04275455 is referenced by 19 patents and cites 9 patents.

A programmable logic controller includes a plurality of input interfaces and a plurality of output interfaces for connection to industrial equipment such as automatic assembly equipment, textile machinery, materials handling equipment, and chemical processes. The input and output circuits can be randomly addressed as to their state through an eight bit bus, which connects in parallel with up to 16 groups of eight input and/output circuits. The controller includes groups of timers which are each manually adjustable as to the timing operation and which are sequentially addressed each time a timing function is called for by the program. The timers are designed to be cascaded in groups to virtually any number of timers. The controller includes a scratch pad memory, half of which retains memory upon power failure and half of which does not. The control of the controller by the operator is made more nearly foolproof by interlocking the operations of control switches. Three programming instructions are available which are conditional upon the data in the accumulator of the controller.

Title
Output interface card suitable for use with a programmable logic controller
Application Number
814836
Publication Number
4275455
Application Date
April 2, 1979
Publication Date
June 23, 1981
Inventor
Peter G Bartlett
Davenport
IA, US
Agent
Woodard Weikart Emhardt & Naughton
Assignee
Automation Systems
IA, US
IPC
G06F 3/04
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