Eurotherm 605 Series, Product Manual Installation & Instructions

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6-48
Programming Your Application
605 Series Frequency Inverter
Functional Description
Kp(1+sTi)(1+sTd)
sTi(1+sTf)
D TIME CONST
I TIME CONST
P GAIN
ENABLE
INTEGRAL DEFEAT
X
PID OUTPUT
OUTPUT NEG LIMIT
OUTPUT POS LIMIT OUTPUT SCALING
SETPOINT
FEEDBACK
SETPOINT NEGATE
FEEDBACK NEGATE
+100.00%
-100.00%
PID ERROR
sign change
sign change
For an application that requires closed loop control, the error term may be derived from the
setpoint and feedback using a value function block. This error term is then used by the PID. The
output of the PID may be used to trim the demand setpoint via the SPEED TRIM parameter in
the REFERENCE function block.
D TIME CONST Range: 0.000 to 10.000 s
The derivative time constant of the PID controller.
FILTER TC Range: 0.000 to 10.000 s
In order to help attenuate high frequency noise on the PID output, a first order output filter has
been provided. This parameter determines the output filter time constant.
OUTPUT POS LIMIT
Range: 0.00 to 105.00 %
This parameter determines the maximum positive excursion (Limit) of the PID output.
OUTPUT NEG LIMIT Range: -105.00 to 0.00 %
This parameter determines the maximum negative excursion (Limit) of the PID output.
OUTPUT SCALING Range: -3.0000 to 3.0000
This parameter represents an overall scaling factor which is applied after the PID positive and
negative limit clamps.
PID OUTPUT Range: xxx.xx %
The output of the PID function.
PID ERROR Range: xxx.xx %
The result of SETPOINT - FEEDBACK, clamped to between
±
100.00%.