Pack 2 Bytes into 1 Word Micrologix 1500LRP

[ddnnis]

I am working on an RFID project that will write Micrologic integer value to an RFID tag. The RFID system is the Turck BLCDN RFID SLICE. It communicates via Devicenet. I have mapped it to the scanner and all works well. It will allow me to write and read 4 words with no issues. The problem is that I need to write and read at 5 values. Two of the word values are under (255 decimal, hence 1 BYTE). If I could pack these 2 values as one word I believe this would solve my issue. Long story short can anyone help me on how to pack 2 Byte's into 1 Word on the Micrologix 1500LRP. I will also need to unpack them when I read the RFID tag.
Any help would be much appreciated.
Thanks

 

[kolyur]

One approach would be to use the SWP instruction to swap the low and high bytes of one of the words, which would put the 8 data bits on the high end and 8 zeros on the low end. Then use a masked move MVM or OR instruction to combine the swapped word with the remaining value, and you'd have two 8-bit values stored in one 16-bit word. I've never personally used the SWP instruction but after reading the help file it seems like it should work.

 

[allentcm]

Here is a working example.

 

[ddnnis]

Thanks, Ill try it the morning.