Description of the individual parameters

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Controller parameters

Portrayed in LOGO!

Possible value range in the LOGO!

Mn
Manipulated variable at the time n

Output of the PI controller block

0 to 1,000

kP
Gain of the P part

 

kI
Gain of the I part

In the LOGO!, the parameter KC applies as an increase for the I part and the P part of the controller equally.

Should you enter KC=0, then the P part of the controller switches off. In this special case, k is automatically set to 1 for the I part.
If KC = 0: kP = 0 and kI = 1

If KC <> 0: kP = kI = KC

0.00 to 99.99

TS Sampling time, duration of a time slice

Fixed

500 ms

TI
Integral time

Parameter TI, if you set this parameter to 99:59 min, then you switch off the I part of the controller.

00:01 min to 99.59 min

en
Loop error at the time n; generally applies:
e = SP – PV

Refer to SP and PV

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SP

The parameter SP is the set-value assignment w. For this parameter you can use the analog output of a different special function.

-10,000 to +20,000

PV

PV is the process value x and is calculated as follows:

PV = (analog value on input * gain) + offset.

You can connect the input for example by means of an analog input with a PT100 sensor.

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The gain parameter has an effect on PV

0.0 to 10.0

 

The offset parameter has an effect on PV

-10,000 to +20,000

 

PV is restricted by the parameters Min. and Max.

In each case:
-10
,000 to +20,000

 

The Dir parameter gives the action direction of the controller.

Positive means: If set value > process value then the process value is increased; if set value < process value then the process value is reduced.

Negative means: If set value > process value then the process value is reduced; if set value < process value then the process value is increased.

e.g. heat regulation: if the set value is greater than the process value (room is too cold), the manipulated variable increases the process value.

- or +

 

Refer to the PI controllers - description of special function for more details (for example, switching from manual to automatic mode, parameter sets, etc.).