Delta DVP-ES2/EX2/SS2/SA2/SX2/SE manual ⎢Et +

3. Instruction Set

2.When control mode (S3+4) is selected as K3 and K4:

y The equation is exclusively for temperature control will be modified as:

	1 ⎡		1 ⎛		1	⎞
MV =		⎢E(t) +		⎜ E(t)		⎟	+ K D
					S
	K P ⎣		K I ⎝			⎠
where	E(t) = SV(t)- PV(t)

*E(t)S ⎤⎥ ,

⎦

yControl diagram:

In diagram below, 1/KI and 1/KP refer to “divided by KI” and “divided by KP”. Because this mode is exclusively for temperature control, users have to use PID instruction together with GPWM instruction. See Application 3 for more details

PID operation is within dotted area

+

1/S	1/K I
	+	+
		1/KP	G(s)
		+
S	K D

yThis equation is exclusively designed for temperature control. Therefore, when the sampling time (TS) is set as 4 seconds (K400), the range of output value (MV) will be K0 ~ K4,000 and the cycle time of GPWM instruction used together has to be set as 4 seconds (K4000) as well.

yIf users have no idea on parameter adjustment, select K3 (auto-tuning). After all the parameters are adjusted (the control direction will be automatically set as K4), users can modify the parameters to better ones according to the adjusted results.

3.When control mode (S3+4) is selected as K10:

yS3+2 (KI) and S3+3 (KD) in this mode will be switched to parameter settings of Integral time constant (TI) and Derivative time constant (TD).

yWhen output value (MV) reaches the upper bound, the accumulated integral value will not increase. Also, when MV reaches the lower bound, the accumulated integral value will not decrease.

yThe equation for this mode will be modified as:

MV = KP ⋅ ⎢⎡E(t)+	1	∫ E(t)dt + TD	d	E(t)⎥⎤
	T		dt
⎣				⎦
	I

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