JPS56153872A - Alarm system to station - Google Patents

Alarm system to station

Info

Publication number
JPS56153872A
JPS56153872A JP5654380A JP5654380A JPS56153872A JP S56153872 A JPS56153872 A JP S56153872A JP 5654380 A JP5654380 A JP 5654380A JP 5654380 A JP5654380 A JP 5654380A JP S56153872 A JPS56153872 A JP S56153872A
Authority
JP
Japan
Prior art keywords
station
level
alarm
output signal
pilot
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
JP5654380A
Other languages
Japanese (ja)
Inventor
Koji Aoki
Hiroshi Yamada
Kenji Watanabe
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Fujitsu Ltd
Original Assignee
Fujitsu Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Fujitsu Ltd filed Critical Fujitsu Ltd
Priority to JP5654380A priority Critical patent/JPS56153872A/en
Publication of JPS56153872A publication Critical patent/JPS56153872A/en
Pending legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04J—MULTIPLEX COMMUNICATION
    • H04J1/00—Frequency-division multiplex systems
    • H04J1/02—Details
    • H04J1/16—Monitoring arrangements

Abstract

PURPOSE:To transmit and receive many kinds of alarm systems to station, by causing fluctuation time lengths of the pilot signal level to correspond to kinds of station alarm, in the station alarm system where the transmission level of the pilot signal is changed. CONSTITUTION:When an alarm to station is transmitted, that is, transmission switching signal of the alarm to station (a) or (b) is ''0'', pulse generator 30 oscillates, and output signal (c) alternates at period DELTAt. Trigger circuits 32 and 33 differentiate switching signals (a) and (b) to generate trigger outputs (d) and (e), and timer circuits 34 and 35 are triggerred to hold state ''1'' during times T1 and T2 respectively. Consequently, output signal (h) of OR circuit 36 holds state ''1'' furthermore during T1 or T2. Therefore, output signal (i) of ANd circuit 37 alternates between ''1'' and ''0'' at period DELTAt during time T1 or T2. Consequently, constant- current source 44 repeates turning-on and off at period DELTAt during time T1 or T2, and the pilot level is fluctuated between the reference level and the low level. After time T1 or T2, output signal (i) is fixed to the low level, and the pilot level is fixed to the low level.
JP5654380A 1980-04-28 1980-04-28 Alarm system to station Pending JPS56153872A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP5654380A JPS56153872A (en) 1980-04-28 1980-04-28 Alarm system to station

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP5654380A JPS56153872A (en) 1980-04-28 1980-04-28 Alarm system to station

Publications (1)

Publication Number Publication Date
JPS56153872A true JPS56153872A (en) 1981-11-28

Family

ID=13029996

Family Applications (1)

Application Number Title Priority Date Filing Date
JP5654380A Pending JPS56153872A (en) 1980-04-28 1980-04-28 Alarm system to station

Country Status (1)

Country Link
JP (1) JPS56153872A (en)

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