Galil DMC-3425 user manual General I/O, System Elements, Motor, Amplifier Driver

General I/O

The DMC-3415 provides interface circuitry for 7 TTL inputs and 3 TTL outputs. In addition, the controller provides two 12-bit analog inputs. The general inputs can also be used for triggering a high- speed positional latch for each axis.

NOTE: In order to accommodate 2 axes on the DMC-3425, many of the general I/O features become dedicated I/O for the second axis. The standard DMC-3425 will have 3 TTL inputs, 3 TTL outputs and 2 analog inputs. If extra I/O is needed, the DB-14064 I/O daughter card increases general purpose I/O by 64 points.

System Elements

As shown in Fig. 1.2, the DMC-3425 is part of a motion control system, which includes amplifiers, motors and encoders. These elements are described below.

Power Supply

Computer DMC-3425 Controller

Encoder

Figure 1.2 - Elements of Servo systems

Amplifier (Driver)

Motor

Motor

A motor converts current into torque, which produces motion. Each axis of motion requires a motor sized properly to move the load at the required speed and acceleration. (Galil's "Motion Component Selector" software can help you with motor sizing). Contact Galil for more information.

The motor may be a step or servo motor and can be brush-type or brushless, rotary or linear. For step motors, the controller is capable of controlling full-step, half-step, or microstep drives. An encoder is not required when step motors are used.

Amplifier (Driver)

For each axis, the power amplifier converts a +/-10 Volt signal from the controller into current to drive the motor. For stepper motors, the amplifier converts step and direction signals into current. The amplifier should be sized properly to meet the power requirements of the motor. For brushless motors, an amplifier that provides electronic commutation is required or the controller must be configured to provide sinusoidal commutation. The amplifiers may be either pulse-width-modulated (PWM) or linear. They may also be configured for operation with or without a tachometer. For current amplifiers, the amplifier gain should be set such that a 10 Volt command generates the maximum required current. For example, if the peak motor current is 10A, the amplifier gain should be 1 A/V. For velocity mode amplifiers, 10 Volts should run the motor at the maximum speed.

DMC-3425 Chapter 1 Overview• 5