Gregory L Merrell

US Patent:

42284953, Oct 14, 1980

Filed:

Dec 19, 1978

Appl. No.:

5/970959

Inventors:

Theodore L. Bernhard - Mentor on the Lake OH
Ernst Dummermuth - Chesterland OH
Thomas M. Hoch - Woodmere OH
Bruce S. Jaffe - Mayfield Heights OH
Gregory L. Merrell - Cleveland Heights OH

Assignee:

Allen-Bradley Company - Milwaukee WI

International Classification:

G05B 1918
G06F 1516

US Classification:

364101

Abstract:

A numerical control system includes a main processor which performs such functions as interpolation and outputting of motion command signals to the servomechanisms on a machine tool. A separate programmable interface processor connects to the main processor bus structure and it operates as a programmable controller to control the discrete digital I/O devices associated with the machine tool. A third processor couples through a serial data link with the main processor and it operates to service peripheral I/O devices associated with the front control panel on the numerical control system.

US Patent:

42636477, Apr 21, 1981

Filed:

Feb 7, 1979

Appl. No.:

6/009938

Inventors:

Gregory L. Merrell - Cleveland Heights OH
Theodore L. Bernhard - Mentor On The Lake OH

Assignee:

Allen-Bradley Company - Milwaukee WI

International Classification:

G06F 1516
G06F 1130

US Classification:

364101

Abstract:

Associated with each processor in a multiprocessor numerical control system is a watchdog timer circuit which is periodically reset by its processor under normal operating conditions. If a malfunction should occur in one of the processors, its watchdog timer is not reset and it times out. A fault monitor line connects to each watchdog timer circuit and an emergency stop circuit, and when a malfunction occurs in any one of the processors, this condition is indicated to all the processors and to the emergency stop circuit.