Eaton EASY-E4 Series User Manual

6. Function blocks
6.1 Manufacturer function blocks
6.1.4 Open-loop and closed-loop function blocks
6.1.4.1 DC - PID controller
General
easyE4 The base devices provide 32 PID controller function blocks
DC01...DC32.
Operating principle
A closed-loop control circuit with a PID controller consists of the following com-
ponents:
l Setpoint (reference variable),
l Actual value (controlled variable),
l System deviation = (setpoint–actual value),
l PID controller,
l Control system (e.g. PTn system),
l Disturbance variables.
The PID controller operates on the basis of the equation of the PID algorithm. According
to this, the manipulated variable Y(t) is the result of the calculation of the proportional
component, an integral component and a differential component.
PID controller equation:
Y(t) = YP(t) + YI(t) + YD(t)
Y(t)=
calculated manipulated variable with scan time t
YP(t)=
Value of the proportional component of the manip-
ulated variable with scan time t
YI(t) =
Value of the integral component of the manipulated
variable with scan time t
YD(t)=
Value of the differential component of the manip-
ulated variable with scan time t
Proportional component
The proportional component YP is the product of the gain (Kp) and the control difference
(e). The control difference is the difference between the setpoint (Xs) and the actual
value (Xi) at a specified scan time. The equation used by the device for the proportional
component is as follows:
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easyE4 11/18 MN050009 EN www.eaton.com

Eaton EASY-E4 Series Specifications

General

Type	Programmable Relay
Digital Inputs	Up to 12
Digital Outputs	Up to 8
Display	LCD
Operating Temperature	-25°C to +55°C
Protection Degree	IP20
Storage Temperature	-40°C to +70°C
Supply Voltage	24 V DC, 100-240 V AC
Analog Inputs	4
Outputs	Relay, transistor
Programming	EASY-SOFT-PRO
Communication	Ethernet, Modbus, CANopen
Expansion	Expandable with additional modules
Relative Humidity	5% to 95% (non-condensing)
Standards	IEC/EN 61131-2, UL 508, CSA C22.2 No. 142