Galil DMC-3425Functional Elements, Microcomputer Section, Motor Interface, Communication

DMC-3425 Functional Elements

The DMC-3425 circuitry can be divided into the following functional groups as shown in Figure 1.1 and discussed below.

WATCHDOG TIMER

ETHERNET

RS-232

68331

MICROCOMPUTER WITH

1 Meg RAM

4 Meg FLASH EEPROM

HIGH-SPEED

MOTOR/ENCODER

INTERFACE

ISOLATED LIMITS AND HOME INPUTS

MAIN ENCODERS AUXILIARY ENCODERS

+/- 10 VOLT OUTPUT FOR SERVO MOTORS PULSE/DIRECTION OUTPUT FOR STEP MOTORS

I/O INTERFACE

HIGH SPEED ENCODER COMPARE OUTPUT

2UNCOMMITTED ANALOG INPUTS

3 PROGRAMMABLE,	3 PROGRAMMABLE
INPUTS	OUTPUTS

HIGH-SPEED LATCH FOR EACH AXIS

Figure 1.1 - DMC-3425 Functional Elements

Microcomputer Section

The main processing unit of the DMC-3425 is a specialized 32-bit Motorola 68331 Series Microcomputer with 1 Meg RAM and 4 Meg Flash EEPROM. The RAM provides memory for variables, array elements and application programs. The flash EEPROM provides non-volatile storage of variables, programs, and arrays. It also contains the DMC-3425 firmware.

Motor Interface

Galil’s GL-1800 custom, sub-micron gate array performs quadrature decoding of each encoder at up to 12 MHz. For standard servo operation, the controller generates a +/-10 Volt analog signal (16 Bit DAC). For sinusoidal commutation operation, the controller uses two DACs to generate two +/-10Volt analog signals. For stepper motor operation, the controller generates a step and direction signal.

Communication

The communication interface with the DMC-3425 consists of one RS-232 port (19.2 kbaud) and one 10base-T Ethernet port.

4 • Chapter 1 Overview DMC-3425