Modbus Serial Comms

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AVandyke
Newbie
Posts: 1
Joined: Mon Jun 20, 2022 9:49 pm

Modbus Serial Comms

Post by AVandyke »

Hello. I have only just started using the picoScope. I am not sure if I am using the probes correctly? I am trying to read Modbus data. The data is only being sent as a burst, not continuously. I want to see the graph data so that I can see the function code, address, and modbus value. But as soon as I put the probe on the signal line I loose the graph data.
Modbus.PNG
I did notice that if I do not put the probe on the data line, I can see the frame data being captured for small bursts of noise on the gnd wire. Some help and advice will be most appreciated.
Noise.PNG

bennog
Advanced User
Advanced User
Posts: 206
Joined: Mon Nov 26, 2012 9:16 am
Location: Netherlands

Re: Modbus Serial Comms

Post by bennog »

message looks to short for modbus ASCII possibly modbus RTU.

Can you post a .psdata file ?

Benno

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