User manual

Barrett Technology, Inc.
BA4-310 System User Manual Version 1.1
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BarrettArm. This cable provides power to and feedback from a BarrettHand mounted on a 7-
DOF BarrettArm system.
1.5 Host Computer
The BarrettArm system has been tested with, and operates with, the following host computer:
Dell Dimension XPS H266 (Pentium II) with 64M of RAM
. Similarly configured PC computers
from other manufacturers should also be sufficient. Barrett recommends using the fastest CPU
available to the user for best performance. The host computer must have one full length ISA
bus slot available for the MEI motion control board.
1.6 Motion Control Board
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The PC/DSP motion controller from Motion Engineering, Inc. (MEI) uses a powerful Analog
Devices 40 MHz DSP to provide up to 8 axes of servo or stepper control in a single ISA bus
slot. Hardware features include 16-bit servo outputs, encoder inputs to 5 MHz, 8 channels of
12-bit analog inputs, and up to 44 lines of user I/O.
Programming the PC/DSP is easy using MEI's flexible C function libraries with over 250
motion control functions. MEI C libraries combine with compilers from Microsoft, Borland,
Watcom, Symantec, and others to speed development of complex motion applications.
The PC/DSP provides a rich set of software algorithms, including a sophisticated second-order
PID control algorithm with velocity, acceleration, and friction feed-forward.
Advanced features include electronic gearing and camming, dual-loop control, circular and
linear interpolation, and trapezoidal, S-curve, parabolic, and custom motion profiles.
The PC/DSP allows motion control programs to share execution between the on-board DSP
(for numerically-intensive real-time functions) and the host (for non-real-time functions). This
results in an ideal division of labor with minimal host intervention.
1.7 Safety Circuit
The Safety Circuit is system that monitors the state of the robot and shuts the system down
when a fault occurs. When the system is shut down by the Safety Circuit the energy in the
motors and the controllers is shunted across a regenerative resistor. When the system is
tripped, the arm will fall to its’ least energy state.
The Safety Circuit will shut down under the following circumstances:
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Excerpts taken from http://www.motioneng.com/product/pcxdsp/overview.htm (1998)