load management makes the master not work correctly either, because it can’t communicate with the slave. So I have to keep the non-functional one off and disable Dynamic load management for the working one to work correctly at least.

Tried the latest TeltoCharge-v1.12.7 firmware, didn’t help the faulty one.