Hi there, I have a situation here. I am using PLC Edge Controller and I want to read data from my slaves Autonics ARIO-C-MR through Modbus RTU. I have managed to read the data when I write a code just to read just 1 slave. But when I try to read 2 slaves at one time, the first slave seems to be no …

Finally, I am able to read the data from Modbus Configurator. The solution is only to change the cable from normal cable to profinet cable. Thank you for your suggestion all this time.

[image] anssikone.fi: wVariable1 := %IW1 ; wVariable2 := %IW2 ; wVariable3 := %IW3 ; Negative, definition in PLC_PRG VAR wVariable1 : WORD ; // Only for testing Modbus register update wVariable2 : WORD ; wVariable3 : WORD ; END_VAR Unused variables are not updated.

I actually applied the same thing using Modbus TCP and it successfully worked. But for Modbus RTU, it doesnt work. I am not sure why. I have checked the paramater communication settings, I have followed the one that I used in function block where I can read the data. But in the end, Modbus RTU usin…

I’m agree that TCP case. What is your communication parameter setup exactly ? 9600,N,8,1 two wire half duplex ?? Be sure that RS485 A and B are okay. Second slave looks strange…

Hello, Can you post your Modbus mapping configuration? I am wondering what the Function Code is, and whether the device supports it. Also, FC 23 is not possible with half duplex RS485.

Hello, this is my Modbus mapping configuration where i cant even read 1 slave. [image] This is my modbus using function block, where i can read slave 1 perfectly. [image]

This is my communication parameter setup when im using function block, where i can get data from slave 1 successfully. [image] This my communication parameter setup when im using Modbus tree, where i couldnt even read data from 1 slave. [image] This is the error that appeared when I run the mod…

In status tab. What is the last error ?

The one that im showing is already in status tab. [image]

Click (+) Last Error and see details

Owh, my bad. This is what it says [image]

Could not Read data from 2 slave Modbus RTU

CODESYS

umairyamin January 19, 2024, 2:06am 29

Now “Response CRC Fail” appeared.

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Could not Read data from 2 slave Modbus RTU

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