Multiplex circuit arrangement, particularly for the actuation of load stations in motor vehicles

• US 5,313,460 A
• Filed: 04/10/1992
• Issued: 05/17/1994
• Est. Priority Date: 11/06/1989
• Status: Expired due to Fees

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Schmid, Johann
• Primary Examiner(s): Chin, Wellington
• Application Number:
  US07/839,771
• Time in Patent Office: 767 Days
• Field of Search: 370/94.3, 370/94.1, 370/94.2, 370/85.1, 370/85.13, 370/85.14, 370/85.2, 370/85.1, 340/825.5, 340/825.51
• US Class Current: 370/438
• CPC Class Codes: B60R 16/0315 using multiplexing techniques multiplexing for transmission of signals G08C15/00; multiplexing for electrical communication in general H04J
• CPC Class Codes: H04L 12/44 Star or tree networks

Abstract

In a multiplex circuit arrangement, particularly for actuating load stations in motor vehicles, with the circuit including a bus system, an arrangement secure against malfunctions is realized in that the end of each data line (L_D) is provided with a bidirectional bus coupling network (station network SN and distributor network VN) including two oppositely connected analog amplifiers (OP1, OP2), with at least a plurality of central bus coupling networks (distributor networks VN) being combined into a star-shaped central bus distributor arrangement (ZVA).

Claims

1. A multiplex circuit arrangement, particularly for the actuation of load stations in motor vehicles, with each station including a hardware processor for the rapid serial exchange of data and a driver circuit, the multiplex circuit arrangement comprising a bus system operating with an active voltage level and a passive voltage level and with the individual load stations being connected together by a network structure of line sections each including a data line and a load line, and wherein:

each end of each said data line is provided with a respective bidirectional bus coupling network, including a bus coupling station network at a respective said end of a data line connected to a station and a distributor network at the other said end of a respective said data line;

each said coupling network comprises a first analog amplifier and a second analog amplifier which is oppositely connected with said first analog amplifier; and

at least a plurality of central ones of said bus coupling distributor networks are combined into a central bus distributor arrangement.

2. A multiplex circuit arrangement according to claim 1, wherein the line sections to the individual load stations are configured as asymmetrical, two-wire lines.

3. A multiplex circuit arrangement according to claim 1, wherein at least one sub-distributor arrangement, including a further plurality of said bus coupling distributor networks connected in a star-configuration, is connected between one of said at least a plurality of central ones of said bus coupling distributor networks and the bus coupling station network of each of a plurality of stations to provide for the data-load distribution.

4. A multiplex circuit arrangement according to claim 1, wherein each said first analog amplifier, which acts as impedance converter, has an input which is connected to a signal input of the respective said coupling network and an output which is connected via a matching resistor to the associated respective said data line.

5. A multiplex circuit arrangement according to claim 1, wherein, as a protective measure against short circuits to ground, an output of the said second analog amplifier of a respective said coupling network is connected via a first diode to a signal input of said first analog amplifier of said respective said coupling network.

6. A multiplex circuit arrangement according to claim 5, wherein each said bus coupling distributor network is provided with a protective circuit against short circuits to a positive level including a transistor having a controlled current path connected in series with a second diode between said output of the respective said second analog amplifier and ground, and an RC integrator circuit having an input connected to the output of said respective said second analog amplifier and an output connected to a control input of said transistor, whereby the transistor short circuits a static HIGH voltage level signal to ground as a function of the time constant of the integrator.

7. A multiplex circuit arrangement according to claim 6, further comprising a series connection of a resistor and a third diode connected in parallel with the resistor of said RC integrator circuit.

8. A multiplex circuit arrangement according to claim 1 wherein said plurality of central ones of said bus coupling distributor networks are combined into a star-shaped central bus distributor arrangement.

9. A multiplex circuit arrangement according to claim 8, wherein each said first analog amplifier, which acts as impedance converter, has an input which is connected to a signal input of the respective said coupling network and an output which is connected via a matching resistor to the respective said data line.

10. A multiplex circuit arrangement according to claim 9, wherein, as a protective measure against short circuits to ground, an output of the respective said second analog amplifier is connected via a first diode to said signal line of the respective said coupling network.

11. A multiplex circuit arrangement according to claim 10, wherein each said distributor network is provided with a further protective circuit against short circuits to a positive level including a transistor having a controlled current path connected in series with a second diode between said output of the respective said second analog amplifier and ground, and an RC integrator circuit having an input connected to the output of said respective said second analog amplifier and an output connected to a control input of said transistor, whereby the transistor short circuits a static HIGH voltage level signal to ground as a function of the time constant of the integrator circuit.

12. A multiplex circuit arrangement according to claim 8, wherein load fuses for the load lines of the respective line sections connected at said central bus distributor arrangement are provided in said central distributor arrangement.