Ladder logic isn't "sent" to the vfd, or anything else for that matter. It merely determines when certain PLC outputs are on depending on the PLC inputs and the recipe inside it.

if ladder logic can not sent to vfd then what is option to send all start stop and freq comand mode signal to vfd by rs485 port . if slc 5/03 and net AIC adopter and vfd and rj 45 connecter .

any massege comand is given by slc 5/03 allen bradely plc .

You can talk to the Flex from the 5/03. It's not that difficult. Refer to appendix c in the flex4 book for the 06 registers and bits to write.

If you have a long run between the PLC and the drive (stay within 4000ft) or you have multiple drives to control then use the df1 capability.

Don't try to be fancy if you just have a simple drive to run. You're usually much better off just using an analog output card for your 0-10v speed ref and a few outputs. Real simple logic there.

Here's an example that should help though:

http://forums.mrplc.com/index.php?s=431d5fef782cb4adfcc5c4430ddda99e&showtopic=17165