Title:
【発明の名称】伝送路の断線監視装置
Document Type and Number:
Japanese Patent JP2797418
Kind Code:
B2
Abstract:
PURPOSE:To supervise a broken line with simple constitution and to discriminate the kind of broken line by superimposing a DC component of a prescribed level onto a transmission signal, sending the result, extracting the DC component from a reception signal and discriminating the fact of broken line based on the level. CONSTITUTION:A comparator 7 discriminates the reception data from a reception signal at a receiver side 2. On the other hand, a low pass filter 8 extracts a DC component VF corresponding to a transmission offset voltage VOFS from a reception signal. If a broken transmission line 3 takes place, the DC component VF is deviated from a range between threshold levels V2 and V3 are signals L1, L2 go both to an L level. The level of the reception signal is increased to nearly twice in the open state and the DC component VF takes a value close to 2VOFS, then both the signals L1, L2 go to an H level. Then based on the signals L1, L2 as shown in figure, the control section classifies the cases into the said three patterns.
Inventors:
Katsumata Noriaki
Application Number:
JP11787089A
Publication Date:
September 17, 1998
Filing Date:
May 11, 1989
Export Citation:
Assignee:
KABUSHIKI KAISHA MEIDENSHA
International Classes:
H04L12/42; H04B3/46; H04L12/437; (IPC1-7): H04L12/437; H04B3/46
Domestic Patent References:
| JP5164313A | ||||
| JP5333010A | ||||
| JP53141551A | ||||
| JP55100773A | ||||
| JP58125921A | ||||
| JP60195463A | ||||
| JP61108232A | ||||
| JP6152033A | ||||
| JP63312760A | ||||
| JP637827U |
Attorney, Agent or Firm:
Fujiya Shiga (2 outside)