DATA COMMUNICATIONS TERMINAL

摘要

B-3647 TCOM DATA COMMUNICATIONS TERMINAL A data communications terminal is provided for interfacing with a central data processing system to handle a variety of data acquisition and control functions including the minitoring and control of security devices and pay television receivers. The terminal includes a microcomputer unit for receiving and processing data from the central processing system and from remote units which generate data signals in response to abnormal conditions. A data reception and transmission unit include a radio frequency modem for converting data to and from a frequency modulated format and a data converter for changing the serial bit data to parallel word data. An identification unit provides data to the microcomputer regarding the identification of the terminal which can be compared to the address portion of the incoming data from the central processing system. Data generating means are provided for generating and transmitting response data to the microcomputer for transmission to the central processing system. An address decode unit identifies and actuates the various element in this system. The remote data terminal functions in an "interrupt" mode with relation to the central data system so that it communicates with the central data system only when abnormal conditions are detected. Otherwise, the terminal handles its own internal monitoring and control functions. Transmission of data to and from the terminal is preferably along coaxial cable. When used in conjunction with a television receiver, the same coaxial cable may be used for the transmission of television signals to the receiver. In this mode, the terminal includes a television port unit which is activiated by the microcomputer to enable access by the receiver to the cable television network in response to appropriate authorization data from the microcomputer.