convert hex to float

[dmourer]

I have to convert a bit Hex string into a float. I built a vi from the following C code, but it only works on positive numbers. Any suggestions?

sample16 = (short) ((MSB << 😎 | LSB);

sample = (float)sample16/32768.0;

sample*=10.0;

[devchander]

You have a ready function in LabVIEW to do that.

Look at attached pic to find it

[altenbach]

Bytes are not "negative" or "positive". Do you have some more information on your conversion? Where is the sign bit?

I also assume that your MSB and LSB are originally U8. If it is just a 2byte string, feed it directly into the typecast function.

Maybe something along the lines of the attached modification will do the trick. If not, provide some sample inputs and the expected result.

[dmourer]

Your vi works. Thank you

[Hong.Zhang@agresearch.co.]

Dear

I am trying to convert 4 bit Hex string to floating number. Dut it does not work. 

Please help.

Thanks

[crossrulz]

Do you have a set definition of how the float is constructed?

[Hong.Zhang@agresearch.co.]

Thanks Crossrulz

How to set definitions?

Thanks

Hong

[altenbach]

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Hong.Zhang@agresearch.co.nz wrote:

How to set definitions?

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He is asking you for documentation of the format.

You strings don't conform to the IEEE 754 definition of SGL (big or little endian).

What device is generating the hex string? Do you have a manual?

[Hong.Zhang@agresearch.co.]

Hi altenbach

The data is come from flowmeter by MODBUS. 

Thanks

Hong

[crossrulz]

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Hong.Zhang@agresearch.co. wrote:

Hi @altenbach

The data is come from flowmeter by MODBUS. 

Thanks

Hong

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You are not giving us any useful information.  Look up the manual of your device.  Somewhere in there should be a definition of how the numbers are built up.