AMS DCB-274 User Manual

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ADVANCED MICRO SYSTEMS, INC.   
HARDWARE
 
 
 
Introduction 
Thank you for using a DCB-274 Stepper Motor Driver/Controller from ADVANCED MICRO SYSTEMS, INC. 
This unit is designed to provide years of reliable, accurate and cost-effective motion control. As with all 
AMS products, the DCB-274 is backed by over two decades of manufacturing excellence and a commitment 
to quality and support that guarantees your satisfaction. 
 
This manual will assist you in optimizing the performance of your system. Its’ purpose is to provide access 
to information that will facilitate a reliable and trouble-free installation. The manual is organized into the 
following sections:  
 
Section 1: Hardware. Section 1 is a description of the physical product, i.e., connections, physical and 
electrical characteristics and a “quick start” guide to get you up and running. 
 
Section 2: Serial Interface. Section 2 defines all AMS serial communication protocols and highlights the 
specific protocol and hardware required for single and multi-axis operation. 
 
Section 3: SMC-27X2 Software Commands. Section 3 details the software instructions and related 
parameters of the SMC-27X2 micro-controller that powers the DCB-274. 
 
Section 4: Addendum. Pertinent schematics, charts, etc. are contained in Section 4. 
 
In addition to the Users Manual, a PC/AT compatible systems integration diskette (EASI) is supplied. This 
powerful programming tool is an easy to use, menu driven utility file with on-line help screens and available 
source code (Microsoft "C"). Used together, the Users Manual and EASI diskette will enable you to quickly 
take advantage of the advanced programming features and system capabilities inherent in the system 
design. 
 
Although the DCB-274 and supporting documentation were designed to simplify the installation and on-
going operation of y our equipment, we recognize that the integration of motion control often requires 
answers to many complex issues. Please feel free to take advantage of our technical expertise in this area by 
calling one of our support personnel to discuss your application at 603-882-1447. 
 
Limitations or Exceptions for the DCB-274 
The SMC-27X2 micro-controller used on the DCB-274 has capabilities or functions that vary from product to 
product. Therefore, some topics in this manual include descriptions of commands or hardware that may not 
be pertinent to the DCB-274, such as: 
 
Serial interface 
While it is possible to use a simple 3 wire RS-232 design, the DCB-274 is designed for a 5-volt differential 
RS-422 implementation only. 
 
Current controls 
The hold and run currents are  adjusted with a software command (Y) that allows automatic hold current 
setback. 
 
Encoder input  
The Encoder input option allows quadrature digital inputs to be converted to step and direction for jogging 
or “shuttle” control. For encoder “feedback” or “closed-loop” control, AMS offers it’s MAX series 
products. Encoder "feedback" is not possible with the DCB-274. 
 
Moving signal 
 Some AMS products have a “moving” signal available on the serial connector. The signals from all axes are 
combined to provide an “any-moving” signal. Determination of moving status, on the DCB-274, is better 
done using the Read Moving Status (^) command.  
 
For applications requiring this type of signal, a mode using the small “l” command is available to allow port 4 
to become a hardware “moving” output.