04029913 is referenced by 11 patents and cites 4 patents.

A system for electronically selecting and establishing test loop circuits between a remote test position and any of a large number of communication lines at an access location. Extensive logic circuits at the access end and the test end exchange information and display for the operator if the circuit is ready, if there has been a transmission error or component failure, if the circuits are busy, and other factors that affect the system thereby making the operator's task easier. Fail safe circuits prevent opening of telephone lines by access circuitry malfunctions.

Title
Remote accessing system for telephone lines
Application Number
5/672406
Publication Number
4029913
Application Date
March 31, 1976
Publication Date
June 14, 1977
Inventor
Richard A Gunderson
Eden Prairie
MN, US
Agent
Neil B Schulte
Assignee
Magnetic Controls Company
MN, US
IPC
H04B 3/46
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