JPS57123751A - Data communication system - Google Patents

Data communication system

Info

Publication number
JPS57123751A
JPS57123751A JP56008647A JP864781A JPS57123751A JP S57123751 A JPS57123751 A JP S57123751A JP 56008647 A JP56008647 A JP 56008647A JP 864781 A JP864781 A JP 864781A JP S57123751 A JPS57123751 A JP S57123751A
Authority
JP
Japan
Prior art keywords
polling
circuit
signal
tdn
indication
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
JP56008647A
Other languages
Japanese (ja)
Inventor
Masao Higuchi
Nobuyuki Ishida
Makoto Hirogami
Tokihide Hara
Ikuo Wakayama
Ryuichi Toki
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
Hitachi Ltd
NEC Corp
Oki Electric Industry Co Ltd
NTT Inc
Original Assignee
Fujitsu Ltd
Hitachi Ltd
NEC Corp
Nippon Telegraph and Telephone Corp
Oki Electric Industry Co Ltd
Nippon Electric Co 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, Hitachi Ltd, NEC Corp, Nippon Telegraph and Telephone Corp, Oki Electric Industry Co Ltd, Nippon Electric Co Ltd filed Critical Fujitsu Ltd
Priority to JP56008647A priority Critical patent/JPS57123751A/en
Publication of JPS57123751A publication Critical patent/JPS57123751A/en
Pending legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04Q—SELECTING
    • H04Q9/00—Arrangements in telecontrol or telemetry systems for selectively calling a substation from a main station, in which substation desired apparatus is selected for applying a control signal thereto or for obtaining measured values therefrom

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Small-Scale Networks (AREA)
  • Communication Control (AREA)

Abstract

PURPOSE:To perform normal communication even if a fault state is generated owing to the transmission delay of a trunk line, by preventing an increase in the traffic of the trunk line from being caused, by inhibiting a signal characteristic to a polling system from being sent to the trunk circuit. CONSTITUTION:A polling scheduling circuit 1 schedules polling for subordinate terminals TD1-TDn. For a schedule for the polling for the subordinate terminals TD1-TDn in the order of their suffixes, a scheduling table which stores polling signals for the subordinate terminals TD1-TDn successively is provided. When the circuit 1 reads the polling signal for the terminal TD1, a polling indication is supplied to a polling-indication-signal generating circuit 2 together with the polling signal. This circuit 2 generates a polling indication signal, which is sent to a trunk line L1 via a transmitting circuit 3 together with the polling signal.
JP56008647A 1981-01-23 1981-01-23 Data communication system Pending JPS57123751A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP56008647A JPS57123751A (en) 1981-01-23 1981-01-23 Data communication system

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP56008647A JPS57123751A (en) 1981-01-23 1981-01-23 Data communication system

Publications (1)

Publication Number Publication Date
JPS57123751A true JPS57123751A (en) 1982-08-02

Family

ID=11698730

Family Applications (1)

Application Number Title Priority Date Filing Date
JP56008647A Pending JPS57123751A (en) 1981-01-23 1981-01-23 Data communication system

Country Status (1)

Country Link
JP (1) JPS57123751A (en)

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