AB uLogix PID Loop vs Yokogawa UT350 PID


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We have been using Yokogawa UT350 Controllers & AB 1200 Micrologix PLC in some of our applications.

UT320 PID controller give an perfect control.
Whereas the PLC isn't so precise as far as the output is concerned.

What we observed was: In UT320 say the maximum o/p is attained when the Procees value (PV) is > Set point (SP), then upon slight decrease in the Process even the o/p reduces very gradually.

But for the same above case, in the micrologix PLC the output starts reducing only when the Process value becomes equal to Setpoint. So some times more or less the PLC is becoming an On/Off controller. As far as the tuning is concerned, the PLC is tuned for the best performnace, but still we face the above difficulty.

Can any one help me?