Read CO2 Node register values with Modbus

I cannot read CO2 Node registers over Modbus. I’m just trying to get room temperature from a CO2 Node into a variable.

I have tried:
140 VAR5 = 197.13.MB_REG119
and
140 VAR5 = 197.13.MB_REG33
Panel number: 197
CO2 Node Modbus ID: 13
CO2 node is on Panel Modbus RS485 subnet
The variable value is always blank.

This is what I get in network points screen. The value never changes.

I can see the correct values in the register viewer no problem.

Can someone see what I’m doing wrong? Modbus is complicated to learn, is there a tutorial or resource anyone can recommend for learning how to connect devices and work with the registers?

Seems the two points are in the network points table already, but is not refreshed. Maybe there are too many remote points, it will be refreshed slowly.


Here’s a screen shot from my test here.

Thank you Chelsea,

I cannot find the register number for temperature setpoint in the register list. Is this available on Modbus, or only BACnet?

The CO2 Node is connected directly to the panel I am trying to read from. Do I still use the same addressing if it is not on the network?

Thanks!


Tools->register view

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