Micromod Micro-DCI: 53SL5100B Single Loop Controller - Manual (Page 79)

53SL5100B Single-Loop Controller
INSTRUCTION MANUAL
73
Table 10-1. Summary Information for Tuning Parameters
Abbreviation Datapoint Min Value Max Value Parameter
P.B. C106 2% 1000% Proportional Band
TR C107 0.02 minutes/rep. 200 minutes/rep. Reset
TD C108 0.01 minutes 8 minutes Rate
Table 10-2. Summary Information for Tuning Parameters
Step Procedure
1 Set the process to approximately normal conditions in Manual mode.
2
Set TR (C107) first to minimum value (0.02 minutes) for several moments, then set it to the extreme maximum
(200 minutes) to lock in a fixed reset value.
3 Set P.B. (C106) to the widest value (1000%).
4 Set TD (C108) to the lowest value (0.01 minutes).
5 Switch to Auto mode.
6 Slowly reduce P.B. (C106) until process cycling starts.
7 Increase TD (C108) slowly until process cycling stops.
8 Reduce P.B. (C106) until process cycling starts again.
9 Further increase TD (C108) until cycling stops again.
10 Repeat Steps 8 and 9 until no improvement can be made when TD is increased.
11 Increase P.B. (C106) to a safe margin approximately 1.5 times the value attained in Steps 8 through 10.
Table 10-3. Proportional Cycle Method
Step Procedure
1 Set the process to approximately normal conditions in Manual mode.
2
Set TR (C107) first to minimum value (0.02 minutes) for several moments, then set it to extreme maximum
(200 minutes) to lock in a fixed reset value.
3 Set P.B. (C106~ to the widest value 1000%).
4 Set TD (C108) to the lowest value (0.01 minutes).
5 Switch to Auto mode.
6 Slowly reduce P.B. (C106) until process cycling starts.
7
When a slight cycle is repeatedly established, measure the peak-to-peak period of oscillation and record it as
T minutes.
8 Observe the P.B. setting and record it as P.
9
Compute the best settings as follows: A. Proportional & Integral (PI): P.B. = 2 (P), T
R
= 0.8(T) B. Proportional
& Derivative (PD): P.B. = 0.8(P), T
D
= 0.12(T) C. Proportional, Integral, and Derivative (PID): P.B. = 1.5(P), T
R
= 0.5(T), T
D
= 0.12(T)
Table 10-4. Step Response Method
Step Procedure
1 Set the process to approximately normal conditions in Manual mode.
2
Introduce a 10% (approximate) step change to the manually regulated signal to the valve. Observe the
magnitude of the step in percent of full signal span F. Also plot a graph of the resulting transient curve traced
by the controlled variable.
3 Draw a straight line tangent to a point on the curve having the greatest slope (most linear).
4 Measure the apparent dead time L in minutes as shown in Figure 10-1.
5
Measure RL, the product of the slope and dead time as shown in Figure 10-1. This value should be expressed
in percent of full scale span.
6
Compute the best settings as follows: A. Proportional (P): P.B. = (100 RL)/ F. B. Proportional & Integral(PI):
P.B.= (100 RL)/ F, T
R
= 3L C. Proportional, Integral, and Derivative (PID): P.B.= (80 RL)/ F, T
R
= 2L, T
D
= 0.5L