Automatic detection of network hardware connection

• US 5,701,411 A
• Filed: 11/04/1994
• Issued: 12/23/1997
• Est. Priority Date: 11/04/1994
• Status: Expired due to Term

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Information Systems Incorporated (Canon Inc.)
• Inventors: Tran, Duc, Russell, William C., Wadsworth, Robert D., Ip, Tony K.
• Primary Examiner(s): Harvey, Jack B.
• Assistant Examiner(s): Myers, Paul R.
• Application Number:
  US08/336,662
• Time in Patent Office: 1,145 Days
• Field of Search: 395/828, 395/824, 395/835, 395/200.02, 395/200.2, 395/821, 395/200.1, 370/13, 370/10
• US Class Current: 709/250
• CPC Class Codes: G06F 13/4022 using switching circuits, e.g. switching matrix, connection or expansion network G06F13/4009 takes precedence

Abstract

A network communication device has plural different connectors, each connectable to a network, and is capable of automatically selecting between the different connectors for network communication. A selector responsive to a selection signal selects one of the plural connectors, and a plurality of detectors, each associated with a corresponding connector, detects whether its corresponding connector is connected to the network. A processor executes a selection process by outputting a selection signal so as to select, in turn, each of the plural different connectors starting with a first connector, maintaining the state of the selection signal in a case where the detector associated with the selected connector indicates connection to the network, cycling to the next connector in a case where the detector does not indicate connection to the network, and repeating the selection process in a case where said processor has cycled through all of said plural connectors.

Claims

1. A network communication device having plural different connectors, each connectable to a network, said device being capable of automatically selecting one of said different connectors for network communication, comprising:

a selector responsive to a selection signal which selects one of the plural different connectors in accordance with the selection signal;

a plurality of detectors, each detector associated with a corresponding connector, and each of which detects whether the corresponding connector is connected to the network before the network communication device effects network communication over the corresponding connector;

a processor which executes a selection process by outputting a selection signal so as to select, in turn, each of the plural different connectors starting with a first connector, maintaining a state of the selection signal in a case where the detector associated with the selected connector indicates connection to the network, cycling to a next connector in a case where the detector does not indicate connection to the network, and repeating the selection process in a case where said processor has cycled through all of said plural different connectors until it is determined that one of the plural connectors is connected to the network.

2. A network communication device according to claim 1, wherein the processor effects network communication over a selected connector after the processor determines which connector is connected to the network.

3. A network communication device according to claim 1, wherein said plural different connectors comprise at least an RJ-45 connector capable of accepting a 10Base-T connection and a BNC connector capable of accepting a 10Base-2 connection.

4. A network communication device according to claim 3, wherein said plurality of different detectors comprise at least a first detector for detecting whether the RJ-45 connector is connected to the network and a second detector for detecting whether the BNC connector is connected to the network.

5. A network communication device according to claim 4, wherein said first detector detects whether there is an electrical current at the RJ-45 connector.

6. A network communication device according to claim 5, further comprising a first detection register which is set to a first state in a case where said first detector detects an electrical current at the RJ-45 connector and to a second state in a case where said first detector does not detect an electrical current at the RJ-45 connector.

7. A network communication device according to claim 4, wherein said second detector detects whether the BNC connector is improperly terminated.

8. A network communication device according to claim 7, further comprising a second detection register which is set to a first state in a case where said second detector detects that the BNC connector is not improperly terminated and to a second state in a case where said second detector detects that the BNC connector is improperly terminated.

9. A network communication device according to claim 4, further comprising:

a first detection register which is set to a first state in a case where said first detector detects that the RJ-45 connector is connected to the network and to a second state in a case where said first detector detects that the RJ-45 connector is not connected to the network; and

a second detection register which is set to a first state in a case where said second detector detects that the BNC connector is connected to the network and to a second state in a case where said second detector detects that the BNC connector is not connected to the network.

10. A network communication device according to claim 9, wherein said processor executes the selection process by outputting a selection signal so as to select the RJ-45 connector, reading said first detection register, maintaining the state of the selection signal in a case where said first detection register is in the first state, outputting a selection signal so as to select the BNC connector in a case where said first detection register is in the second state, reading said second detection register, maintaining the state of the selection signal in a case where said second detection register is in the first state and repeating the selection process in a case where the second detection register is in the second state.

11. A network communication device according to claim 10, wherein network communications are transferred between said processor and the selected connector.

13. A method according to claim 11, further comprising the step of effecting network communication over a selected connector after it is determined which connector is connected to the network.

19. A network communication device according to claim 1, wherein the processor effects network communication over a selected connector after the processor determines which connector is connected to the network.

12. A method for automatically selecting which connector among plural different connectors on a network communication device is connected to a network, comprising the steps of:

outputting a selection signal so as to select, in turn, each of the plural different connectors starting with a first connector;

detecting whether each of the plural different connectors is connected to the network using plural detectors, each of the plural detectors corresponding to a respective one of the plural different connectors and detecting whether the respective one of the plural different connectors is connected to the network before the network communication device effects network communication over the respective one of the plural different connectors;

maintaining the state of the selection signal in a case where the detecting step determines that the selected connector is connected to the network;

cycling to a next connector in a case where the detecting step determines that the selected connector is not connected to the network; and

repeating said outputting, detecting, maintaining and cycling steps in a case where said cycling step has cycled through all of said plural different connectors until it is determined that one of the plural connectors is connected to the network.

14. A method according to claim 12, wherein said plural different connectors comprise at least an RJ-45 connector capable of accepting a 10Base-T connection and a BNC connector capable of accepting a 10Base-2 connection.

15. A method according to claim 14, further comprising the steps of:

determining whether the RJ-45 connector is connected to the network by determining whether there is an electrical current at the RJ-45 connector; and

determining whether the BNC connector is connected to the network by determining whether the BNC connector is improperly terminated.

16. A method according to claim 15, further comprising the steps of:

setting a first detection register to a first state in a case where the RJ-45 connector is connected to the network and to a second state in a case where said first detector detects that the RJ-45 connector is not connected to the network; and

setting a second detection register to a first state in a case where said second detector detects that the BNC connector is connected to the network and to a second state in a case where said second detector detects that the BNC connector is not connected to the network.

17. A method according to claim 16, further comprising the step of:

transferring network communications between the selected connector and a processor on the network communication device.

18. A network communication device having at least first and second connectors, each connectable to a network, comprising:

a network controller connected to the first and second connectors and including a selector responsive to a selection signal for selecting between said first and second connectors, said network controller being connected to a bus, and transferring network communications between said bus and the selected one of said first and second connectors, said network controller also including a first detector for detecting whether said first connector is electrically connected to the network, a second detector for detecting whether the second connector is connected to the network and for outputting a jabber bit indicative of an improper connection of the second connector, the first and second detectors detecting connections of the first and second connectors, respectively, before the network communication device effects network communication over the first and second connectors, and a first register readable through the bus and in which said network controller stores the jabber bit output by said second detector;

a second register readable through the bus for storing a good-link bit indicative of said first detector detecting that the first connector is electrically connected to the network;

a control register writable through the bus for outputting a selection signal in accordance with a select bit stored therein; and

a processor, connected to the bus, which sends and receives network communication over the bus, and which executes a selection process by (1) writing a select bit through the bus to the control register so as to cause output of a selection signal which selects the first connector, (2) reading the good-link bit through the bus from the second register, (3) maintaining the state of the selection bit in the case where the good-link bit indicates electrical connection to the network, (4) writing a select bit through the bus to the control register so as to cause output of a selection signal which selects the second connector in a case where the good-link bit does not indicate electrical connection to the network, (5) reading the jabber bit through the bus from the first register, (6) maintaining the state of the select bit in a case where the jabber bit does not indicate improper electrical termination of the second connector, and (7) repeating the selection process in a case where the jabber bit indicates improper electrical termination of the second connector and the good-link bit does not indicate good electrical connection, the repeating step repeating the selection process until it is determined that one of the connectors is connected to the network.

20. A network communication device according to claim 18, wherein said first connector is an RJ-45 connector capable of accepting a 10Base-T connection and said second connector is a BNC connector capable of accepting a 10Base-2 connection.

21. A network communication device according to claim 20, wherein said processor, in executing the selection process, reads the good-link bit through the bus from the second register a predetermined plurality of times so as to cause a delay, and maintains the state of the selection bit in a case where the good-link bit indicates electrical connection to the network after any of the plurality of reads.