Functions 
  5.2 Inverter control 
Frequency inverter  
Operating Instructions, 08.10. 2008, t.b.d. 
91 
5.2.6  Three-wire control, method 2 
Function description 
●  The first control command is a permanent enable signal for starting the motor. When this 
enable signal is canceled, the motor stops. 
●  The motor is started with the positive edge of the second control command. 
●  The third control command defines the direction of rotation. 
R 
R
R
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Figure 5-6  Three-wire control using digital inputs, method 2 
Table 5- 10  Function table 
Enable 
signal 
Motor 
ON 
Reverse 
motor 
Function when motor is at a 
standstill 
Function when motor is 
rotating 
0  Not 
relevant 
Not relevant  No effect  OFF1: The motor decelerates 
to a standstill 
1  0→1  0  The motor accelerates to the 
setpoint. 
No effect 
1  0→1  1  The motor accelerates to the 
inverted setpoint. 
No effect 
1  0  1→0  No effect  The motor reverses to the 
setpoint. 
1  0  0→1  No effect  The motor reverses to the 
inverted setpoint.