[SOLVED] Oneshot modbus rtu read or write from plcpgm

Hi,
I got rusty, 4 years after I last used proviewr I forget a lot and now I am facing a pretty simple problem:
I have several modbus rtu slave devices, where I want to read their coils sometimes. Not periodically, but triggering by some events.

Keep it simple, here is a screenshot about the test environment:


Here you can see clearly, what I would like to achieve:
- I would like to be able to set (trigger) the SendOp attribute of the modbus_rtu_module (called State)
- I try to access the SendOp attribute from SetDp, but I always got Input Syntax Error
- I tried several variations, but all of them are failed with Input syntax error

I assume I missed something trivial and/or using the wrong object (SetDp).
The goal is to trigger SendOp without DArithm or something like this, but using something pure from the standard Object Palette.

Needless to say, Copilot, ChatGPT, Z.ai chat, and Leo all failed gloriously, with massive, beautiful hallucinations and an incredible level of confidence.

Thanks,
István

Never mind, it was pretty obvious, the full path was necessary with the Attribute at the end, like this:  
Nodes-Bhu451-IO-rs485ch1-KS01-State.SendOp

Here you can see in the test plcpgm.