I am facing similar problem, want to read inverse float register, or swapped float register ( IEEE 754), there is no data type like that in wincc professional v15.1,

any help will be appreciated.

Kind regards

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Split from WinCC_OA float inverse.

Dear Murof

Thank you for replay, the communication driver used is Modicon Modbus RTU, 

so am trying to read AB Phase Voltage from PM2100 Schneider power meter, through rs485/usb with my PC with wincc rt v15.1, i am reading the data well except float 32, it is displayed as ####.

so i can read/write int16, means no problem with communication, it is conversion issue as i understand.

any suggestion plz

regards

Loret

Thank you Sir

can you guide me how to swap them without PLC, i mean to works only in the wincc side.

thanks alot

Loret 

Dear All

I have search a lot in Google,  I didn't get solution

I have learn a lot in VBFunction that I don't know before,

But still stuck in converting IEEE754 to readable data.

any efforts to help me, Thankx alot

Loret

why

why no one assisting me?

my question is not clear?

why

Hello, if you could send me your high and low words in hex or dec format (like 5-6 examples) of the floating point registers i could try writing a script for you based on this excel file for conversion i found from schneider site.

I also found a conversion formula:

S: sign 
E: exponent
F: faction (also referred to as the mantissa or significand)

iee754num=(-1)^S * 2^(E [dec format]-127) * (1.F)[Base 10]

Ok after working on it on my own despite you not answering i ve come up with these 3 scripts that will turn your value to real format readable by wincc prof probably. You need to have your 2 registers for floating value set as integers And you add the convert to real function on value change of either of the tags.The conv_to_real function has as inputs your HSW and LSW of your registers.I am waiting for your feedback on if it worked.

B11 is your value in Real format that is readable in WinCC Prof so if you make B11 show on an internal tag of your wincc you will get the proper real value shown.

Code:

Dear Sir

Thank you for replying,I have try many converters to have float or swapped float,I got very good practice using excel sheet, also the one you attached, my problem now with Vb script with wincc, I don't know even how to extract the LSW & MSW.

I check with modbus poll, I can get easily the LSW & MSW. like 17361 as MSW, and 36243 as LSW

which referred to 419.1060486 volt.

In Wincc I cant even capture the value to copy it to you here, it is showing me random big number, changing fast, it is in output text box, DOUBLE data type, and the display format in decimal, the address is 4x403020.

anyway I download your txt code, i will try to understand it and test, and if have new idea plz tell me.

kind regards

Loret