Siemens SIPART DR21, Manual

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2 Technical Description
2.2 Range of Application
Manual
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SIPART DR21
C73000-B7476-C143-08
D
Subject to modifications
The user’s guide has been compiled with great care. However, it may be necessary, within
the scope of product care, to make changes to the product and its operation without prior
notice which are not contained in this user’s guide. We are not liable for any costs ensuing
for this reason.
2.2 Range of Application
D
Application
The SIPART DR21 process controller is a digital instrument of the mid to upper performance
class. It is used in control systems in process engineering for instance in the chemical and
petrochemical industries, control- and power station engineering and in other fields of in-
dustry such as the food- and drink and tobacco industries.
The controller’s great flexibility makes it suitable for use in simple or intermeshed control cir-
cuits. The wide setting range of the control parameters allow the SIPART DR21 to be used
in process engineering both for fast (e.g. flow) and slow controlled systems (e.g. tempera-
ture). The controller determines the optimum control parameters independently on request
without the user being expected to have any prior knowledge of how the control loop may
respond. The applied adaptation procedure is suitable for systems with compensation and
aperiodic transient behavior; Even greater dead times are taken into account. (Systems with-
out compensation cannot be adapted by this method.)
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Controlling tasks
The input structure of the SIPART DR21 controller can be changed by configuring in such a
way that the following controlling tasks can be solved.
- Fixed value controls, even with disturbance variables applied at the input
- Three-component controls
- Control circuits with up to two internal setpoints
- Follow-up-/synchronization controls
- Disturbance variables applied at the output
- Computer-controlled circuits in SPC- or DDC-operation
- Ratio controls with fixed or manipulated variables
SIPART DR21 can also be configured as a control unit, manual control unit, process display
or resolver transmitter.
The SIPART DR21 controller can be used as a continuous controller with output 0/4 to
20 mA, as a stepper controller with a built-in relay for controlling motorized drives or as a
two-position controller for heating/cooling systems.
Overlaid control functions or status- and alarm messages are possible through digital inputs-
and outputs.