RTU Master does not work

[prathyusha]

Hi,

I am using RevPi Connect to read RTU slave vibartion meter. I followed the tutorial as described on: https://revolutionpi.de/forum/viewtopic.php?t=935
Additionally, I also followed the tutorial from Youtube: https://www.youtube.com/watch?v=kCodHu6b3XM&t=330s.

I am getting slave vibration values as 0 in the putty terminal

For your information: I am using Industrial Vibration Sensor QM30VT2 as slave.
Configuration done on the Revi Pi which is a RTU Master:

1. device path settings: /dev/ttyRS485 , parity = none

device_path.jpg (634.03 KiB) Viewed 2842 times

2.Extended data settings:
slave address = 1, function code = holding register,register addr = 40043, Quantity of Registers = 1, Action Interval = 1000, Device value =Input_word_1
3. Save as: start-config > Reset Driver.

Output:
Vibration values = 0 always

[->Johannes<-]

Hi @all,

Prathyuahsa and I had a conversation about our Kunbus support ticket system.

Long story short.
If you have problems with a Modbus slave, then keep this in mind

In our products, we use 1 as the first register address. Some manufacturers use 0 as the first register address for their products.
Check how the addressing is specified for your slave. If the slave you want to use uses 0 as the first register address, you must add 1 to the specified value during configuration.example: In the documentation for the slave, there is a register address 30053. According to the documentation, the addresses start at 0. You therefore use the address 30054 for this register when configuring a Modbus command.

and have a look here:

How to Use RevPi Connect as Modbus RTU Master

Regards

Johannes