Signal transmission apparatus

• US 5,815,074 A
• Filed: 04/02/1996
• Issued: 09/29/1998
• Est. Priority Date: 04/26/1995
• Status: Expired due to Fees

• Current Assignee: ALPS Electric Company Limited (Alps Alpine Co., Ltd.)
• Original Assignee: ALPS Electric Company Limited (Alps Alpine Co., Ltd.)
• Inventors: Sasagawa, Shinichi, Ichimiya, Nobuyuki, Kinouchi, Shin, Namioka, Seishi
• Primary Examiner(s): MULLEN, THOMAS J
• Application Number:
  US08/626,788
• Time in Patent Office: 910 Days
• Field of Search: 340/568, 340/531, 340/533, 340/538, 340/309.15, 340/693, 340/505, 340/514, 340/825.08, 340/825.54, 340/425.1
• US Class Current: 340/505
• CPC Class Codes: G08B 25/04 using a single signalling line, e.g. in a closed loop
• CPC Class Codes: G08C 2201/40 Remote control systems using repeaters, converters, gateways
• CPC Class Codes: G08C 23/04 using light waves, e.g. infrared

Abstract

A signal transmission apparatus including a main unit having a signal transmission terminal, and one or more sub units (or repeaters) each having first and second signal transmission terminals. A loop connection line is provided between the main unit and a first sub unit, and additional loop connection lines are provided between subsequent pairs of sub units to convey signals from the main unit to each of the sub units, and from each of the sub units to the main unit. The main unit includes a controller, a signal generator for generating and sending a first signal to one of the sub units, and a signal processor for processing a second signal returned from one of the sub units in response to the first signal. Each of the sub units includes a controller, a destination signal determination section, and a signal transfer section for selectively capturing and transferring a signal according to its destination address.

Claims

1. A signal transmission apparatus comprising:

a main unit having a first signal transmission terminal including first and second photocouplers;

a sub unit having a second signal transmission terminal and a third signal transmission terminal, each of the second signal transmission terminal and the third signal transmission terminal including first and second photocouplers; and

a plurality of loop connection lines including a first loop connection line linking the first signal transmission terminal of said main unit and said second transmission terminal of said sub unit, and a second loop connection line connected to said third signal transmission terminal of said sub unit;

wherein said main unit further includes control means, signal generating means for generating and sending a first current signal to said sub unit in response to control signals from said control means, and signal processing means for processing a second current signal received from said sub unit, and

wherein said sub unit further includes control means, in a destination signal determination means for determining a destination of said first current signal supplied to said second signal transmission terminal, and signal transfer means for capturing said first current signal if, based on a result of determination made by said destination signal determination means, said first current signal is addressed to said sub unit, for transferring said first current signal to said third signal transmission terminal if said first current signal is not addressed to said sub unit, and for transferring said second current signal supplied to said third signal transmission terminal from said second loop connection line to said first signal transmission terminal through said second signal transmission terminal and said first loop connection line.

2. A signal transmission apparatus according to claim 1, wherein said main unit is incorporated into a theft monitoring apparatus for performing theft monitoring by a plurality of tags and said sub unit is a repeater connected to said plurality of tags.

3. A signal transmission apparatus comprising:

a main unit having a first signal transmission terminal including first and second photocouplers;

a sub unit having a second signal transmission terminal and a third signal transmission terminal, each of the second signal transmission terminal and the third signal transmission terminal including first and second photocouplers; and

a plurality of loop connection lines including a first loop connection line linking the first signal transmission terminal of said main unit and said second transmission terminal of said sub unit, and a second loop connection line connected to said third signal transmission terminal of said sub unit;

wherein said main unit further includes control means, number command means for sending a number setting command signal to said sub unit in response to a command signal from said control means, and response signal receiving means for receiving a response signal coming from said sub unit, and

wherein said sub unit further includes control means, number setting means for generating, based on said number setting command signal supplied to said second signal transmission terminal, a sub unit number for said sub unit, said sub unit number indicating a sequential connection position of said sub unit relative to said main unit, and display means for displaying said sub unit number generated by said number setting means.

4. A signal transmission apparatus according to claim 3, wherein said sub unit further comprises completion signal generating means for generating a setting completion signal and for sending the setting completion signal from said second signal transmission terminal after the sub unit number of said sub unit has been set by said number setting means, and new number command means for generating a second number setting command signal and for sending the second number setting command signal from said third signal transmission terminal after the sub unit number of said sub unit has been set by said number setting means.

5. A signal transmission apparatus according to claim 4, wherein said completion signal generating means of said sub unit further comprises means for, if a second setting completion signal is not supplied to said third signal transmission terminal within a certain time after transmission of said second number setting command signal from said new number command means from said third signal transmission terminal, sending said sub unit number from said second signal transmission terminal.

6. A signal transmission apparatus according to claim 3, wherein said main unit is incorporated into a theft monitoring apparatus for performing theft monitoring by a plurality of tags and said sub unit is a repeater connected to said plurality of tags.

7. A signal transmission apparatus comprising:

a main unit having a first signal transmission terminal including signal sending means and signal receiving means;

a sub unit having a second signal transmission terminal and a third signal transmission terminal, each of the second signal transmission terminal and the third signal transmission terminal including a signal sending means and signal receiving means; and

a plurality of loop connection lines including a first loop connection line linking the first signal transmission terminal of said main unit and said second transmission terminal of said sub unit, and a second loop connection line connected to said third signal transmission terminal of said sub unit;

wherein said main unit further includes control means, signal generating means for generating and sending a first voltage signal to said sub unit in response to control signals from said control means, and signal processing means for processing a second voltage signal received from said sub unit, and

wherein said sub unit further includes control means, a destination signal determination means for determining a destination of said first voltage signal supplied to said second signal transmission terminal, and signal transfer means for, based on a result of determination made by said destination signal determination means, capturing said first voltage signal supplied to said second signal transmission terminal if said first voltage signal is addressed to said sub unit and, if said first voltage signal is not addressed to said sub unit, transferring said first voltage signal to said third signal transmission terminal and transferring said first voltage signal on said second loop connection line.

8. A signal transmission apparatus according to claim 7, wherein said main unit is incorporated into a theft monitoring apparatus for performing theft monitoring by a plurality of tags and said sub unit is a repeater connected to said plurality of tags.