Inverter Control; Frequency Inverter Control Using Digital Inputs (Two/Three-Wire Control) - Siemens Sinamics G120 CU240E Operating Instructions Manual

5.2

Inverter control

5.2.1

Frequency inverter control using digital inputs (two/three-wire control)

Configuring start, stop and direction of rotation reversal using digital inputs
If the frequency inverter is controlled using digital inputs, using parameter P0727, you can
define how the motor responds when it is started, stopped, and the direction of rotation is
changed (reversing).
Five different methods are available for controlling the motor. Three of the five control
methods just require two control commands (two-wire control). The other two control
methods require three control commands (three-wire control).
The wide range of setting options is especially intended to be able to emulate existing control
methods on the plant or system side if the frequency inverter has to be integrated into an
existing application. The two most common methods use the factory setting (P0727 = 0) and
are available as standard in SINAMICS frequency inverters.
Note
When CW rotation is activated, the frequency inverter generates a CW voltage characteristic
at its output terminals. Whether the connected motor actually rotates CW depends on the
wiring between the frequency inverter and motor.
Factory setting for "start", "stop", and "direction reversal" control commands
In the factory setting (P0727 = 0), the motor is operated using two control commands. In this
case, two variants are available
Further methods for "start", "stop", and "direction reversal" control commands
Parameter P0727 offers three additional methods for controlling the motor.
● Method 3 for controlling the motor is ideal for drives where the direction of rotation is
● Two further methods are available for controlling motors, each of which use three control
Frequency inverter
Operating Instructions, 08.10. 2008, t.b.d.
manually changed, for instance, traction drives that are controlled from a master switch. It
is similar to method 2, but differs with respect to how the motor responds when both
control commands are present at the same time. In contrast to method 2, it also allows
you to change the direction of rotation at any time.
commands. With these methods, the motor is no longer controlled via the signal level
only but also with the positive signal edges of certain commands.
Just the same as method 3 of the two-wire control, the first three-wire control method is
especially suitable for drives where the direction of rotation is manually reversed.
Functions
5.2 Inverter control
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