Methods and systems for interfacing with an interface powered I/O device

• US 5,909,586 A
• Filed: 11/06/1996
• Issued: 06/01/1999
• Est. Priority Date: 11/06/1996
• Status: Expired due to Term

• Current Assignee: Schneider Electric Systems USA, Inc. (Schneider Electric SE)
• Original Assignee: The Foxboro Company (Schneider Electric SE)
• Inventors: Anderson, Daniel Joseph
• Primary Examiner(s): Sheikh, Ayaz R.
• Assistant Examiner(s): Etienne, Ario
• Application Number:
  US08/744,785
• Time in Patent Office: 937 Days
• Field of Search: 395/750.01, 395/750.02, 395/750.08, 395/750.07, 395/281, 395/282, 395/283, 395/284, 395/882, 395/828, 395/830
• US Class Current: 713/340
• CPC Class Codes: G05B 19/0423 Input/output
• CPC Class Codes: G05B 2219/21016 I-O has own power supply
• CPC Class Codes: G05B 2219/21103 Connect pc to machine, controller, module via PCMCIA
• CPC Class Codes: G05B 2219/25148 Before communication, check if I-O is powered
• CPC Class Codes: G05B 2219/25359 Special power supply

Abstract

An I/O device powered by its computer interface is interfaced to a computer through a PC Card. A dongle is included with a cable assembly between the PC Card and the I/O device. Power for the I/O device is supplied thereto by an external power supply connected to the dongle. Using a power status input, the PC card can detect whether the external power supply is operational and connected, and accordingly, the PC Card manages operations with the I/O device.

Claims

1. A computer interface couplable to an interface powered Input/Output ("I/O") device, said computer interface comprising:

a PC Card, said PC Card including input-output circuitry and at least one power status input;

a power source, external to said PC Card, for powering said I/O device; and

a cable assembly adapted to connect said PC Card and said power source to said I/O device, wherein said cable assembly couples said power source to said at least one power status input such that a power status of said power source is detectable by said PC Card.

2. The computer interface of claim 1, wherein said cable assembly includes a dongle.

3. The computer interface of claim 2, wherein said dongle includes a power input for connection to said power source.

4. The computer interface of claim 3, wherein said dongle includes a power status output and a power supply output, said power status output being connected to said at least one power status input of said PC Card through said cable assembly and said power supply output being connected to said I/O device through said cable assembly.

5. The computer interface of claim 4, wherein said dongle includes a filter and a surge suppresser, and wherein said power input is connected to said filter and to said surge suppresser.

6. The computer interface of claim 4, wherein said dongle includes a switching element having a control input, and wherein said power input is coupled to said control input of said switching element, said switching element being connected between said power status output of said dongle and a ground.

7. The computer interface of claim 6, wherein said dongle includes a voltage regulator, and wherein said power input is coupled to said control input of said switching element through said voltage regulator.

8. The computer interface of claim 7, wherein said switching element comprises a transistor, said control input comprises a base of said transistor, and an output of said voltage regulator is coupled to said base of said transistor through at least one resistor.

9. The computer interface of claim 7, wherein said dongle includes logic circuitry, and wherein an output of said voltage regulator is connected to at least one power supply input of said logic circuitry within said dongle.

10. The computer interface of claim 4, wherein said power input is directly connected to said power supply output.

11. The computer interface of claim 2, wherein said dongle includes a clock buffer circuit connected between a clock output of said PC Card and a clock input of said I/O device through said cable assembly.

12. The computer interface of claim 1, wherein said I/O device comprises a GE FANUC Field Control I/O system, and wherein said cable assembly is adapted to plug into a control module connector on said I/O device.

13. A method of interfacing a PC Card to an Input/Output ("I/O") device, said I/O device being powered by a power supply external to said PC Card, wherein a cable assembly connects said PC Card, said I/O device and said power supply, and wherein said method comprises:

(a) initializing said PC Card;

(b) said PC Card checking a condition indicated by at least one power status line received on said cable assembly, said condition being indicative of a status of said power supply;

(c) if said at least one power status line indicates an unpowered condition, repeating said checking step (b) until said power status line indicates a powered condition; and

(d) when said powered condition is detected by said PC Card, said PC Card initializing communications with said I/O device.

14. The method of claim 13, wherein said initializing (a) includes asserting a reset signal directed to said I/O device over said cable.

15. The method of claim 14, further comprising deactivating said reset signal after said at least one power status line indicates said powered condition.

16. The method of claim 15, wherein after said deactivating said reset signal, said method includes said PC Card initializing said I/O device.

17. The method of claim 16, wherein after said initializing said I/O device, said method includes beginning operational communications between said PC Card and said I/O device.

18. The method of claim 17, wherein said method further includes, during said operational communications, said PC Card monitoring said power status line to detect said unpowered condition.

19. The method of claim 18, wherein if said unpowered condition is detected during said operational communications with said I/O device, said method includes indicating said unpowered condition to a host computer to which said PC Card is connected.

20. The method of claim 18, wherein if said unpowered condition is detected during said operational communications with said I/O device, said method includes asserting said reset signal.

21. The method of claim 18, wherein if said unpowered condition is detected during said operational communications with said I/O device, said method includes said PC Card monitoring said power status line awaiting detection of said powered condition.

22. The method of claim 21, wherein when said powered condition is restored, said method includes deactivating said reset signal.

23. The method of claim 21, wherein when said powered condition is restored, said method includes indicating said powered condition to a host computer to which said PC Card is connected.

24. The method of claim 21, wherein when said powered condition is restored, said method further includes deactivating said reset signal, indicating said powered condition to a host computer to which said PC Card is connected, said PC Card initializing said I/O device, and resuming operational communications between said PC Card and said I/O device.

25. An Input/Output ("I/O") system comprising:

an I/O subsystem comprising a chassis having at least one module receiving location, a first module receiving location of said at least one module receiving location adapted to receive an I/O type module, said I/O subsystem also including a connector adapted to couple with a control module that would power said I/O subsystem;

a PC Card;

a power source, external to said PC Card, for powering said I/O subsystem; and

a cable assembly interconnecting said PC card, said power source and said connector of said I/O subsystem.

26. The I/O system of claim 25, wherein said I/O subsystem comprises a GE FANUC Field Control I/O system.

27. The I/O system of claim 25, wherein said cable assembly includes an internal dongle.

28. The I/O system of claim 27, wherein said internal dongle includes a power input for connection to said power source through said cable assembly.

29. The I/O system of claim 28, wherein said internal dongle includes power supply circuitry for interfacing said PC Card, said I/O subsystem and said power source.

30. The I/O system of claim 29, wherein said internal dongle includes buffer circuitry for interfacing said PC Card to said I/O Subsystem.