In our system, each discrete input has four states i.e. normal, reverse, flashing ane free. We encoded them as normal-00, reverse-01, flashing-10, and free-11.for this we require 2 bits. But coil function code in public function codes is packed as one bit per coil. Can we use these public function codes (standard coil function codes) or do we have to go for user defined function codes?

Please suggest us.

-Jignesh Mehta
[email protected]
HBLNife Power System Ltd.
Hyderabad
INDIA.

 

Why not use two sequential bits? Are you concerned with Modbus communication, ladder logic code, or something else?