Manual Tuning - Brainchild P41 User Manual

Auto-Tuning Error Auto-Tuning Error
If auto-tuning fails an ATER message will appear on the upper display If auto-tuning fails an ATER message will appear on the upper display
in cases of : in cases of :
If PB exceeds 9000 ( 9000 PU, 900.0 F or 500.0 C ). If PB exceeds 9000 ( 9000 PU, 900.0 F or 500.0 C ).
or if TI exceeds 3600 seconds. or if TI exceeds 3600 seconds.
or if set point is changed during auto-tuning procedure. or if set point is changed during auto-tuning procedure.
Solutions to Solutions to
1. Try auto-tuning once again. 1. Try auto-tuning once again.
2. Don't change set point value during auto-tuning procedure. 2. Don't change set point value during auto-tuning procedure.
3. Don't set zero value for PB and TI. 3. Don't set zero value for PB and TI.
4. Use manual tuning instead of auto-tuning. ( See section 3-12 ). 4. Use manual tuning instead of auto-tuning. ( See section 3-12 ).
5. Touch 5. Touch and and

3 - 11 Manual Tuning

3 - 11 Manual Tuning
In certain applications ( very few ) using auto-tuning to tune a process In certain applications ( very few ) using auto-tuning to tune a process
may be inadequate for the control requirement, then you can try may be inadequate for the control requirement, then you can try
manual tuning. manual tuning.
If the control performance by using auto- tuning is still unsatisfactory, If the control performance by using auto- tuning is still unsatisfactory,
the following rules can be applied for further adjustment of PID values : the following rules can be applied for further adjustment of PID values :
ADJUSTMENT SEQUENCE ADJUSTMENT SEQUENCE
(1) Proportional Band ( PB ) (1) Proportional Band ( PB )
(2) Integral Time ( TI ) (2) Integral Time ( TI )
(3) Derivative Time ( TD ) (3) Derivative Time ( TD )
Figure 3.11 shows the effects of PID adjustment on process response. Figure 3.11 shows the effects of PID adjustment on process response.
60
key to reset key to reset
SYMPTOM
Slow Response Slow Response
High overshoot or High overshoot or
Oscillations Oscillations
Slow Response Slow Response
Instability or Instability or
Oscillations Oscillations
Slow Response or Slow Response or
Oscillations Oscillations
High Overshoot High Overshoot
Table 3.4 PID Adjustment Guide Table 3.4 PID Adjustment Guide
UM0P411A
L L L L
message. message.
SOLUTION
Decrease PB Decrease PB
Increase PB Increase PB
Decrease TI Decrease TI
Increase TI Increase TI
Decrease TD Decrease TD
Increase TD Increase TD