3842218 is referenced by 19 patents and cites 5 patents.

Line condition reporting and subscriber polling apparatus employs a central processor for accessing subscriber cable pair via one of plural interface circuits, a trunk selection matrix, a test or no-test trunk, and the subscriber's central office.Subscriber lines may be seized in accordance with manual or automatically entered information via system input terminals, and an operative code-forming part of the input command, determines whether the system will operate in a line testing and/or polling (as utility meter) mode.

Title
Automated telephony testing and polling apparatus
Application Number
05/313,817
Publication Number
3842218
Application Date
December 11, 1972
Publication Date
October 15, 1974
Inventor
Mickowski John
Manos George
Gazzo Jr John J
Santulli Vincent F
DeLuca Paul V
Agent
Amins Philip D
Assignee
Porta Systems Corporation
IPC
H04b 03/46
H04M 03/28
H04M 03/30
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