IEE754 to Decimal Conversion in AB

Hello folks,

Need a little help. I got to convert 32 bit floating point data in IEEE 754 format to Allen Baradley SLC floating point(F8:0).

FYI,

Decimal IEEE 754
7.5 40F00000 (hex)
0100 0000 1111 0000 0000 0000 0000 0000 (32 bit binary)

Now I need to write a block to convert 40F00000 to 7.5 .

The URL below gives a quick insight but I still don't have the generalise formula.......
http://babbage.cs.qc.edu/courses/cs341/IEEE-754.html


Thanks.

Technically, convert is the wrong term here. The AB PLC floats are already IEEE-754 floats. You need to find a way top get the bytes into the float element.

I'm assuming you have this value as either a double integer somewhere or two consecuting 16-bit integers. The latter case is pretty easy. Use the COP (copy) command with the lower address integer as the source, the float element as the destination and a length of one.

If you have it as a double somewhere you will need to figure out how to get it into two consecutive integers in order to use the COP.

Keith

That was really usefule. AB float is in IEEE 754 format indeed !!

Thank you eveybody.