| 摘要 |
Procedure and apparatus for a workstation for an ARQ system, (which includes a transmitter unit (fig. 2) and a receiver unit (fig. 2), and which is normally intended for the transfer of traffic messages in the form of data blocks to a similarly constructed workstation), for the transfer of special messages, which infrequently arise. The apparatus can work in two modes, a traffic mode and a special message mode, with the mode being changed by a special sequence of signals. The transmitter can, during the transmission of traffic messages, at arbitrary instances, interrupt the normal traffic transmission by transmitting a special sequence of signals in and for the transfer of a special message, which can, for example, concern changing the transmitter channel, speech messages to the operator at the receiver etc. The receiver reacts to the signal sequence and shifts to special message mode. Shifting back to the traffic mode is carried out by means of a new special signal sequence, whereby the interrupted traffic transfer is resumed from where it stopped. The same or different signal sequences can be used for changing from traffic mode to service message mode and from service message mode to traffic mode.<IMAGE> |
