question

alex376 avatar image
alex376 asked

EM24 RS485 über Modbus TCP Server

Hello, I have the following problem: I do not get my second EM24 with RS485 connection displayed in my Cerbo GX.

The first EM24 for the grid I have connected via USB on Modbus port 1, which works fine.

The second EM24 I have connected via RS485 Modbus TCP Server (Waveshare RS485 to ETH (B)). And configured on Modbus port 2. I just don't get it displayed in the Cerbo. The server seems to work because I can access the meter with the USC tool from Carlo Gavazzi via Modbus TCP and read the data.

I have activated Modbus in the Cerbo under the item Services-Modbus.

I get the meter neither with the Modbus scanner nor with manual input displayed. The Cerbo and the Modbus server are in the same IP network and have different adresses .

And I do not know now no more further. Who can help or give advice?

Thanks in advance.

Modbus TCPem24
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2 Answers
mike4nl avatar image
mike4nl answered ·

@Alex376
You wrote:
- second EM24 I have connected via RS485 Modbus
- Waveshare RS485 to ETH (B).
I have heared about some issues with the Waveshare but can't say it is yours.

Have you activated the end resistor for the RS485 on the EM24 and the Waveshare adapter?
- This could be an issues. A wrong terminated BUS can give a lot of trouble.

So far my first thougths.

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matzik avatar image
matzik answered ·

Hello Alex,

you wrote "The server seems to work because I can access the meter with the USC tool from Carlo Gavazzi via Modbus TCP and read the data."

I'm trying the same with a CG EM111 and a Waveshare RS485 to ETH (B). But I'm not lucky to access the EM111 from the USC tool.

How did you configure the Waveshare RS485 to ETH (B) ?

The Waveshare RS485 to ETH (B) and the GC EM111 are connected and the blue act-LED is flashing.

Thank you!

Matthias

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Related Resources

Modbus TCP Basics

Additional resources still need to be added for this topic

Energy Meter Manual EM24 RS485