Title:
LOOP BACK DEVICE
Document Type and Number:
Japanese Patent JPH01185713
Kind Code:
A
Abstract:
PURPOSE:To prevent the inspective capacity of a loop back device from being lowered by constituting a device so that a current or a voltage can be supplied from the pull-up resistor of an interface by using an active inversion device. CONSTITUTION:The loop back device 100 is constituted by connecting the active inversion devices 142 and 143 so that the current or the voltage can be supplied from the pull-up resistors (15-18) of the interface 99. In other words, since the active inversion devices 142 and 143 are used, the influence of a fault in input terminals (1-4) is not affected on the active inversion devices 142 and 143 connected to front stages before the active inversion devices 142 and 143 whose input parts are connected to the input terminals (1-4). Therefore, the combination of the input signals of the interface is formed differently with each other even when the fault is generated in either the input terminals (1-4). In such a way, it is possible to prevent the inspective capacity from being lowered even when the number of the input terminals of the interface is increased.
Inventors:
NAKAJIMA TADASHI
Application Number:
JP1051188A
Publication Date:
July 25, 1989
Filing Date:
January 20, 1988
Export Citation:
Assignee:
FUJI XEROX CO LTD
International Classes:
B41J5/30; G03G15/00; G03G21/00; G06F3/00; G06F13/00; H04L13/00; H04L25/02; H04L69/40; (IPC1-7): B41J5/30; G03G15/00; G06F3/00; G06F13/00; H04L13/00
Attorney, Agent or Firm:
Michito Hiraki (1 person outside)