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4 Functional Description
4.4 Enhanced operating modes
4.4.5 Voltage regulator mode
If the drive is to operate as a pure voltage regulator, this can be configured with VOLTMOD. The mo-
tor voltage is then output proportionally to the default value. The current limitation remains active.
With this mode, it is possible to use a higher level regulator. The controller then serves only as a
power amplifier.
Command Function
Description
VOLTMOD Set Voltage Mode
Activate Voltage Regulator Mode
U
Set Output Voltage
Output motor voltage (corresponds to -Uv…+Uv)
with SOR0 only
Value: -32 767…32 767
Three types of operation exist for specifying the target value for the output voltage: RS232 Inter-
face, voltage at the analog input and PWM signal at the analog input.
SOR0 must be set in for the RSS232 interface to be used for specifying the speed.
The command U sets the output voltage proportional to the supply voltage. A value of 32 767 passes
the full power supply voltage to the motor. A value of 0 passes 0 V to the motor. A value of –32 767
passes the full power supply voltage inverted.
SOR1 must be set first if a voltage is to be used at the analog input to specify the speed.
The analog input voltage sets the output voltage scaled to the operating voltage. With a voltage of
10 V, the full power supply voltage is passed to the motor. A value of 0 V passes 0 V to the motor. A
value of –10 V passes the full power supply voltage inverted.
Using a PWM signal to specify the speed requires setting SOR2 first.
A 100 % duty cycle passes the full power supply voltage to the motor. A 50 % duty cycle passes 0 V
to the motor. A 0 % duty cycle passes the full power supply voltage inverted.
4.4.6 Analog target current presetting
You can switch to analog target current presetting with the SOR3 command. The limitation current
is then proportional to the voltage at the analog input, and the internal I²t current limitation is
deactivated. The set current is weighted with the maximum current LPC.
If 10 V are present at the analog input, the current is accordingly limited to the maximum current
set with LPC. Even if negative voltages are present at the analog input, the current is limited to the
amount of the applied voltage. Negative target current presettings therefore have no effect on the
direction of rotation!
4.4.7 IxR control for DC controllers
For speed-controlled applications with DC motors without an encoder, an IxR control is available on
the MCDC. In this mode, the motor speed is determined via an internal motor model. Consequently,
the encoder and the associated wiring can be omitted. However, control quality and accuracy are
considerably restricted. This mode is mainly suited for higher speeds and larger motors in the
FAULHABER range.
Command Function
Description
IXRMOD
Set IxR Mode
Activate IxR control (MCDC only)
RM
Load Motor Resistance
Load motor resistance R
M
in accordance with infor-
mation in the data sheet. Unit: m
KN
Load Speed Constant
Load speed constant k
n
in accordance with informa-
tion in the data sheet. Unit: rpm/V
