A-B Ultra5000 Intelligent Servo Drives Encoder Interface

Encoder Interface

The Ultra5000 main encoder feedback connector is CN2. The motor encoder

interface circuitry features include:

• 2.5 MHz maximum line frequency

• RS-485 serial channel for communicating with intelligent encoders

• Hall input for start-up commutation only

• Interpolation of sine/cosine encoders

All encoder signals are filtered using analog and digital filtering. The inputs

also include illegal state change detection. Refer to Figure 2.5 for a schematic

of the motor encoder inputs.

Hardware latches can be used for latching the encoder position based on an

index input or a digital input transition.

Auxiliary Encoder Interface

All encoder input signals (CN1B) are filtered using analog and digital filtering,

including illegal state change detection.

The input circuitry includes pull-up and pull-down resistors for compatibility

with single-ended and open collector signals, in addition to differential signals.

A single channel schematic of the auxiliary encoder interface is shown in the

figure below.

Understanding Serial Interfaces

The Ultra5000 contains two identical serial port connectors (Main Serial Port

CN3A and Auxiliary Serial Port CN3B) that implement the standard NRZ

asynchronous serial format, and support RS-232. RS-422. and RS-485

communication standards.

Standard baud rates include 1.200. 2.400. 4.800. 9.600. 19.200. and 38.400

baud. Data lengths of 7 and 8 bits are supported.

The connector pinout dedicates separate pins for the RS-232 and RS-422/

RS-485 signals, so that the communication standard can be changed by just

using a different cable. Refer to Figure 2.7 for the serial interface hardware

configuration.

Routing High and Low Voltage Cables

Be aware that when you connect and route power and signal wiring on a

machine or system, radiated noise from nearby relays (relay coils should have

surge suppressors), transformers, and other electronic drives can be induced

into motor or encoder feedback, communications, or other sensitive, low

voltage signals. This can cause system faults and communication problems. To

minimize the levels of radiated noise, route machine power and signal lines

separately.