Specifications

SECTION 1 INTRODUCTION
5
SECTION 1 - INTRODUCTION
This manual is intended to help the user apply
the SMC40 family of products in motion control
applications. Familiarity with computers,
programmable logic controllers (PLC's), or
terminals is helpful, but is not essential.
The SMC40 family of products is based on
Anaheim Automation’s advanced step motor
controller integrated circuit. This high speed
microprocessor uses a simple language that can
access over 125 different commands. These
commands deal with motion parameters,
encoders, inputs and outputs, variables, math
functions, and much more. This functionality
produces a very powerful step motor indexer
that is able to handle even the most
complicated machine control. Expansion
Modules have been added for this series to
include easy use of external thumbwheel
modules, external terminals, and additional
inputs.
The SMC40 has two modes of operation: Direct
Mode and Stored Program Mode. In Stored
Program Mode a whole program is stored in the
SMC40’s internal memory (16,000 bytes). Once
a program has been sent to memory, it is non-
volatile meaning if the power is turned off, the
program will still remain in the memory. In
Direct Mode, commands are sent to the unit via
a serial port and are executed one command at
a time.
A step motor is essentially a digital device. If
you give the step motor driver 10 clock pulses
the motor moves 10 steps. Sometimes a
closed-loop system is needed to verify that the
motor indeed moved 10 steps. The SMC40 will
accept encoder inputs to form a closed-loop
system.
The SMC40 is designed to communicate over a
RS232C or RS422 bi-directional serial data bus.
The RS422 serial bus is better suited for
industrial environments susceptible to
electrically noisy conditions. RS422 can reliably
travel to a distance of 4000 feet. The RS232C
line can only be used to a distance of 50 feet in
a noise free environment.
Almost all computers have, or can be equipped
with, an RS232 port. If you wish to send your
RS232C signal over 50 feet, Anaheim
Automation manufactures a RS232C to RS422
Data Converter (Model DC1709).
The SMC40 provides programming of
acceleration, base speed (start up speed),
running speed, and the number of steps to be
taken in both relative and absolute positioning
modes. On absolute positioning moves, the
SMC40 automatically determines the proper
direction to go and the number of steps to take.
The relative positioning will move a number of
steps in the direction that the user defines. The
SMC40 has a high level command set including:
looping, conditional statements, time delays,
power down motor, encoder feedback,
maskable I/O and open-collector (NPN) outputs.
Hard, Soft, and Home Limit Switch inputs are
provided for each axis. These features are
generally required in most machine control
designs. 96 Inputs and 24 Outputs are provided
per unit. These I/O may be used for monitoring
and controlling machine operation and/or
interaxis coordination. These I/O are accessible
independent of the busy state of the axis
controls. The Inputs are TTL/CMOS
compatible. The Outputs are current sinking,
open collector darlingtons.
The SMC40 has a built-in programmable reset
circuit so that all axes in the daisychain may be
reset. The outputs are reset to the off state
when the board is reset. Reset is automatic on
power-up or with a "break" signal on the RS232
or RS422 input. Windows software is provided
when you purchase the unit. This software
allows you to write and change programs that
are to be stored in the SMC40 for autostart use.
The software also allows you to save the
programs onto your computer disk, and easily
retrieve them when needed. The program can
upload the stored program from the SMC40,
allow you to make changes, and then download
the program back to the SMC40.