Title: Rack adapter for serially connected I/O interface racks

Abstract: A rack adapter for a programmable controller is included in each of four remotely located I/O interface racks that are connected in series to a central processor. The rack adapter includes a rack interface processor under program control which converts serial data received from the central processor to parallel data that is written into I/O modules in its rack. The rack interface processor also converts parallel data from I/O modules to serial data, which is sent back to the central processor through a select data out circuit in proper sequence with data from the other racks. The rack interface processor initiates the decontrol of machines connected to the four racks if a major transmission fault occurs, but the rack interface processor is tolerant to transmission errors caused by electrical noise. A dual-frequency clock drives the rack interface processor, and interface circuitry which is operable at two bit-transmission rates connects the rack interface processor to the communication channel, which can range up to 10,000 feet from the central processor.

Do you think this is a good invention? Vote now:

Votes so far: For:(0) Against:(0)
Other info:

Inventors: Galdun, Daniel J. (Huntsburg, OH, US)
Grudowski, Raymond A. (South Euclid, OH, US)
Grants, Valdis (Lyndhurst, OH, US)

Application Number: 007554
Filing Date: 1979-01-29
Publication_date: 1981-03-03
Assignee: Allen-Bradley Company (Milwaukee, WI)
Primary Class(es): 710/2 700/79
Other Classes:
US Patent Ref:

3643223	Feb, 1975	Ruth et al.	364/200.
3810105	May, 1974	England	364/200.
3942158	Mar, 1976	Dummermuth	364/900.
3997879	Dec, 1976	Markley et al.	364/900.
4041473	Aug, 1977	Bardotti et al.	364/900.
4047003	Sep, 1977	LaRocca et al.	364/900.
4104731	Aug, 1978	Grudowski et al.	364/900.
4118792	Oct, 1978	Struger et al.	364/900.

Other Refs:
Primary Examiner: Nusbaum, Mark E.
Assistant Examiner:
Attorney: Quarles & Brady