DTM Browser to make Multiple Modbus Poll

[haksarfarooq]

I'm trying to use DTM browser to make make modbus poll from RTAC. I'm able to get the points in first poll object. But not able to get anything in the second poll object.

I can only use 125 registers on one object, so i'm forced to use more than one poll object.



Thank you

 

[drbitboy]

Why is the Unit ID different for the second poll (254 vs. 255)? Doesthe Modbus Slave ignore the Unit ID?

P.S. the Modbus protocol has a by-design upper limit 125 registers or 2000 bits (= 16 bits/word * 125 words) per transfer.