Siemens MICROMASTER 411 - Manual (Page 122)

10 Engineering Information Issue 03/01
MICROMASTER 411 & COMBIMASTER 411 Operating Instructions
122 6SE6400-5CA00-0BP0
10.2.2.3 Setting up the PI controller
Aufrufen der Parameter für den PI-Regler
The PI parameters are in the range between P2200 and P2294. For most
applications, the level 2 parameters are sufficient for setting up the PI controller. To
access only the PI controller parameters, you can use the parameter filter as
follows:
P0003 = 2
P0004 = 22
Enabling PI control
PI control is enabled using parameter P2200. For constant enabling of the PI
controller this should be set to 1. It is also possible to use a digital input (or other
BiCo functions) to enable the PI controller, e.g. the PI controller can be enabled
using DIN 2 by setting P0702 = 99 and P2200 = 722.1. This allows the user to
switch between frequency control and PI control when the inverter is not running.
PI Feedback signal
PI control requires a feedback signal from the process to monitor how the system is
behaving. For the majority of applications, this will be in the form of an analogue
sensor.
The MICROMASTER 411/COMBIMASTER 411 has one analogue input, terminal
connections 6 & 7, and the feedback signal can be connected to this input. The
source of the PI feedback signal must then be defined using P2264 = 755 (source
of PI feedback = analogue input 1). If required the analogue input can be scaled
using parameters P0757 – P0760. If a different source of feedback signal is used
(e.g. USS), P2264 must be set appropriately. The value of the feedback signal can
be viewed via parameter r2266.
The relation between the sensor signal and the manner in which the PI controller
changes the motor frequency must also be defined at this point. This is done using
P2271 (PI transducer type). There are 2 possible settings for this parameter, 0 and
1. The difference between these settings is whether the PI controller increases or
decreases output frequency as a response to a positive error signal (i.e. where the
feedback signal is less than the setpoint). The parameter description for P2271
describes in detail how to determine which setting is correct for your application.