Convert modbus holding register into float

[henk1000]

Hi,
I have been trying to convert data from a modbus register but still could not do it. I have tried the cast function it did not work.

Does someone has experience with these conversion?

Thanks

[PinguX]

Hi,

Have you tried reading 4 registers ?

As DBL is 64 bits long, it require 4 uint16.

[henk1000]

I have just tried the 4 registers and it did not work.
In the attached picture, the value in green is the real value in the device. The value in " *(type *) & " is what comes from the type cast.

[GerdW · Accepted solution]

Hi Henk,

most (all?) Modbus implementations I worked with so far use the IEEE-SGL format for "floats", so you should convert 2 U16 values into a SGL value in LabVIEW…

Edit:

Thanks for posting actual values:

Do you expect a value of 60 for the Modbus register reading?

[henk1000]

Hi GerdW,

Thank you very much for taking your time to help me. It works.