2 Integers into 1 Float

[junkerjorg]

I am receiving data from a controller that is sending out floats or 32 bit words over devicenet to my 5/05 processor. The devicenet is mapped to M files which are 16 bit words. I need to map those two 16 bit M files back into a single floating point. I thought the COP instruction with a length of 2 would be wise enough to take M1:13.75 and M1:13.76 and copy it into F24:0 but it copies to F24:0 and F24:1. I'm sure there is an easy explanation but it is escaping my mind. Please help

 

[sthompson]

I am receiving data from a controller that is sending out floats or 32 bit words over devicenet to my 5/05 processor. The devicenet is mapped to M files which are 16 bit words. I need to map those two 16 bit M files back into a single floating point. I thought the COP instruction with a length of 2 would be wise enough to take M1:13.75 and M1:13.76 and copy it into F24:0 but it copies to F24:0 and F24:1. I'm sure there is an easy explanation but it is escaping my mind. Please help

The length in the Copy Instruction is the Destination Length. Did you perhaps use a length of two? The other issue is getting the Data into the Float in the right order. You might need to use a SWP Instruction or MVM Instructions to reassemble the Data in the right order.

Stu....

 

[junkerjorg]

I was afraid I might have to do a SWP.

 

[sthompson]

I was afraid I might have to do a SWP.

It can be fun, I have had to do this in a ControlLogix from a unit that was giving me the data as four SINTs. There was no information in the Manual about the order the SINTs came in, so I had to do it by trial and error.

The reason I mentioned the Lenth, is becasue you are moving two INTs to one Real/Float. So, you shouldn't have it going into two Floats with a proper lenght of one.

Stu...