Allen-Bradley Logix5000 Reference Manual page 497

Special Instructions (FBC, DDT, DTR, PID) Chapter 13
Condition Relay Ladder Action
Rung-condition-in is false.
Compare.EN bit is cleared.
Compare.FD bit is cleared.
Compare.DN = 0
Examine
compare.DN bit.
Compare.DN = 1
Compare DN bit is cleared.
Compare.POS value is cleared.
Result.DN bit is cleared.
Result.POS value is cleared.
Rung-condition-out is set
to false.
End
Rockwell Automation Publication 1756-RM003N-EN-P - October 2011 497