Title:
PREVENTION SYSTEM OF MIS-DETECTION FOR OPEN LINE
Document Type and Number:
Japanese Patent JPS5675760
Kind Code:
A
Abstract:
PURPOSE: To prevent the mis-detection of open line at momentary interference at line introduction, by giving the switch drive display signal from an incoming switch drive circuit in the line test frame to the open line mis-detection display section in the line corresponding section of an exchanger.
CONSTITUTION: Address signals D0∼D4 are input to an address latch register 5 to draw in the required line, the output is extended in an address decoder 6 and the corresponding coil among the drive coils LC1∼LC16 is driven. The SET, RESET signals determining the drive and release of the switch are given to a monostable multivibrator to sufficiently guarantee the driving time of the switch.
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| JPH03175769 | TELEPHONE TERMINAL TEST SYSTEM |
Inventors:
OOTSUKA HIROICHI
Application Number:
JP15329979A
Publication Date:
June 23, 1981
Filing Date:
November 27, 1979
Export Citation:
Assignee:
NIPPON ELECTRIC CO
International Classes:
H04M3/26; H04M3/22; (IPC1-7): H04L11/12
Domestic Patent References:
| JPS51127606A | 1976-11-06 |