[How to combine 2 different WORD to create a single FLOAT]

On 7/2/2021 at 2:27 PM, RikiWatasuta said:

Hello all. First time post in this forum.

I am hoping someone here can offer some advice or a solution to a problem I am having.

I have a Modbus water meter from chinese that connected to word fusion generator FX5U with ADPRW Instruction, but i have a problem. The cumulative flow from water meter is a 4-byte hexadecimal number, with the high bit first and the low bit last.

I want the output from the PLC is real number FLOAT. can someone in this forum help me to combine 2 different WORD and create a single FLOAT.

Here I Attached document from water meter.

 

Thank you,

Modbus协议英文Modbus water meter communication protocol.pdf

Re-write from DB to global MEMORY your word like DBx.DBW1>>MW10 and DBx.DBW2>>MW12, then create real format for global memory MD10 (it take's 2 words)

 

Have a DWORD value.
Load the high word value into the DWORD.
Shift the DWORD left by 16-bits.
Mask in the low word into the DWORD.
User DWORD_TO_REAL conversion to convert it to the real value.

MyDword := HighWord;
SHL(IN := MyDword, N := 16);
MyDword = MyDword AND LowWord;
MyReal := DWORD_TO_REAL(MyDword);