Sonic Alert DCP301 user manual Parameter Setup

Chapter 7. PARAMETER SETUP

No.	Item Code	Item	Factory	User						Setting
			Setting	Setting
21	P -3	Proportional band	100.0		•	When variable parameter 2 P 1 D setting is 1 (2
		(PID set 3)				degrees of freedom PID enabled), the parameter (P, 1,
22	1 -3	Reset time	0			D) ideal for control when SP changes and the param-
		(PID set 3)				eter (D P, D 1, D D) ideal for inhibiting disturbance
23	D -3	Rate time	0			during settling are automatically switched.
		(PID set 3)
24	O L -3	MV lower limit	0.0		•	Decreasing the proportional band (P, D P) value
		(PID set 3)				improves controllability. However, it also makes
25	O H -3	MV upper limit	100.0			overshoot or hunting more likely to occur.
		(PID set 3)				Use of the controller on a motor or actuator shortens
26	R E -3	Manual reset	50.0
						the controller’s life. Do not set the proportional band
		(PID set 3)				(P, D P) to too small a value.
27	B R -3	Brake	0
		(PID set 3)			•	Decreasing the reset time (1, D 1) improves trackability.
28	D P -3	Disturbance inhibit	100.0			However, it also makes cycling caused by integrating
		proportional band				action more likely to occur.
		(PID set 3)
						When 1 setting is 0, integrating operation for inhibiting
29	D I -3	Disturbance inhibit	120			disturbance also functions.
		reset time
		(PID set 3)			•	Increasing the rate time (D, D D) allows overshoot to
30	D D -3	Disturbance inhibit	0			be inhibited more easily. However, it also make
		rate time				hunting more likely to occur as the controller reacts to
		(PID set 3)				minute changes in PV.
31	P -4	Proportional band	100.0			In a temperature control system, setting the rate time
		(PID set 4)
						to 1/		to 1/		of the integrating time is generally consid-
32	1 -4	Reset time	0				3		4
						ered to be appropriate. In a pressure or flow rate
		(PID set 4)
						control system, derivative action causes hunting.
33	D -4	Rate time	0
						Either set the D setting to 0.0 to disable derivative
		(PID set 4)
						action, or decrease the setting so that derivative action
34	O L -4	MV lower limit	0.0
						is almost negligible. The latter solution is more
		(PID set 4)
						frequently adopted.
35	O H -4	MV upper limit	100.0
		(PID set 4)			•	The MV upper and lower limits (O L, O H) function as
36	R E -4	Manual reset	50.0
						integrating limits. When the MV reaches the upper or
		(PID set 4)
						lower limit, integration no longer functions. This
37	B R -4	Brake	0
						prevents reset wind-up that occurs when the PV has
		(PID set 4)
						not risen for a long time.
38	D P -4	Disturbance inhibit	100.0
		proportional band			•	Manual reset (R E) is a setting for eliminating offset
		(PID set 4)
						that occurs during proportional action (integrated
39	D 1 -4	Disturbance inhibit	120
						action disabled). For manual reset, set the MV ideal for
		reset time
						deviation 0.
		(PID set 4)
40	D D -4	Disturbance inhibit	0		•	Increasing the brake (B R) value increases the
		rate time				overshoot inhibit effect. However, it also lengthens the
		(PID set 4)				rise time.

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