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Super newbi here!

Im trying to read som data of an energymeter.

Have the following setup:

VM22-Din energymeter (CARLO GAVAZZI) connected by rs485 to AK-Nord Din-Rail-Lan device server.

I'm using modpoll to try to read data from the energymeter so far without any sucess. At the moment i can see i "sign flashing" on the energymeter everytime I send a request so the AK-Nord Din-Rail-Lan device server is sending something... However i do not know where the fault(s) are it might be just about anything..

This is relly something new to me and any respons would be greatly appritiatet!

Hi Anders,

Have you installed any termination resistors on the RS-485 network? Their value should match the impedance of the cable, normally around 120 Ohms.

Hi Patrick,

I only have the device server and the vm24 connected to the rs485 line. On the vm24 end it's terminated as stated in the vm24 manual (As the last device on that line). On the AK-nord-din rail device server side there are some jumper settings that I'm not sure about regarding the rs485 interface:

DeviceServer jumper settings:
Jumper SW1-SW4
SW1 1+2 RS485 Pulldown resistor (560 Ohms)
SW2 1+2 RS485 terminating resistor (120 Ohms)
SW3 1+2 RS485 Pulldup resistor (560 Ohms)
SW4 1+2 RS485 ReadWrite (RS485 active)

However I'm far from sure how to use modpoll correctly to get a response from the vm22.

Should I use the -m enc or tcp option?

Device.ServerAdress.is: 192.168.51.211
Port.is: -p 1002
VM24.Adress.is (Modbus RTU address) 1


VM24-manual: http://www.gavazzionline.com/pdf/WM24%20CP%20ENG%200803.pdf

AK- Nord-din-rail-lan
http://www.ak-nord.de/en/daten/manual_xtmicro_ts.pdf

/Anders