Modbus TCP Tag Error : Null Value

Ignition
1

Hello everyone,
I hope this will find you well!

I’m trying to connect to a Modbus TCP enabled battery to retrieve data from it. I checked first the good connection through the tool “Simply Modbus”. As it can be noticed, the communication has succeed and the data have been well transmitted.

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However, when I created OPC server tags using Modbus TCP driver in ignition, I always find null values (note that the device is well connected) :

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The OPC item path that I use is for instance:
[Battery]226.HR259
226 is the UnitID, 259 is the modbus address for the variable “Battery Voltage”.

Could anyone help me please to fix this problem.
Thanks!

2

Function code 03 is IR not HR so try [Battery]226.IR259

3

@MatrixEngineering it unfortunately doesn’t work!
Note that in Simply Modbus for example, functions 03 and 04 give the same results.

4

Delete any other tag related to 226, try HR260, unclick span gaps and see.

5

Simply Modbus is also using 0-based addressing, so either configure the device in Ignition that way as well or add 1 to the addresses you’re using.

6

@allnet It works well. Thanks very much!

7

@Kevin.Herron Yeah absolutely. This was exactly the source of the issue. Thank you Kevin!