Experimental Physics and
Industrial Control System

Hey Kevin,

I had the same problem once with a HV power supply.
I solved the problem this way:

- Read the value via StreamDevice into a longin record
- Use a sub-record to convert 32bit-int to 32bit-float

The subroutine is quiet easy:

union ficonv{
  float float_val;
  unsigned int  int_val;
};

static long intToFloat(subRecord *prec) {
  union ficonv myconf;
myconf.int_val = prec->a;
prec->b = myconf.float_val;
return 0;
}

I hope this helps!

Cheers
Florian

On 03/10/2016 05:28 PM, Kevin Peterson wrote:

I have a helium sensor that responds to a query with this reply:

   :80gv<VVVVVVVV><FFFFFFFF><CCCC><cr>

Where the non-constant parts of the response are ASCII hex characters
representing the following values:

   <VVVVVVVV> = (32 bit floating point) The current gas value
   <FFFFFFFF> = (32 bit unsigned integer) The sensor status
   <CCCC> = (16 bit unsigned integer) The message checksum

Is there a straightforward way to parse the floating point value using
StreamDevice format converters?

The raw double converter %R doesn't work, presumably because it is
interpreting the ASCII chars as bytes, rather than hex values.

The value can be read as an int with %08X, but it isn't obvious how to
then cast that value as a float.

Thanks,

Kevin

--
----------------------------------------
| Dr. Florian Feldbauer                |
|                                      |
| Helmholtz-Institut Mainz /           |
| Johannes Gutenberg-Universität Mainz |
| Johann-Joachim-Becher-Weg 36         |
| D-55128 Mainz                        |
|                                      |
| Office: SB1 / 00-213                 |
| Phone:  (+49)6131 / 39-29608         |
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