Operational Characteristics:
The quadrature encoder interface accepts up to two input signals for the counting increment. The index pulse may also be considered should the control configuration require. There is also a Latch and Gate input available on the module for added functionality.
The quadrature encoder provides two signals that are shifted 90 degrees from each other, signals A and B. In order to achieve a better common mode noise rejection ratio, the output signals from the encoder are transmitted via a differential signal. Their complement signals, A(inv.) and B(inv.) are also transmitted. A directional determination may be made by which signal leads. If the A signal leads, the direction is considered to be forward. If the B signal leads, the direction is considered to be reverse. By exchanging the A and A(inv.) the phase relationship will be changed by 180 degrees, thus allowing the direction to be preset via the wiring configuration.
Most quadrature encoders have an Index signal, or Z rev, as well as the incremental signal. This signal provides one pulse per revolution with a duration equal to an incremental pulse.
The inputs to the quadrature encoder module must be supplied from an encoder with Line Driver Outputs for proper operation. The 5 Volt DC output may be used to power the encoder. The 24 Volt DC input supply must be provided from an external power supply.
The Gate and Latch inputs are 24 Volt DC.
Module Inputs and Outputs
Connection | Type |
Signal A and Signal | Input, |
A(inv.) | TTL |
Signal B and Signal | Input, |
B(inv.) | TTL |
Signal C and Signal | Input, |
C(inv.) | TTL |
Shield | Input |
Sensor 0V DC | Output |
Sensor +5V DC | Output |
+24V DC | Input |
0V DC | Input. |
Gate | Input, |
| 24V DC |
Latch | Input, |
| 24V DC |
Function
Incremental pulse signals for channel A
Incremental pulse signals for channel B
Index pulse signals
Shield connection for encoder wiring
Supply return for encoder supply
5 Volt DC supply for encoder
24 Volt DC supply, field connection
Supply return, field connection
24 Volt DC input for gate signal
24 Volt DC input for Latch signal
The Input Gate stops the counter. Only 0 V or an open connection initialize the counter. 24 V stops the counting process.
QuadratureEncoder | 3 |