Building automation system having expansion modules

• US 5,528,215 A
• Filed: 05/31/1994
• Issued: 06/18/1996
• Est. Priority Date: 05/31/1994
• Status: Expired due to Term

• Current Assignee: Siemens Industry Incorporated (Siemens AG)
• Original Assignee: Landis & Gyr Powers, Inc. (Landis+Gyr Group AG)
• Inventors: Mueller, Robert P., Racke, Thomas F., Siu, Raymond S.
• Primary Examiner(s): Swarthout, Brent A.
• Assistant Examiner(s): POPE, DARYL C
• Application Number:
  US08/251,462
• Time in Patent Office: 749 Days
• Field of Search: 340/286.02, 340/286.01, 340/310 R, 340/310 A, 340/310.06, 340/825.52, 340/825.54, 340/825.06, 364/132, 364/133, 364/138, 364/139, 364/441
• US Class Current: 340/286.01
• CPC Class Codes: G05B 19/0421 Multiprocessor system
• CPC Class Codes: G05B 2219/21015 Easy expansion, extension of I-O
• CPC Class Codes: G05B 2219/25139 Use of separate buscouple interface
• CPC Class Codes: G05B 2219/25146 Communication between main and expansion unit, only clock and data
• CPC Class Codes: G05B 2219/25314 Modular structure, modules
• CPC Class Codes: G05B 2219/25325 Each connected module has own power supply

Abstract

A building automation system is disclosed which enables reliable operation and cost effective expansion. The system utilizes pairs of complementary modules, one of which is a primary module that is installed at a main cabinet and the other is an expansion module that can be located adjacent the mechanical systems which are to be monitored and controlled. Through the use of the complementary pairs of modules, the necessity for providing home runs of power conductors from the mechanical system to the main cabinet are substantially reduced if not eliminated, which greatly reduces the costs of materials and labor in a total installation.

Claims

1. A building automation system of the type which is controllable by a computer means via a network, said system comprising:

a main cabinet means including a rail means, said rail means including a data conduction means for providing bidirectional data communications along said rail means;

said rail means further including a clock signal conduction means, an AC power conduction means, a DC power conduction means and a ground conduction means;

a power module means, located in said main cabinet means, connectable to an external source of AC power and coupled to said rail means, for providing AC and DC power to said rail means;

a control module, located in said main cabinet means and coupled to both said rail means and the computer means, for controlling communications to and from the computer means and communicating a clock signal on said clock signal conduction means;

at least one function module means, located in said main cabinet means and coupled to said control module and a plurality of mechanical subsystems, for receiving signals indicative of operational conditions of said mechanical subsystems, for generating operational status signals for transmission to said control module means and for generating control signals for controlling the operation of said mechanical subsystems;

first expansion module means located in said main cabinet means and being connected to said rail means and being communicably coupled to said control module via said rail means;

an expansion cabinet means including expansion rail means, said expansion rail means having data conduction means for providing bidirectional data communications along said expansion rail means;

said expansion rail means further including an expansion clock signal conduction means, an expansion AC power conduction means, an expansion DC power conduction means and an expansion ground conduction means;

an expansion power module means located in said expansion cabinet means and connectable to said external source of AC power for providing AC and DC power to said expansion rail means;

at least one function module means located in said expansion cabinet means for receiving signals indicative of operational conditions of mechanical subsystems, for generating operational status signals for transmission to said control module means and for generating control signals for controlling the operation of the mechanical subsystems;

second expansion module means located in said expansion cabinet means and being connected to said expansion rail means and being communicably coupled to each of said function module means located in said expansion cabinet means via said expansion rail means;

a light weight opto-isolated communication link between said first and second expansion module means, said link providing communication of data and clock signals between said first and second expansion module means so that said at least one function module means located in said expansion cabinet means is operated and controlled in a similar manner as said at least one function module means located in said main cabinet, while electrically isolating said first and second expansion module means from one another.

2. A system as defined in claim 1 wherein said communication link comprises at least two pairs of conductors, each of said first and second expansion module means having means for transmitting and receiving data signals unidirectionally on each of said two pairs of conductors.

3. A system as defined in claim 2 wherein said communication link further comprises a third pair of conductors over which a clock signal is transmitted from said first expansion module means to said second expansion module means.

4. A system as defined in claim 3 wherein said pairs of conductors comprise twisted pairs of approximately #22 AWG insulated wire.

5. A system as defined in claim 2 wherein each of said first and second expansion module means further includes opto-isolating means connected to one end of each pair of conductors in said communication link, said opto-isolating means being located at a receiving end of the pairs of conductors.

6. A building automation system of the type which is controllable by a computer means via a network, said system comprising:

at least one main cabinet means including a rail means having a data conductor means for providing bidirectional data communications;

said rail means further including a clock signal conductor means, at least one power conductor means and a ground conductor means;

a power module means located in said main cabinet means, connectable to an external source of AC power and coupled to said rail means, for providing power to said rail means;

a control module, located in said main cabinet means and coupled to both said rail means and the computer means, for controlling communications to and from the computer means and communicating a clock signal on said clock signal conductor means;

at least one function module means located in said main cabinet means and coupled to said control module and a plurality of mechanical subsystems, for receiving signals indicative of operational conditions of said mechanical subsystems, for generating operational status signals for transmission to said control module means and for generating control signals for controlling the operation of said mechanical subsystems;

first expansion module means located in said main cabinet means and being connected to said rail means and being communicably coupled to said control module via said rail means;

an expansion cabinet means located remotely from said main cabinet, said expansion cabinet means also having a power module means, an expansion rail means including a data conductor means for providing bidirectional data communications, at least one function module means, and a second expansion module means located in said expansion cabinet means and being connected to said expansion rail means and being communicably coupled to each of said function module means in said expansion cabinet means via said expansion rail means;

at least two unidirectional opto-isolated communication links between said first and second expansion module means for transmitting data between said expansion module means, while electrically isolating said expansion module means from one another.

7. A system as defined in claim 6 further including a third unidirectional communication link for transmitting a clock signal from said first to said second expansion module.

8. A system as defined in claim 7 wherein each said communication link comprises a pair of conductors of approximately #22 AWG insulated wire.

9. A system as defined in claim 7 wherein each of said unidirectional communication link comprises a pair of conductors.

10. A system as defined in claim 9 wherein each of said first and second expansion module means further includes opto-isolating means connected to one end of each pair of conductors in said communication link, said opto-isolating means being located at a receiving end of said pair of conductors.