Browse Prior Art Database

Communication Control System for Multidrop Line

IP.com Disclosure Number: IPCOM000040137D
Original Publication Date: 1987-Sep-01
Included in the Prior Art Database: 2005-Feb-01
Document File: 2 page(s) / 44K

Publishing Venue

IBM

Related People

Moriguchi, S: AUTHOR [+2]

Abstract

In a terminal control system consisting of a main controller and a plurality of auxiliary controllers connected to each other through multidrop serial communication lines, each of the auxiliary controllers comprises a communication control unit connected to the serial communication line for controlling the communication with the main controller and a device control unit connected to the associated I/O device through a device control circuit for controlling the device and provided with plural RAMs each being selectively connectable with the communication control unit and device control unit through a RAM/BUS switch logic.

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Communication Control System for Multidrop Line

In a terminal control system consisting of a main controller and a plurality of auxiliary controllers connected to each other through multidrop serial communication lines, each of the auxiliary controllers comprises a communication control unit connected to the serial communication line for controlling the communication with the main controller and a device control unit connected to the associated I/O device through a device control circuit for controlling the device and provided with plural RAMs each being selectively connectable with the communication control unit and device control unit through a RAM/BUS switch logic. The communication control unit and device control unit are independently operative so that the serial communication of the communication control unit with the main controller and the I/O device control of the device control unit can be concurrently made. After receiving a command from the main controller through the communication control unit, the device control unit executes the instructions read from one of the RAM 1-n units through the RAM/BUS switch logic to control the I/O device and returns a response signal to the communication control unit when the operation is completed. During that time, the communication control unit continues to receive from the main controller the subsequent instructions and data to store in the RAMs through the RAM/BUS switch logic as far as the memory space for them r...