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.

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