Determination Of The Required Control Performance Of The Cu320-2 Control Unit - Siemens SINAMICS G130 Engineering Manual

6.2.4

Determination of the required control performance of the CU320-2 Control Unit

The CU320-2 Control Unit has been designed to control multiple drives and provides the communication, open-loop
and closed-loop control functions for the Line Module and one or more Motor Modules or axes.
The load on the CU320-2 Control Unit depends on the number of Motor Modules (axes), the control mode required
by the application (servo control, vector control, V/f control) and the dynamic response requirements of the selected
control mode (current controller clock cycle). The faster the dynamic response (i.e. the shorter the current controller
clock cycle) the greater the load on the Control Unit.
The hardware components and functions listed below also increase the load on the CU320-2 Control Unit:
·
Communication boards in the option slot of the CU320-2 (e.g. CBC10, CBE20, TB30),
·
TM31 Terminal Modules with fast sampling rates (250 μs),
·
Extended safety functions (SS2, SOS, SSM, SLS),
·
DCC blocks,
·
Basic positioner (EPos).
The examples below provide an initial rough guide to potential maximum configurations on a CU320-2 Control Unit
(including performance expansion, see below). The reliability of complex configurations can be checked with the
"SIZER for Siemens Drives" configuring tool.
Examples with servo control and a current controller clock cycle of 125 μs or 250 μs:
·
6 servo axes (125 μs) + 2 EPos + 2 extended safety functions
·
5 servo axes (125 μs) + 5 EPos + 5 extended safety functions
·
6 servo axes (250 μs) + 6 EPos + 6 extended safety functions + 100 DCC blocks (2 ms)
Examples with vector control and a current controller clock cycle of 500 μs::
·
6 vector axes (500 μs) + 50 DCC blocks (2 ms)
·
4 vector axes (500 μs) + 50 DCC blocks (2 ms) + 2 DCC-based winders (4 ms)
Examples with V/f control and a current controller clock cycle of 500 μs:
·
12 V/f axes (500 μs) + 50 DCC blocks (2 ms)
·
10 V/f axes (500 μs) + 100 DCC blocks (2 ms) + 2 extended safety functions
The information specified for each of the examples already allows for the internal communication required between
the drive objects and the control of the Active Infeed, Smart Infeed or Basic Infeed which supplies the Motor Modules
(axes).
Licensing of the CU320-2 Control Unit according to the number of axes with performance expansion
The load on the CU320-2 increases with the number of Motor Modules or axes and the required dynamic response
(short current controller clock cycle). For this reason, the performance expansion is required when the drive
configuration includes more than a particular number of Motor Modules or axes. The performance expansion is a
firmware option which is subject to license. With regard to the CU320-2, it is a purely axis-related option and thus the
actual utilization of the CU320-2 Control Unit for an individual application is irrelevant as regards the selection of the
performance expansion option.
The performance expansion which is subject to license is thus basically required
·
with 4 Motor Modules or more operating in servo control mode,
·
with 4 Motor Modules or more operating in vector control mode,
·
with 7 Motor Modules or more operating in V/f control mode.
For firmware version 4.3, the table below provides an overview of the maximum possible number of Motor Modules or
axes on one CU320-2 Control Unit as a function of control mode and current controller clock cycle, but ignoring
supplementary hardware components or functions such as Extended Safety Functions or DCC.
Engineering Information
SINAMICS Engineering Manual – November 2015
SINAMICS S120
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