RTS/DCD simulator

Claim 1

In a remote data receiver/transmitter adapted for use with a local multiport data receiver/transmitter having a plurality of transmission ports, each adapted to be connected through a transmission link to the remote data receiver/transmitter, and adapted to be connected to a respective one of a plurality of first data terminals for communication of data from the respective one of the first data terminals to a respective one of a plurality of second data terminals, each connected to one of a plurality of transmission ports of the remote data receiver/transmitter, the improvement in means for maintaining RTS/DCD simulation unless actual data termination occurs, said improvement comprising: means in said transmitter for transmitting a two-part code indicative of termination of actual data, said first part of said two-part code comprising a predetermined stream of binary 1's or 0's of a fixed and preselected number of binary bits, and the second part of said two-part code being a predetermined number of occurrences of a preselected code sequence; means in said receiver for detecting the presence in the data, transmitted for assignment to the respective second data terminal, of a repetitive stream of binary 1's or 0's or operating sequences thereof which is less in number than the transmitted number of bits in said predetermined stream for affording protection against possible transmission errors, and for thereafter detecting the presence of at least one occurrence of a preselected coded sequence of bits within a preselected number of succeeding bits received, wherein said preselected number of succeeding bits includes a plurality of said preselected coded sequences of bits; and means in said receiver/transmitter responsive to said detection means upon detection of both parts of said two-part code for appropriately dropping the DCD/RTS signal.

Claim 8

A method of controlling RTS/DCD simulation by a data modem to a data terminal comprising the steps of: transmitting a two-part code sequence indicative of termination of actual data transfer; including, as a first part of said two-part code, a predetermined number of bits in a repetitive stream of binary 1's or 0's, or operating sequences thereof, and including, as a second part of said two-part code, a preselected code sequence following said binary stream; detecting the presence in the bit stream transmitted for assignment to a data terminal of a second predetermined number of bits less than the transmitted predetermined number in said repetitive stream and for thereafter detecting the presence of at least one occurrence of said preselected coded sequence from within said preselected number of occurrence; and altering, in response to detection of both parts of said two-part code, the RTS/DCD simulation signal.

Claim 9

A method of controlling RTS/DCD simulation by a data modem to a data terminal comprising the steps of: transmitting a two-part code sequence indicative of termination of actual data transfer; including, as a first part of said two-part code, a predetermined number of bits in a repetitive stream of binary 1's or 0's, or operating sequences thereof, and including, as a second part of said two-part code, a preselected code sequence following said binary stream; detecting the presence in the bit stream transmitted for assignment to a data terminal of a second predetermined number of bits less than the transmitted predetermined number in said repetitive stream and for thereafter detecting the presence of at least one occurrence of said preselected coded sequence from within said preselected number of occurrence; and altering, in response to detection of both parts of said two-part code, the RTS/DCD simulation signal.