초록 ▼

A voiceband data set network includes a control data set (10), a plurality of tributary data sets (4a, 4b . . . 4n) and a diagnostic control device (5). User-provided data is communicated between the control data set and the tributary data sets via a primary channel within a four-wire private teleph

A voiceband data set network includes a control data set (10), a plurality of tributary data sets (4a, 4b . . . 4n) and a diagnostic control device (5). User-provided data is communicated between the control data set and the tributary data sets via a primary channel within a four-wire private telephone line (11, 12). Diagnostic and control information is communicated between the control data set and the tributaries via a secondary channel within the private line. Diagnostic and control information is communicated between the diagnostic control device and the control data set, with which it is co-located, via a control channel. Each data set includes a data set diagnostic unit (50), or DDU, via which it transmits and receives the diagnostic and control information. Communications among the DCD, DDUs, and primary controllers within the data sets, are carried out on a link-by-link basis, with the DDUs serving as message switching nodes and with communications over each link being principally comprised of requests and reads. The DCD, DDUs and primary controllers communicate in a hierarchy in which requests and reads are always directed downstream. The tributary data sets provided, however, with a way of directing request-type message texts upstream.

대표청구항 ▼

A first data set adapted to be connected to at least a second data set via a communication link, said first data set including means (20, 30) for transmitting data signals to said second data set over said link and for receiving data signals from said second data set over said link and upstream diag

A first data set adapted to be connected to at least a second data set via a communication link, said first data set including means (20, 30) for transmitting data signals to said second data set over said link and for receiving data signals from said second data set over said link and upstream diagnostic means (40, 510, 520, 1001, 1007) for transmitting over said link texts identifying predetermined tests to be initiated by said second data set, characterized by maintenance mode means (30, 40, 1001, 1002, 1004, 1011) for initiating at least a first predetermined test in response to maintenance mode texts received over said link identifying said at least first test.