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.)
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.)
British Telecommunications PLC
British Telecommunications Research Ltd
Original Assignee
British Telecommunications PLC
British Telecommunications Research 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 British Telecommunications PLC, British Telecommunications Research LtdfiledCriticalBritish Telecommunications PLC
Application grantedgrantedCritical
Publication of FR985814ApublicationCriticalpatent/FR985814A/fr
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
H04Q9/08—Calling by using continuous AC
H04Q9/10—Calling by using continuous AC using single different frequencies
Landscapes
Engineering & Computer Science
(AREA)
Computer Networks & Wireless Communication
(AREA)
FR985814D1948-05-311949-05-09Perfectionnements aux systèmes de transmission de signaux
ExpiredFR985814A
(fr)