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I have tested a TRB140, supplied with 12V DC. On one output I connected a 12V DC relay (with protection diode). I was able to switch  it on, however the voltage on the relay was 1,5 V less than the supply voltage. The relay draws 100mA (measured). I did not cut the PR2FK20M so maybe this voltage drop is partly caused by cable and connector losses.

If I would extrapolate this result  500mA current  would be far too much ?

In the off position, the idle current, when just a resistor in series with a LED is connected, 100myA flow, which causes the LED to falsely emit some light.

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Hello, 

For this solution of yours, TRB140 cannot provide output voltages on its input/output. 

Kindly refer to this link for more information about connecting a relay to the device and it may help you: 
RUT240 Relay to Open Collector Output - Teltonika Networks Wiki (teltonika-networks.com)

Also for the current issues, you are having kindly make sure they are having the same groundings.

Digital open collector (OC) output: 30 V, 300 mA

Let me know if you have some questions and clarifications about this. 

Regards,
Mellow

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Hello Mellow,

I connected the relay the same way as You have mentioned in the link. I am experienced and well equipped for such measurements.

When a relay with less current draw (eg 60mA) is connected, no problem as the voltage drop is less than 300mV. The point of my remarks is that the current through the OC connection should be much less than 100mA.

BTW, Did You test such a setup yourself ?

regards

EvalG
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Hi Eval,

I am not able to test this kind of scenario at my side. I will be communicating with HQ about this. Would it be possible to share the actual photos of the wiring connection you made and the actual scenario where you mentioned the LED is falsely glowing due to 100mA current.

Kindly share these details via PM.

I will be waiting for your message.

Regards,
Mellow
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Hello Mellow ,

the point of my questions is that, I would like to have more accurate information about the circuit topology and the properties of the OC outputs.

by
Hello,

Thank you for the provided schematic diagram. I am currently checking this with HQ to provide you a more detailed information.
Once I have feedback from their side I will let you know

Regards,
Mellow
by

Hello,

For this issue of yours, I have received feedback from our RnD team they are asking if you added a protection diode before the said relay. 



Let me know the results

Regards,
Mellow