Modbus RTU issues


I have a 3 phase energy meter - ACREL DTSD1352 /ADL3000 - it is configured as 9600,N,8,1 on Address 1.

I have a Linux (Ubuntu 18.04) on a laptop.

I have a USB/RS485 dongle - this is installed and presenting itself as /dev/ttyUSB0

From the commandline i can use a program mbmd - that is designed to query energy monitors etc and works well.

My monitor is not natively supported - however using a development feature i have been able to succesfully query the meter and return information - some DWORD, other WORD registers etc - all seems fine.

I am now on the same machine trying to use NR to query this unit - i have tried a number of modbus modules - i currently have both of these installed

And have done the following test flow


But am getting absolutely nothing back in the debug window - i have tried a number of different registers and all of the options that the nodes supply

I have tried NR running as a normal user and also as root - and this has made not difference

Any ideas how i can troubleshoot this one ?


A couple of things here

Change the logging option in NR to debug so you can get better info.

Turns out to be a Linux permissions issue on the USB/Serial driver - apparently the only group with access is the Dialout group - so whichever user you use to run NR, should be given permissions/membership to that group.


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