| 摘要 |
PURPOSE:To enable automatic line switching, to reduce operator's burden and to prevent the influence of forgetting switching on other terminals and errors in sending/receiving by equipping line switches which switch line connection and loop-back connection according to a terminal ready signal. CONSTITUTION:A terminal ready ER wire is one of the control wires of lines between terminals 3a-3n and a host computer 1. This wire is to send an ER signal showing that a terminal is ready for sending/receiving to the host com puter through a line. When the ER signal is on (ready for sending/receiving), switches 5a-5n connect lines; when the ER signal is off (not ready for sending/ receiving), the switches 5a-5n make loop-back connection, allowing to execute a loop-back test. |
