Hi,
I am new to this and seem to be a bit stuck trying to get communications going between a NetBiter RTU/TCP Modbus gateway and a Schneider PM9C power meter. I am using Modscan32 to test my installation but get an "exception response from slave device". To be honest I don't know where to start looking. The gateway is setup and works fine, the powermeter is connected to the RS485 interface with a two wire cable. Am I missing something?? The address I want to read is anything from 1000 and up, according to the manual it is the voltage etc. registers on the meter.

Ingo

 

try addresses 31000 or 41000 instead of 1000

 

I tried both and it gives me 'gateway target device failed to respond' error. I can see the Netbiter internal registers but nothing from the PM9C.

The strange thing is that the Netbiter 'Serial Link Status' LED flashes orange every time I poll it. If I poll a non existent address it polls red. I also see CRC errors increase via the Netbiter web interface every time I poll it.

 

I got it. I had the RS-485 wires crossed and polled data that wasn't there. Polling the right registers returned data without any errors.
There's nothing wrong with a few days of pulling your hair out...