Problem with D memory area

[lenar 0]

Hi All. I have a problem with D memory area. I have PLC CJ2M with ID211(DC input), ID211, OC211 (Relay output), OD212 (Transistor output) on the CPU rack. When I turn on all outputs in the OC211, all my datas in the D memory area is set to 0. What could be the problem? plc_project.zip Edited 15 Apr 2015 by lenar

[Michael Walsh 268]

It would have to be something in your code. Post it here and we can take a look. Are you using the BSET instruction? Are you doing anything with indirect addressing (*D, @D or IR)? Are you doing anything with the PUSH instruction? There is some potential that these could be doing what you are seeing.

[BITS N BYTES 66]

Don't read/speak Russian, but this is most likely the problem!

[Michael Walsh 268]

Yes, that is definitely it. Nice find Bits N Bytes. When you turn on all the bits in channel 2 (OC211), it sets the number of words to transfer in your instruction to 65,535, which of course wipes out the D area, starting at D0. I believe that you meant to transfer only two words. Try using XFER &2 2001 D0, instead. Using the number 2 without the & results in using the value in channel 2 as the size of the transfer.

[lenar 0]

Thanks for helping!