Siemens SINAMICS G110, Operating Instructions Manual

Page: 58 / 92

Using the SINAMICS G110 04/2005
SINAMICS G110 Operating Instructions
58
6SL3298-0AA11-0BP0
4.3.2 2-wire Logic (P0727=1)
Overview
This method uses two maintained signals, ON_FWD and ON_REV which start/stop
the drive and determine the direction of the motor.
The advantage of this method of control is that ON_FWD and ON_REV can be
switched at any time, independently of the setpoint or frequency output or direction
of rotation, and there is no requirement of the motor to ramp-down to 0 Hz before
the command is performed.
Function
The following description refers to Figure 4-3.
With ON_FWD closed and maintained closed the drive is ON and runs in forward
direction.
Applying only ON_REV (and keeping the contact closed) the drive is ON and runs
in reverse direction.
If both signals are however enabled (contacts are closed) the drive will perform an
OFF1 and ramp down to a stop.
If both signals are disabled the drive is in OFF1 state.
o
Equivalent Control Inputs
Time
Control
Commands
ON_FWD
ON_REV
Active
Active
ON_FWD
ON_REV
K1
K2
ON_FWD
ON_REV
ON_FWD
ON_REV
Act. Act. Act.
Active
o
o
o o
o = OFF1
Inverter
Frequency
f out
Figure 4-3 2-wire control using ON_FWD and ON_REV