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TaCaPica
Posts: 36
Joined: 11/18/09
ModBus Message
04/09/12 5:01 AM
Hi
I have a CR800 as a ModBus slave that gives info to a PLC. To save registers and as i can send info on/off as a sequence of 0's and 1's im composing a message using the 32 bit message. But i stumbled in a problem: when i try to compose the message above the 24th bit all the message goes to 0 (just to the 23thr bit all is well!).
The PLC reads the registers as float numbers so im defining the register as a float.
Can it be this the problem?
RE: ModBus Message
04/10/12 5:54 AM
The IEEE754 standard for 32 bit floating point values specifies that the number has a 24 bit mantissa, a seven bit exponent, and a single bit sign value. It can represent integer values accurately but is going to be limited in the range of integers that it can represent. Because of this, you will need to use two registers to represent 32 bits.
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