| 摘要 |
PURPOSE:To realize an access control system which informs the success of catching a token, by providing repeating devices connected in a loop form and an adaptor which controls these repeating devices nd a node interface. CONSTITUTION:A function to repeat the frames on a transmission line is provided to a repeating device 3, and a repeating is indicated from an adaptor 2 containing an access control circuit. The device 3 and the adaptor 2 are set independently of each other with a distance secured between them. The device 3 receives an indication from the adaptor 2 to catch a token and detects a free token frame on a loop circuit. Then the bit showing a free token busy token is set in a busy token mode to form a frame to which another bit showing the catch of a free token. This frame is repeated and at the same time transferred to the adaptor 2 to inform a success of catching a token. |
