| 摘要 |
PURPOSE:To prevent system-down due to a slave set whose input/output circuit is short- circuited by connecting each slave set to a signal line connected to a master set in the form of multi-drop via relay contacts and opening the relay contacts so as to disconnect only the slave device whose input/output circuit is short circuited. CONSTITUTION:Slave devices 4i (i=1-6) of each house are connected in the form of multi-drop via the relay contacts 3i to the signal line 2 connected to the master set 1 of a supervisor room in a multiple dwelling house. Each slave set is provided with a means detecting the short-circuit of the own signal input/output circuit and when a short-circuit is detected, a detection signal opens the contact 3i so as to disconnect the slave set 4i from the signal line 2. After a prescribed time in the polling signal corresponding to the own address from the master set 1 is elapsed, the contact 3i is closed again to transmit a signal to the master set 1 and the slave device awaits the polling from the master set 1. When no signal comes from the slave device even after a prescribed time is elapsed, the master set 1 displays said slave device as a short-circuited faulty set, opens the contact 3i of the slave set, disconnects it from the signal line 2, and connects the slave devices only whose input/output circuit is not short-circuited to the signal line 2 and controls them remotely. |
