RoboteQ AX1500, AX2550 Connecting Tachometer to Analog Inputs, Ana Ana2 Operating Mode Pin

Connecting Tachometer to Analog Inputs

Connecting the potentiometer to the controller is as simple as shown in the diagram on Figure 28.

+5V 14

Ana 1: 11

Ana 2: 10

Ana 3: 12

Ana 4: 8

10kOhm

Ground 5

FIGURE 28. Potentiometer wiring in Position mode

Internal Resistors and Converter

47kOhm

A/D 10kOhm

47kOhm

The potentiometer must be attached to the motor frame so that its body does not move in relationship with the motor. The potentiometer axle must be firmly connected to the gear box output shaft. The gearbox must be as tight as possible so that rotation of the motor translates into direct changes to the potentiometers, without slack, at the gearbox’s out- put.

TABLE 9. Analog Position Sensor connection depending on operating mode

	Ana 1	Ana2	Ana 3	Ana 4
Operating Mode	pin 11	pin 10	pin 12	pin 8
RC or RS232 - Dual Channel	Position 1	Position 2	Unused	Unused
Analog - Dual Channel	Command 1	Command 2	Position 1	Position 2
RC or RS232 - Single Channel	Position	Unused	Unused	Unused
RC or RS232 - Dual Channel	Command	Unused	Position	Unused

See “Closed Loop Position Mode” on page 81 for complete details on Position Mode wir- ing and operation.

Important Warning

Beware that the wrong + and - polarity on the potentiometer will cause the motor to turn in the wrong direction and not stop. The best method to figure out the right potentiometer is try one way and change the polarity if incorrect. Note that while you are doing these tests, the potentiometer must be loosely attached to the motor’s axle so that it will not be forced and broken by the motor’s uncontrolled rotation in case it was wired wrong.

Connecting Tachometer to Analog Inputs

When operating in closed loop speed mode, tachometers must be connected to the con- troller to report the measured motor speed. The tachometer can be a good quality brushed DC motor used as a generator. The tachometer shaft must be directly tied to that of the motor with the least possible slack.

AX1500 Motor Controller User’s Manual 59