| 摘要 |
A control system for a variable speed peripheral device which is suitable for remote as well as for local connection of the peripheral device to a central processor. For remote connection, the central processor is coupled to the peripheral device by way of a transmission controller, a remote communication line, and the control system connected to the peripheral device. First and second modems terminate the communication line and are connected through standard interfaces to the transmission controller and to the control system respectively. For this connection, the character transmission rate must be lower than, or equal to, the minimum operating speed of the peripheral device. For local connection, the central processor is coupled to the peripheral device by way of the transmission controller, the control system and the standard interface connected thereto. The latter interface further includes a special output lead connected to indicate the status of the peripheral device to the transmission controller in response to signals received from a control circuit internal to the control system. The transmission controller is thus enabled to transfer data to the peripheral device in the local connection at a rate that varies to meet the instantaneous requirements of the peripheral device. The average transmission rate thus exceeds the transmission rate for remote connection which must conform to the minimum operating speed of the peripheral device.
|
