Sartorius DCU 3, Operator'S Handbook Manual

Page: 43 / 150

Operators Handbook DCU3 – System
6., Main function „Control Loops“
BAEDCU3 - Rev. 4.6 - 0504 6 - 9
6.6 Stirrer Speed Controller
The speed of the stirrer motor is controlled via an external, extra motor controller. You will adjust all
stirrer speed parameters at the DCU3 system. The control function of the DCU3 system works as a
setpoint controller and supplies the analog setpoint signal to the motor controller. Furthermore the
menu displays the stirrer speed signal delivered from the motor controller.
When the stirrer speed controller is switched to „off“, an additional digital output switches off the motor
contactor. If the fermentor is equipped with a pO
2
- controller the stirrer speed controller can be
switched as a servo controller in the pO
2
cascade control loop.
6.6.1 Operating Display
For a description of the tags, the physical units or entries, the displayed value or function
and of the required inputs see the table in section
6.3, Controller Operation in General.
6.6.2 Special Notes
In „manual“ mode, when entering the MIN/MAX output limits and entering data into OUT,
allways observe the permissible measuring range of the corresponding speed control:
– BIOSTAT
®
ED : 0 - 100 % = 0 - 1500 rpm
For further information on the permissible speed range of your fermentor check the preset
configuration of your DCU3 – system or refer to the configuration documentation of your fer-
mentor system delivered extra.
Basic stirrer speed and/or maximum permitted speed during operation as a servo controller
in pO
2
cascade control are entered via the MIN/MAX output limits.