Browse Prior Art Database

I/O Signals Transmission Communications Software

IP.com Disclosure Number: IPCOM000101147D
Original Publication Date: 1990-Jul-01
Included in the Prior Art Database: 2005-Mar-16
Document File: 3 page(s) / 101K

Publishing Venue

IBM

Related People

Seing, HS: AUTHOR [+2]

Abstract

This article describes a technique to read and write parallel I/O bits at a robotic device remotely located via a serial communication path.

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

I/O Signals Transmission Communications Software

       This article describes a technique to read and write
parallel I/O bits at a robotic device remotely located via a serial
communication path.

      A robotics device is located at a remote station twenty-five
feet away from the control cabinet.  The device requires 20 inputs
and 12 outputs for reading the sensors and controlling the mechanical
motions.  The technique disclosed herein, utilizing RS-232C, makes
the transmission of these I/O signals between the control cabinet and
the robotics device possible using only four wires and still
providing one hundred percent reliability.  In order to make these
I/O interconnections possible, two CPU cards are required.

      The CPU card is an Intel 8052-based system.  Parallel bits I/O
are taken from ports of the 8052.  Two identical CPU cards with
different erasable programmable ROM (EPROM) are utilized.  One
(master) is located at the control panel and another one (slave) is
at the robotic device.

      Software interconnects the two master and slave CPU cards.  The
drawing shows the flow chart of the master.  The flow is described as
follows:

      Upon power-up:
    Master initializes the appropriate registers.  It continuously
sends synchronize blocks to the slave.  If no communications is
established within two seconds, it will set an alarm output and
continue sending synchronize blocks.
    Slave initializes the appropriate registers.  It will set all
outputs to off.  It will wait for synchronize blocks sent by master.
If no communications is established within two seconds, it will set
an alarm output and continue waiting for synchronize blocks.
    When slave receives valid synchronize blocks from the master, it
responds with a synchronize acknowledge and communications begin.

      A.   Once communications has been established:
      a.   Master reads its input ports
      b.   Delay 100 microseconds
      c.   Master re-reads its input ports as in step a.
      d.   Master compares the two consecutive readings in a. and c.
      e.   If the two readings are identical, then go to step
      f.  ...