Experimental Physics and
Industrial Control System

From: [email protected] <[email protected]> on behalf of Davis, Mark via Tech-talk <[email protected]>
Sent: Wednesday, June 5, 2019 4:01 PM
To: Brown, Garth; [email protected]
Subject: Re: StreamDevice for an odd float format

You can add your own format converters to StreamDevice.

John Priller ([email protected]) at our lab has written the code for several odd format like this (see attached code).  I believe the one you want is the %ZHF one.

Mark

Hi All,

I'm trying to use StreamDevice to talk to a device that is almost, but not quite, giving me data that the format converters (as I understand them) can convert.

It’s an ASCII representation of the IEEE 32 bit floating point format, e.g. the raw data for a value of 28.0 is

 

0x34 0x31 0x45 0x30 0x30 0x30 0x30 0x30

 

Which is the ASCII code for

 

41E00000

 

Which is the IEEE-754 floating point representation of 28.0.

I think that if the raw data were 0x41E00000, %R would be able to convert it. And if the raw data were

0x32 0x38 0x2E 0x30 (ASCII for 28.0)

then %f would be able to convert it.

Before I start writing calc records to convert the 32 bits to a float value, I figured I'd ask if someone had a less brute-force approach. Maybe a StreamDevice format converter trick I don't know about?

 

Thanks,

Garth