Computer to fieldbus control system interface

• US 6,304,934 B1
• Filed: 10/13/1995
• Issued: 10/16/2001
• Est. Priority Date: 10/13/1995
• Status: Active Grant

• Current Assignee: Smar Research Corp.
• Original Assignee: Smar Research Corp.
• Inventors: Prizon, Delcio, Paravela, Claudene Jr., Campos, Lellis Do Amaral Jr., Pimenta, Alexandre, Zanarotti, Geraldo Sergio
• Primary Examiner(s): Lefkowitz, Sumati
• Application Number:
  US08/542,591
• Time in Patent Office: 2,195 Days
• Field of Search: 710/126-130, 710/62-74
• US Class Current: 710/305
• CPC Class Codes: G05B 19/042 using digital processors G05B19/05 takes precedence
• CPC Class Codes: G05B 2219/25006 Interface connected to fieldbus
• CPC Class Codes: G05B 2219/25428 Field device

Abstract

An interface device for interfacing a computer to a Fieldbus control system thereby allowing the computer to configure, control, and monitor components such as sensors and actuators which are coupled to the Fieldbus. The interface device connects to a serial port of the computer and to a Fieldbus, providing the necessary formatting of data and conditioning of signals exchanged between the Fieldbus and the computer. The interface device is powered entirely or partially from the computer via the serial port and thus does not further load a Fieldbus to which it is connected. The interface device is also portable and is thus well suited for interfacing a portable computer to a Fieldbus system in the control room or the field, e.g., close to the Fieldbus components to be monitored or controlled.

Claims

1. An interface device for interfacing a computer with a Fieldbus, comprising:

a serial port connector for connecting the interface device to a serial port of the computer;

a power supply coupled to the serial port connector for generating, from power supplied by the computer, a stabilized DC voltage for powering the interface device;

a processor coupled to the serial port connector for processing data from the computer and the Fieldbus for communication to the Fieldbus and the computer, respectively; and

a medium attachment unit (MAU) coupled to the processor for connecting to the Fieldbus and for providing predetermined electrical characteristics for signals transmitted to and received from the Fieldbus.

2. The interface device of claim 1, comprising a modem coupled between the processor and the MAU for modulating data from the processor for transmission over the Fieldbus and for demodulating signals from the Fieldbus for processing by the processor.

3. The interface device of claim 2, comprising a housing for housing the interface device, wherein the housing is smaller than 6 inches by 6 inches by 6 inches.

4. The interface device of claim 3, wherein the serial port of the computer is an RS-232 serial port.

5. The interface device of claim 1, wherein the interface device draws substantially zero power from the Fieldbus.

6. The interface device of claim 1, wherein the processor includes a serial communications device which is coupled to the serial port connector for communicating with the computer.

7. The interface device of claim 1, wherein the processor includes an electrically erasable programmable read-only memory (EEPROM).

8. The interface device of claim 7, comprising a driver coupled between the serial port connector and the processor for conditioning signals communicated between the interface device and the computer.

9. The interface device of claim 8, comprising an oscillator for generating clock signals for the processor and the modem.

10. The interface device of claim 7, wherein the processor is packaged in a single integrated circuit.

11. The interface device of claim 10, wherein the processor executes software during operation, the software being maintained in the EEPROM when power is discontinued.

12. The interface device of claim 7, comprising two clip-on connectors for connecting the interface device to the Fieldbus.

13. The interface device of claim 1, wherein the interface device is only partially powered from the Fieldbus.

14. The interface device of claim 1, wherein the processor includes a nonvolatile programmable memory.

15. The interface device of claim 14, wherein the nonvolatile memory is flash memory.

16. An interface device for interfacing a computer with a Fieldbus, comprising:

a serial port connector for connecting the interface device to a serial port of the computer;

a processor coupled to the serial port connector for processing data from the computer and the Fieldbus for communication to the Fieldbus and the computer, respectively;

a medium attachment unit (MAU) coupled to the processor for connecting to the Fieldbus and for providing predetermined electrical characteristics for signals transmitted to and received from the Fieldbus;

a modem coupled between the processor and the MAU for modulating data from the processor for transmission over the Fieldbus and for demodulating signals from the Fieldbus for processing by the processor; and

a housing for housing the interface device, wherein the housing is smaller than 5 inches by 6 inches by 1.5 inches.

17. The interface device of claim 16, wherein the processor includes:

nonvolatile means for storing a program to be executed by the processor.

18. The interface device of claim 17, further comprising:

a power supply coupled to the serial port connector for generating, from power supplied by the computer, a stabilized DC voltage for powering the interface device.

19. An interface device for interfacing a computer with a Fieldbus, comprising:

a serial port connector for connecting the interface device to a serial port of the computer;

means for generating, from power supplied by the computer, a stabilized DC voltage for powering the interface device coupled to the serial port connector;

a processor coupled to the serial port connector for processing data from the computer and the Fieldbus for communication to the Fieldbus and the computer, respectively; and

a modem coupled to the processor for modulating data from the processor for transmission over the Fieldbus and for demodulating signals from the Fieldbus for processing by the processor.