Writing the same value to a modbus register using Crimson 3.1

[erwilfo]

All,

I must write the same value to a modbus register using on a Graphite HMI. Crimson prevents this, but according to technical support, the function "Force" should allow me to do it.

If I do a regular assignment (Register := Value it works as long as the new number is different to the one is currently store in Register. The device I am communicating with keeps a historic on changes in this register so I need to be able to write the value even if it is the same it is currently stored. I implemented the "force" function, and it is not writing even if the new value if different.

Has anyone dealed with this problem? Any input will be appreciated.

Thanks!

 

[Ken Roach]

Welcome to the PLCTalk Forum community !

What exact Red Lion device are you using ?

Is the protocol Modbus RTU or Modbus/TCP, or something else ? What is the Modbus function code (coil, analog, holding, etc). ?


If you can provide a snippet of the code you're executing, folks might be able to help or test. I don't have any Crimson 3.1 devices but I've got a handful of ordinary 3.0 stuff.