Browse Prior Art Database

Dynamic Priority Polling

IP.com Disclosure Number: IPCOM000076560D
Original Publication Date: 1972-Mar-01
Included in the Prior Art Database: 2005-Feb-24
Document File: 2 page(s) / 30K

Publishing Venue

IBM

Related People

Beard, JN: AUTHOR [+4]

Abstract

A problem encountered in teleprocessing systems, is the efficient polling of remote terminal equipment for varying needs of the terminal user. In particular, on a multidrop network, the problem exists of maintaining control of units not used continually.

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Dynamic Priority Polling

A problem encountered in teleprocessing systems, is the efficient polling of remote terminal equipment for varying needs of the terminal user. In particular, on a multidrop network, the problem exists of maintaining control of units not used continually.

Shown is a teleprocessing subsystem, in which the program control unit 10 acts as a concentrator for data received or transmitted from communications line 11 to one of a group of remote lines 13, 15, 17, or to one of a group of local I/O devices, 12, 14, 16. Each remote I/O control unit 20, 22, 24, connected to line 13; 30, 32, 34 connected to line 15; and 40, 42, 44 connected to line 17 has an assigned priority. Each of the remote I/O controls such as 40, has attached to it a plurality of I/O devices 41, 43, 45.

I/O devices such as 12, 14, 16, 41, 43, 45 are classified as either active units or inactive units. An inactive unit is defined as any I/O device which does not respond to two successive polling sequences. If any inactive unit responds to a polling sequence, it immediately becomes an active unit.

The polling priority that is established for active units and inactive units is as follows. For each pass of polling all active units, one unit is polled from the inactive priority. The entire subsystem is dynamically reconfigured to the demands of the user and requires no action at the terminal, other than normal operation. The reallocation of priorities is dynamic and dependent only on...