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Analog Inputs (Specific Interface Requirements)
The analog input channel is a differential input amplifier to allow controllers that have
differential output drivers a three wire connection that excludes potential ground loops. When
differential modes of operation are used, the command input is based on 5 volts equaling
maximum input and the analog ground from the external controller must be connected to the
MPA drives GND connection. A +5 volt connection to the COM+ terminal and a -5 volt
connection to the COM- terminal is equal to a +10 command voltage. This is what a
differential input is and an analog GND connection is required. The rotational direction of the
motor will be CW viewed from the shaft end of the motor. To change directional rotation the
COM+ and COM- connections must be reversed.
3
CMD
+
1
2
–
The most typical input to the command input is a simple two wire interface consisting of a
command voltage with respect to a GND. The GND potential must be connected to the MPA
GND connection associated with the analog channel and the command voltage can be
connected to either the COM+ or COM- input to determine the rotational characteristic
required. A positive command voltage with respect to GND connected to the COM+ terminal
will cause CW rotation as viewed from the shaft end of the motor. The unused input, COM+
or COM-, should be connected to GND.
3
CMD
+
1
2
–
MPA AMPLIFIER
GND
COM–
COM+
MPA AMPLIFIER
GND
COM–
COM+
14
1
13
12
11
GND
10
–
9
1
+
8
7
6
5
TYPICAL EXTERNAL CONTROLLER
4
WITH DIFFERENTIAL DRIVERS
3
2
1
MPA AMPLIFIER
I/O AND ANALOG INPUTS
14
13
12
11
GND
10
–
9
1
+
8
7
6
5
4
MOST COMMON EXTERNAL CONTROLLER
3
WITH SINGLE ENDED DRIVER
2
1
MPA AMPLIFIER
I/O AND ANALOG INPUTS
3
+
COMMAND
2
–
3
+
2
–
COMMAND
3
+
2
–
15
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