RoboteQ AX3500 user manual Wiring Optional Limit Switches, Important Warning

Connecting and Using the Encoder Function

Signal on Channel A or B

Quadrature Signal

Switch Detect Signal

FIGURE 52. Signals seen by encoder using multi-levels and limit switches

2.5V

0.5V

Important Warning

When a limit switch is activated, the encoder signal that is shared with the switch is no longer visible by the encoder module, and pulse counting and speed measure- ment stops.

Wiring Optional Limit Switches

If limit switches are needed by the application, additional circuitry is required in order to create a multi-level signal that shares the encoder and the switch information. The figure below shows the electrical diagram of the required wiring.

		5V Out
	4.7kOhm	4.7kOhm
1kOhm		Ch A In

5V	Ch A
	Encoder
GND	Ch B

Ch B In

1kOhm

SW1 SW2

GND

Encoder Module

FIGURE 53. Signals seen by encoder using multi-levels and limit switches

Using this circuit when the switch is open, a 0V (low-level) output from the encoder goes through a 1k and 4.7k voltage divider, thus creating a voltage that will never be below 0.8V at the encoder module’s input.

82 AX3500 Motor Controller User’s Manual Version 1.9b. June 1, 2007