Browse Prior Art Database

Multitasking Control System Using Priority Based Scheduling

IP.com Disclosure Number: IPCOM000106957D
Original Publication Date: 1992-Jan-01
Included in the Prior Art Database: 2005-Mar-21
Document File: 3 page(s) / 91K

Publishing Venue

IBM

Related People

Abbattista, A: AUTHOR [+3]

Abstract

Disclosed is the control technique used which an automated handling system of a Via Inspection Tool which incorporates an off the shelf multitasking operating system on an STD-Bus and takes advantage of its priority-based scheduling capabilities.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 52% of the total text.

Multitasking Control System Using Priority Based Scheduling

       Disclosed is the control technique used which an
automated handling system of a Via Inspection Tool which incorporates
an off the shelf multitasking operating system on an STD-Bus and
takes advantage of its priority-based scheduling capabilities.

      The Std-Bus serves as the hardware controller in the tool and
is connected to a PC-AT master controller by an RS-232C serial link.
A system's VRTX operating system is used with Std-Bus boards supplied
by ZIATECH A MICROPROCESSOR, a slave processor for serial
communication, digital I/O cards, and motor controller cards.

      The tool is an I/O intensive transport system for delivery and
removal of ceramic sheets through an inspection operation.  Real time
response to sensor inputs is required for coordination of the
transport system.  In addition, communications between the STD-BUS
AND the Std-bus and the PC-AT must be handled in a timely manner.

      The figure shows the multitasking architecture used to control
the tool.  The Std-bus microprocessor contains an EPROM-based BIOS
and DOS.  These present the application with a PC compatible
interface for running applications. The board support provides the
link from the kernel to the underlying hardware.  An interface
library supplies a 'C' language application interface to the kernel.
Two communication device drivers create a DOS-like I/O interface to
the PC-AT master controller over the RS-232C serial link.

      The application code is written in 'C' and complied for running
in a DOS environment.  The supplied compiler libraries have been
modified to work with the kernel.

      The application code is organized around the major subsystems
of the transport hardware.  One routine controls each subsystem.  The
kernel creates sep...