CA2425080A1 - Protection switching of interface cards in communication system - Google Patents
Protection switching of interface cards in communication system Download PDFInfo
- Publication number
- CA2425080A1 CA2425080A1 CA002425080A CA2425080A CA2425080A1 CA 2425080 A1 CA2425080 A1 CA 2425080A1 CA 002425080 A CA002425080 A CA 002425080A CA 2425080 A CA2425080 A CA 2425080A CA 2425080 A1 CA2425080 A1 CA 2425080A1
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- Prior art keywords
- interface card
- card
- primary
- coupled
- communication
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04M—TELEPHONIC COMMUNICATION
- H04M3/00—Automatic or semi-automatic exchanges
- H04M3/005—Interface circuits for subscriber lines
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04M—TELEPHONIC COMMUNICATION
- H04M2201/00—Electronic components, circuits, software, systems or apparatus used in telephone systems
- H04M2201/38—Displays
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04M—TELEPHONIC COMMUNICATION
- H04M3/00—Automatic or semi-automatic exchanges
- H04M3/08—Indicating faults in circuits or apparatus
- H04M3/12—Marking faulty circuits "busy"; Enabling equipment to disengage itself from faulty circuits ; Using redundant circuits; Response of a circuit, apparatus or system to an error
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04M—TELEPHONIC COMMUNICATION
- H04M3/00—Automatic or semi-automatic exchanges
- H04M3/18—Automatic or semi-automatic exchanges with means for reducing interference or noise; with means for reducing effects due to line faults with means for protecting lines
Abstract
ABSTRACT
A communication system includes primary and secondary interface cards. A
switching circuit allows both of the interface cards to selectively communicate over a medium without inducing reflection. Further, an automatic detection system is provided to allow a management circuit to identify which interface card is coupled as the primary or secondary card.
A communication system includes primary and secondary interface cards. A
switching circuit allows both of the interface cards to selectively communicate over a medium without inducing reflection. Further, an automatic detection system is provided to allow a management circuit to identify which interface card is coupled as the primary or secondary card.
Description
PROTECTION SWITCHING OE rNTERFACE CARDS
IN COMMUNICATION SYSTEM
FfFLD OF THE INYENT10N
[0001) The present invention relates generally to communication systems and in particular the present invention relates to interface card for communication systems.
BACKGROUND OF TH>r TNVENTION
IN COMMUNICATION SYSTEM
FfFLD OF THE INYENT10N
[0001) The present invention relates generally to communication systems and in particular the present invention relates to interface card for communication systems.
BACKGROUND OF TH>r TNVENTION
[0002] Communication system often contains two interface cards to provide transceiver functions over a medium, such at a coaxial cable. The two cards include a primary card 101 and a protection card 102, see Figure I. The primary card 101 contains a medium control switch I03, which couplesldecouples its transceiver to a communication medium 105. Protection card 102 also contains a medium control switch I04, which couplesldecouplcs its transceiver to the telecommunication medium I05. Under normal operating conditions, the medium control switch 103 is ON
and the primary card is coupled to the communication medium and performs communication functions. The protection card is in a "hot" standby mode with its medium control switch 104 turned OFF.
and the primary card is coupled to the communication medium and performs communication functions. The protection card is in a "hot" standby mode with its medium control switch 104 turned OFF.
[0003] As soon as a manage-ment card has determined a failun: on the primary card, switch 103 is turned OFF and switch 104 is turned 4N. The protection card then takes over communication traffic. The primary and protection cards are typically located physically distanced one from another. As such, the communication medium, such as a coaxial cable, is split into two cables 106 and 107. While cable 106 is connected to transceiver 101 through switch I03 and is properly terminated, cable 107 is floating"
because switch 104 is OFF. $ecause cards 101 and 102 are two separate entities, floating cable 107 must have some length, that causes reflection of signs!
back into communication medium 1 OS. This can cause data transfer errors because the communication signals in the medium 105 get distorted.
7 00.303US01 [0004] To reduce reflection to a sustainable level, the maximum length of the floating cable is limited. This limitation, however, restricts the design of the interface cards. As bandwidth of the signal in the cable gets wider, the length of the floating cable must decrease. Because the floating cable cannot have a xero length, the data rate of the communication equipment is limited.
because switch 104 is OFF. $ecause cards 101 and 102 are two separate entities, floating cable 107 must have some length, that causes reflection of signs!
back into communication medium 1 OS. This can cause data transfer errors because the communication signals in the medium 105 get distorted.
7 00.303US01 [0004] To reduce reflection to a sustainable level, the maximum length of the floating cable is limited. This limitation, however, restricts the design of the interface cards. As bandwidth of the signal in the cable gets wider, the length of the floating cable must decrease. Because the floating cable cannot have a xero length, the data rate of the communication equipment is limited.
[0005] For the reasons stated above, and for other reasons stated below which will become apparent to those skilled in the art upan reading and understanding the prnsent specifccation, there is a need in the art for a more flexible interface card for communication system.
SUI~1MARY OF THE TNV'ENTION
[000!'7 The above-mentioned problems with communication system and other problems arc addressed by the grcscnt invention and will be understood by reading and studying the following specification_ [0007] Xtt one embodiment. a communication system comprises a communication medium, a switch circuit, a primary interface card coupled to the communication medium via the switch circuit, and a secondary interFace card coupled to the switch circuit. The secondary interface card controls the switch circuit to decouple the primary interface card from the communication medium and couple the secondary interface card to the communication medium via the switch circuit.
[0008] A communication system comprises a communication medium, a switch circuit including a relay, a first interface card coupled to the communication medium via the switch circuit, and a second interface card coupled to the relay and switch circuit. The second interface card controls the relay to decouple the first interface card from the communication medium and couple the second interface card to the communication medium via the switch circuit. A management card is coupled to the first and second interface cards and selectively activates either the f rst or second interface card and determines if the first or second interface card is coupled to the relay_ 100.303US01 [0009] A method of operating a communication system comprises installing a primary interface card, installing a secondary interface card, selectively activating the primary interface card using a management card, monitoring a current load of the activated primary interface card, identifying the activated primary interface card based upon the monitored current load, and storing the identification information.
l3RrFF DESCRIPTION OF THE DRAWINGS
[0010] Figure l is a block diagram of a prior art interface card communication system;
[00X1] Figure 2 is a block diagram of an cinuodiment of an interface card communication system of the present invention;
(0012] Figure 3 is a schematic diagram of circuitry included in an interface card of an embodiment of the present invention; and [0013] Figure 4 illustrates a telecommunication systeTri of an embodiment of the present invention.
DETAILED DESCRIPTION OF TETr? DRAWINGS
[0014] In the following detailed description of the preferred embodiments, reference is made to the accompanying drawings, which form a part hereof, and in which is shown by way of illustration specific preferred embodiments in which the inventions may be practiced. These embodiments arc described in sufficient detail to enable those skilled in the art to practice the invention, and it is to be understood that other embodiments may be utilized and that logical, mechanical and electrical changes may be made without departing from the spirit and scope of the present invention. The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of the present invention is defined only by the claims.
(0015) As explained above, prior communication system (see Figure 1) eont<-dns two interface cards, the primary 101 and the protection 102. Under normal operating 100.303US01 conditions, the primary card is coupled to communication medium 105 via medium control switch 103. In response to a detected failure of the primary card, protection card 102 is coupled to medium 105 via medium control switch 104 and switch 103 is turned OFF. When switch 104 is OFF, cable 107 causes reflection of signal back into communication medium 105. An embodiment of the present invention changes the switching structure of the interface card and medium connections.
[OOZE] Referring to Fgure 2, an embodiment of the present invention contains a primary interface card 20l , a protection, or secondary, card 202, a management card 200 and a single medium control switch 206. The primary and secondary cards get selectively coupled to communication medium 205 connection of the medium control switch 206. It will be appreciated that the communication mediums can be any electrical or optical medium used for communication, such as but not linuted to coaxial cable and fibre optics.
[0017] Medium control switch 206 includes a switch circuit 210 to selectively couple medium 205 to cards 201 or 202 through cables 203 or 204. Using one switch allows cables 203 and 204 to be any length and does not result in reflection on medium 205. Protection card 202 controls operation of switch 206 by activating a relay 226.
Under normal conditions, switch 210 connects medium 205 (position 209) to the primary card 201 through the medium 203. If management card 200 determines that a failure on the primary card 201 has occurred, the protection card turns switch 210 to position 208 to connect the protection card 202 to medium 205. Medium 205 gets properly terminated either on the primary card 201 under nomlal conditions or on the protection card 202 after being switched to it. The proposed solution eliminates a floating cable and the limitations on card design associated with it [0018] Primary card 201 has output node 303 and input node 304 that arc coupled to a light-emitted diode (I:ED) 220 and current limiting resistor 224. When the primary card is activated by an activation signal at input 306 from the management card, LED
220 is illuminated. The management card can determine if card 201 or card 202 is 100.303US01 coupled as the primary card, as explained in detail below, by using output nodes 307 and 308.
[0019] The above embodiment of the present invention reduires one medium control switch as opposed to two switches necessary for prior systems.
Typically, cards 201 and 202 ate the same by design. One of them is considered primary and another becomea a protection card. Each card includes relay contml circuitry and feedback circuitry. ReFen-ing to Figure 3, an embodiment of relay control circuitry 301 and feedback circuitry 302 is described. Input node 306 receives an activation signal from the management card, and output nodes 307 and 308 are coupled to provide feedback to the management card. During an evaluation operation; either during troublahootins or at initialization, the management card activates node 306 (high voltage).
Input transistor 404 is connected to node 306 through resistor 409. A current-limiting resistor 408 is coupled to transistor switch 403. When transistor 404 is activated, transistor 403 is activated and node 303 is pulled high. Lode 303 is coupled to either an LED
or an j F1~ and relay. Feedback circuit 302 is used to identify the card as either a primary (LED only) or a secondary (LED and relay).
[0020] Feedback circuit 302 contains two eompar-~tors S06 and 507, and current sensor resistor 501. First inputs of comparators are connected to current sensor resistor 501 through a balance resistor 502. Second inputs of comparators are connected to voltage rcfccenccs, for instance, a resistor divider circuit 503, 504, 505. If thet~e is no current conducted through resistor 501, a voltage on the first inputs of the compar3tors is lower than reference voltage applied to their second input As a result, bath eomparators output logic ZERO indicating no current through the Load connected to 303 and 304. If the card is connected to an LED, the voltage drop across resistor activates compatator 507, but not comparator 506. If the card is coupled to an LED 'and the switch relay 226, the voltage drop across resistor 501 activates comparator 507 and comparator 506.
[0021] In addition to identifying the primary and secondary cards, the management card, or external processor, can determine if nodes 303 and 304 are broken or shorted.
100.303US01 S
If there is no connection between nodes 303 and 304, a voltage across resistor 50I is OV
and both comparators output logic ZERO. Tf node 303 is shorted to either node 304 or ground, then transistor 403 is turned OFF and a voltage across resistor 501 is also OV.
[0022] If node 303 is shorted, the can eat conducted through resistor 401 provides a voltage drop across resistor 401 that is sufficient to turn ON safety transistor 402.
When transistor 402 turns ON, transistor 403 is partially turned off. Resistor 407 helps to further reduce current through transistor 403_ A voltage drop across resistor 405 is added to the voltage across resistor 401 to turn ON transistor 402 and to turn transistor 403 OFF_ As such, safety transistor 402 toms off transistor 403 when the currant through resistor 401 is above a threshold level.
[0023] Because the management card "doesn't know" which interface card is connected as a primary or prateccion, an evaluation operation is performed by turning transistor 404 ON and monitoring the feedback. ZF a low current load is detected, the evaluated card is determined to be connected as a primary card. IC a high current load is detected, the evaluated card is determined to be connected as a protection card. When a protection card is detected, the management card turns transistor 404 O~
immediately to prevent the switching of relay 226. The management card stores identification information about the primary and protection status of the cards. The management card can then inform a technician what equipment slot contains the primary card and what equipment slot contains the protection card. The management card can also switch from the primary to the protection card as soon as a failure on the primary card has been detected. It will be appreciated by those skilled in the art with the benefit of the present invention that the management card can implement any failureJdefect monitoring and identification method without depaning from the present invention.
[0024] Figure 4 illustrates a communication system of an embodiment of the present invention. The system includes client locations 420 that are coupled to communicate with remote transceiver stations 430. Transceiver stations 430 opet~.te as relay stations to coordinate the communication between the clients and a central station 440. All of the locations are coupled together using one or more communication media 100.303US01 450. As such, both the remote and central station can include primary and secondary intrsfacc cards, as described above. For example, the central station X40 has numerous cards 460 that are coupled to a back plane (not shown) for communication with the remote stations.
Conclusion [0025] A communication system has been described that includes primary and secondary interface cards. A switching circuit allows both of the interface cards to selectively communicate over a medium without inducing reflection. Further, an automatic detection system is provided to allow a management circuit to identify which inuerface card is coupled as the primary or secondary card.
[0026] Although specific embodiments have been illustrated and described herein, is will be appreciated by those of ordinary skill in the art that any arrangement, which is calculated to achieve the same purpose, may be substituted for the specific embodiment shown. This application is intended to cover any adaptations or variations of the present invention. Therefore, it is manifestly intended that this invention be limited only by the claims and the equivalents thereof.
SUI~1MARY OF THE TNV'ENTION
[000!'7 The above-mentioned problems with communication system and other problems arc addressed by the grcscnt invention and will be understood by reading and studying the following specification_ [0007] Xtt one embodiment. a communication system comprises a communication medium, a switch circuit, a primary interface card coupled to the communication medium via the switch circuit, and a secondary interFace card coupled to the switch circuit. The secondary interface card controls the switch circuit to decouple the primary interface card from the communication medium and couple the secondary interface card to the communication medium via the switch circuit.
[0008] A communication system comprises a communication medium, a switch circuit including a relay, a first interface card coupled to the communication medium via the switch circuit, and a second interface card coupled to the relay and switch circuit. The second interface card controls the relay to decouple the first interface card from the communication medium and couple the second interface card to the communication medium via the switch circuit. A management card is coupled to the first and second interface cards and selectively activates either the f rst or second interface card and determines if the first or second interface card is coupled to the relay_ 100.303US01 [0009] A method of operating a communication system comprises installing a primary interface card, installing a secondary interface card, selectively activating the primary interface card using a management card, monitoring a current load of the activated primary interface card, identifying the activated primary interface card based upon the monitored current load, and storing the identification information.
l3RrFF DESCRIPTION OF THE DRAWINGS
[0010] Figure l is a block diagram of a prior art interface card communication system;
[00X1] Figure 2 is a block diagram of an cinuodiment of an interface card communication system of the present invention;
(0012] Figure 3 is a schematic diagram of circuitry included in an interface card of an embodiment of the present invention; and [0013] Figure 4 illustrates a telecommunication systeTri of an embodiment of the present invention.
DETAILED DESCRIPTION OF TETr? DRAWINGS
[0014] In the following detailed description of the preferred embodiments, reference is made to the accompanying drawings, which form a part hereof, and in which is shown by way of illustration specific preferred embodiments in which the inventions may be practiced. These embodiments arc described in sufficient detail to enable those skilled in the art to practice the invention, and it is to be understood that other embodiments may be utilized and that logical, mechanical and electrical changes may be made without departing from the spirit and scope of the present invention. The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of the present invention is defined only by the claims.
(0015) As explained above, prior communication system (see Figure 1) eont<-dns two interface cards, the primary 101 and the protection 102. Under normal operating 100.303US01 conditions, the primary card is coupled to communication medium 105 via medium control switch 103. In response to a detected failure of the primary card, protection card 102 is coupled to medium 105 via medium control switch 104 and switch 103 is turned OFF. When switch 104 is OFF, cable 107 causes reflection of signal back into communication medium 105. An embodiment of the present invention changes the switching structure of the interface card and medium connections.
[OOZE] Referring to Fgure 2, an embodiment of the present invention contains a primary interface card 20l , a protection, or secondary, card 202, a management card 200 and a single medium control switch 206. The primary and secondary cards get selectively coupled to communication medium 205 connection of the medium control switch 206. It will be appreciated that the communication mediums can be any electrical or optical medium used for communication, such as but not linuted to coaxial cable and fibre optics.
[0017] Medium control switch 206 includes a switch circuit 210 to selectively couple medium 205 to cards 201 or 202 through cables 203 or 204. Using one switch allows cables 203 and 204 to be any length and does not result in reflection on medium 205. Protection card 202 controls operation of switch 206 by activating a relay 226.
Under normal conditions, switch 210 connects medium 205 (position 209) to the primary card 201 through the medium 203. If management card 200 determines that a failure on the primary card 201 has occurred, the protection card turns switch 210 to position 208 to connect the protection card 202 to medium 205. Medium 205 gets properly terminated either on the primary card 201 under nomlal conditions or on the protection card 202 after being switched to it. The proposed solution eliminates a floating cable and the limitations on card design associated with it [0018] Primary card 201 has output node 303 and input node 304 that arc coupled to a light-emitted diode (I:ED) 220 and current limiting resistor 224. When the primary card is activated by an activation signal at input 306 from the management card, LED
220 is illuminated. The management card can determine if card 201 or card 202 is 100.303US01 coupled as the primary card, as explained in detail below, by using output nodes 307 and 308.
[0019] The above embodiment of the present invention reduires one medium control switch as opposed to two switches necessary for prior systems.
Typically, cards 201 and 202 ate the same by design. One of them is considered primary and another becomea a protection card. Each card includes relay contml circuitry and feedback circuitry. ReFen-ing to Figure 3, an embodiment of relay control circuitry 301 and feedback circuitry 302 is described. Input node 306 receives an activation signal from the management card, and output nodes 307 and 308 are coupled to provide feedback to the management card. During an evaluation operation; either during troublahootins or at initialization, the management card activates node 306 (high voltage).
Input transistor 404 is connected to node 306 through resistor 409. A current-limiting resistor 408 is coupled to transistor switch 403. When transistor 404 is activated, transistor 403 is activated and node 303 is pulled high. Lode 303 is coupled to either an LED
or an j F1~ and relay. Feedback circuit 302 is used to identify the card as either a primary (LED only) or a secondary (LED and relay).
[0020] Feedback circuit 302 contains two eompar-~tors S06 and 507, and current sensor resistor 501. First inputs of comparators are connected to current sensor resistor 501 through a balance resistor 502. Second inputs of comparators are connected to voltage rcfccenccs, for instance, a resistor divider circuit 503, 504, 505. If thet~e is no current conducted through resistor 501, a voltage on the first inputs of the compar3tors is lower than reference voltage applied to their second input As a result, bath eomparators output logic ZERO indicating no current through the Load connected to 303 and 304. If the card is connected to an LED, the voltage drop across resistor activates compatator 507, but not comparator 506. If the card is coupled to an LED 'and the switch relay 226, the voltage drop across resistor 501 activates comparator 507 and comparator 506.
[0021] In addition to identifying the primary and secondary cards, the management card, or external processor, can determine if nodes 303 and 304 are broken or shorted.
100.303US01 S
If there is no connection between nodes 303 and 304, a voltage across resistor 50I is OV
and both comparators output logic ZERO. Tf node 303 is shorted to either node 304 or ground, then transistor 403 is turned OFF and a voltage across resistor 501 is also OV.
[0022] If node 303 is shorted, the can eat conducted through resistor 401 provides a voltage drop across resistor 401 that is sufficient to turn ON safety transistor 402.
When transistor 402 turns ON, transistor 403 is partially turned off. Resistor 407 helps to further reduce current through transistor 403_ A voltage drop across resistor 405 is added to the voltage across resistor 401 to turn ON transistor 402 and to turn transistor 403 OFF_ As such, safety transistor 402 toms off transistor 403 when the currant through resistor 401 is above a threshold level.
[0023] Because the management card "doesn't know" which interface card is connected as a primary or prateccion, an evaluation operation is performed by turning transistor 404 ON and monitoring the feedback. ZF a low current load is detected, the evaluated card is determined to be connected as a primary card. IC a high current load is detected, the evaluated card is determined to be connected as a protection card. When a protection card is detected, the management card turns transistor 404 O~
immediately to prevent the switching of relay 226. The management card stores identification information about the primary and protection status of the cards. The management card can then inform a technician what equipment slot contains the primary card and what equipment slot contains the protection card. The management card can also switch from the primary to the protection card as soon as a failure on the primary card has been detected. It will be appreciated by those skilled in the art with the benefit of the present invention that the management card can implement any failureJdefect monitoring and identification method without depaning from the present invention.
[0024] Figure 4 illustrates a communication system of an embodiment of the present invention. The system includes client locations 420 that are coupled to communicate with remote transceiver stations 430. Transceiver stations 430 opet~.te as relay stations to coordinate the communication between the clients and a central station 440. All of the locations are coupled together using one or more communication media 100.303US01 450. As such, both the remote and central station can include primary and secondary intrsfacc cards, as described above. For example, the central station X40 has numerous cards 460 that are coupled to a back plane (not shown) for communication with the remote stations.
Conclusion [0025] A communication system has been described that includes primary and secondary interface cards. A switching circuit allows both of the interface cards to selectively communicate over a medium without inducing reflection. Further, an automatic detection system is provided to allow a management circuit to identify which inuerface card is coupled as the primary or secondary card.
[0026] Although specific embodiments have been illustrated and described herein, is will be appreciated by those of ordinary skill in the art that any arrangement, which is calculated to achieve the same purpose, may be substituted for the specific embodiment shown. This application is intended to cover any adaptations or variations of the present invention. Therefore, it is manifestly intended that this invention be limited only by the claims and the equivalents thereof.
Claims (26)
1. A communication system comprising:
a switch circuit;
a primary interface card couplable to a communication medium connection via the switch circuit; and a secondary interface card coupled to the switch circuit, wherein the secondary interface card controls the switch circuit to decouple the primary interface card from the communication medium connection and couple the secondary interface card to the communication medium connection via the switch circuit.
a switch circuit;
a primary interface card couplable to a communication medium connection via the switch circuit; and a secondary interface card coupled to the switch circuit, wherein the secondary interface card controls the switch circuit to decouple the primary interface card from the communication medium connection and couple the secondary interface card to the communication medium connection via the switch circuit.
2. The communication system of claim 1 further comprising a management card coupled to the primary and secondary cards, wherein the management card instructs the secondary interface card to operate the switch circuit to decouple the primary interface card.
3. The communication system of claim 1 wherein the primary and secondary cards each include circuitry to output signals that identify if the card is primary or secondary.
4. The communication system of claim 1 wherein the primary card is coupled to illuminate a light emitting diode (LED) when the primary card is operational, wherein the illuminated LED determines a current load of the primary card.
5. The communication system of claim 4 wherein the secondary card is coupled to illuminate a light emitting diode and activate a relay when the secondary card is operational, wherein the illuminated LED and activated relay determine a current load of the secondary card.
6. The communication system of claim 5 further comprising a management card coupled to the primary and secondary cards, wherein the management card monitors the current loads of the primary and secondary cards to identify the cards.
7. A communication system comprising:
a communication medium;
a switch circuit including a relay;
a first interface card coupled to the communication medium via the switch circuit;
a second interface card coupled to the relay and switch circuit, wherein the second interface card controls the relay to decouple the first interface card from the communication medium and couple the second interface card to the communication medium via the switch circuit;
a management circuit coupled to the first and second interface cards, wherein the management circuit selectively activates either the first or second interface card and determines if the first or second interface card is coupled to the relay.
a communication medium;
a switch circuit including a relay;
a first interface card coupled to the communication medium via the switch circuit;
a second interface card coupled to the relay and switch circuit, wherein the second interface card controls the relay to decouple the first interface card from the communication medium and couple the second interface card to the communication medium via the switch circuit;
a management circuit coupled to the first and second interface cards, wherein the management circuit selectively activates either the first or second interface card and determines if the first or second interface card is coupled to the relay.
8. The communication system of claim 7 wherein the management circuit monitors a current load of the first and second interface card to determine if the first or second interface card is coupled to the relay.
9. the communication system of claim 7 wherein the management circuit activates the second interface card in response to an operational defect of the first interface card.
10. A communication system comprising:
a switch circuit including a light emitting diode (LED) and a relay;
an interface card coupled to the switch circuit, the interface card comprising, a relay control circuit coupled to selectively activate the relay, the relay control circuit is further coupled to illuminate the LED, and a feedback circuit to monitor a current load of the relay control circuit and provide output signals; and a management circuit coupled to the interface card, wherein the management circuit selectively activates the relay control circuit and monitors the output signal of the feedback circuit.
a switch circuit including a light emitting diode (LED) and a relay;
an interface card coupled to the switch circuit, the interface card comprising, a relay control circuit coupled to selectively activate the relay, the relay control circuit is further coupled to illuminate the LED, and a feedback circuit to monitor a current load of the relay control circuit and provide output signals; and a management circuit coupled to the interface card, wherein the management circuit selectively activates the relay control circuit and monitors the output signal of the feedback circuit.
11. The communication system of claim 10 wherein the relay control circuit compasses:
a switch transistor coupled to source current to the LED and relay;
an input transistor coupled to selectively activate the switch transistor, and first and second comparator circuits coupled to compare a current conducted through the switch transistor with first and second references, respectively.
a switch transistor coupled to source current to the LED and relay;
an input transistor coupled to selectively activate the switch transistor, and first and second comparator circuits coupled to compare a current conducted through the switch transistor with first and second references, respectively.
12. The communication system of claim 11 wherein the relay control circuit further comprises a safety circuit to deactivate the switch transistor if the relay control circuit is shorted.
13. A method of operating a communication system comprising:
installing a primary interface card;
installing a secondary interface card;
selectively activating the primary interface card using a management card;
monitoring a current load of the activated primary interface card;
identifying the activated primary interface card based upon the monitored current load; and storing the identification information.
installing a primary interface card;
installing a secondary interface card;
selectively activating the primary interface card using a management card;
monitoring a current load of the activated primary interface card;
identifying the activated primary interface card based upon the monitored current load; and storing the identification information.
14. The method of claim 13 wherein the primary interface card current load is defined by a current through a light-emitting diode (LED) coupled to the primary interface card.
15. The method of claim 13 further comprising:
selectively activating the secondary interface card using a management card;
monitoring a current load of the activated secondary interface card;
identifying the activated secondary interface card based upon the monitored current load; and storing the identification information.
selectively activating the secondary interface card using a management card;
monitoring a current load of the activated secondary interface card;
identifying the activated secondary interface card based upon the monitored current load; and storing the identification information.
16. The method of claim 15 wherein the secondary interface card current load is defined by a current through a light-emitting diode (LED) and a relay circuit coupled to the secondary interface card.
17. A method of identifying an interface card comprising:
activating the interface card;
comparing a current load of the interface card to first and second references;
identifying the interface card as either a primary card or a secondary card based upon the comparison; and storing data indicating the result of the identification.
activating the interface card;
comparing a current load of the interface card to first and second references;
identifying the interface card as either a primary card or a secondary card based upon the comparison; and storing data indicating the result of the identification.
18. The method of claim 17 wherein the secondary card operates a switch relay circuit and has a higher current load than a current load of the primary card.
19. A method of operating a communication system comprising:
coupling a primary interface card to a communication medium via a switch;
detecting an operational error of the primary card;
decoupling the primary interface card from the communication medium; and coupling a secondary interface card to the communication medium via the switch.
coupling a primary interface card to a communication medium via a switch;
detecting an operational error of the primary card;
decoupling the primary interface card from the communication medium; and coupling a secondary interface card to the communication medium via the switch.
20. The method of claim 19 wherein the secondary interface card controls the switch.
21. The method of claim 19 wherein a management card detects the operational error of the primary card and instructs the secondary card to activate the switch to decouple the primary interface card from the communication medium and couple the secondary interface card to the communication medium.
22. A communication switch circuit comprising:
a primary card indicator to provide a visual indication when a primary interface card is operably coupled to the communication switch circuit;
a secondary card indicator to provide a visual indication when a secondary interface card is operably coupled to the communication switch circuit; and a switch circuit relay coupled to the secondary interface card, such that the switch circuit relay selectively couples either the primary or secondary interface card to a communication medium connection in response to a signal from the secondary interface card.
a primary card indicator to provide a visual indication when a primary interface card is operably coupled to the communication switch circuit;
a secondary card indicator to provide a visual indication when a secondary interface card is operably coupled to the communication switch circuit; and a switch circuit relay coupled to the secondary interface card, such that the switch circuit relay selectively couples either the primary or secondary interface card to a communication medium connection in response to a signal from the secondary interface card.
23. The communication switch circuit of claim 22 wherein the primary and secondary card indicators are light emitting diodes (LEDs).
24. A communication interface card comprising:
a relay control circuitry to provide an output signal to a communication switch circuit; and a feedback circuit coupled to the communication switch circuit to monitor a load current of the communication interface card through the communication switch circuit.
a relay control circuitry to provide an output signal to a communication switch circuit; and a feedback circuit coupled to the communication switch circuit to monitor a load current of the communication interface card through the communication switch circuit.
25. The communication interface card of claim 24 wherein the relay control circuitry comprises:
a switch transistor to couple a voltage source to an output node to provide the output signal; and an input transistor coupled to activate the switch transistor in response to an externally provided activation signal.
a switch transistor to couple a voltage source to an output node to provide the output signal; and an input transistor coupled to activate the switch transistor in response to an externally provided activation signal.
26. The communication interface card of claim 24 wherein the feedback circuit comprises:
a current sensor resistor coupled to an input node;
a first comparator to compare a voltage drop across the current sensor resistor with a first reference voltage; and a second comparator to compare the voltage drop across the current sensor resistor with a second reference voltage.
a current sensor resistor coupled to an input node;
a first comparator to compare a voltage drop across the current sensor resistor with a first reference voltage; and a second comparator to compare the voltage drop across the current sensor resistor with a second reference voltage.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US10/119,483 US6978395B2 (en) | 2002-04-10 | 2002-04-10 | Protection switching of interface cards in communication system |
| US10/119,483 | 2002-04-10 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2425080A1 true CA2425080A1 (en) | 2003-10-10 |
Family
ID=28789933
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002425080A Abandoned CA2425080A1 (en) | 2002-04-10 | 2003-04-10 | Protection switching of interface cards in communication system |
Country Status (2)
| Country | Link |
|---|---|
| US (1) | US6978395B2 (en) |
| CA (1) | CA2425080A1 (en) |
Families Citing this family (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7054264B2 (en) * | 2001-07-24 | 2006-05-30 | Corrigent Systems Ltd. | Interconnect and gateway protection in bidirectional ring networks |
| US7061859B2 (en) * | 2001-08-30 | 2006-06-13 | Corrigent Systems Ltd. | Fast protection in ring topologies |
| US7032135B2 (en) * | 2002-08-02 | 2006-04-18 | Corrigent Systems Ltd. | Equipment protection using a partial star architecture |
| US7283465B2 (en) * | 2003-01-07 | 2007-10-16 | Corrigent Systems Ltd. | Hierarchical virtual private LAN service protection scheme |
| US7551850B2 (en) * | 2003-05-15 | 2009-06-23 | International Business Machines Corporation | Highly available redundant optical modules using single network connection |
| US7974223B2 (en) | 2004-11-19 | 2011-07-05 | Corrigent Systems Ltd. | Virtual private LAN service over ring networks |
| CN100382526C (en) * | 2005-09-08 | 2008-04-16 | 华为技术有限公司 | Main/stand by alternation method between links in access-in network system |
| US7983150B2 (en) * | 2006-01-18 | 2011-07-19 | Corrigent Systems Ltd. | VPLS failure protection in ring networks |
| US7808931B2 (en) | 2006-03-02 | 2010-10-05 | Corrigent Systems Ltd. | High capacity ring communication network |
| US7660303B2 (en) | 2006-08-22 | 2010-02-09 | Corrigent Systems Ltd. | Point-to-multipoint functionality in a bridged network |
| US7660234B2 (en) * | 2006-09-22 | 2010-02-09 | Corrigent Systems Ltd. | Fault-tolerant medium access control (MAC) address assignment in network elements |
| US8862904B2 (en) * | 2008-06-25 | 2014-10-14 | Intel Corporation | Techniques for distributed management of wireless devices with shared resources between wireless components |
Family Cites Families (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5226120A (en) * | 1990-05-21 | 1993-07-06 | Synoptics Communications, Inc. | Apparatus and method of monitoring the status of a local area network |
| US5712754A (en) * | 1996-04-15 | 1998-01-27 | Compaq Computer Corporation | Hot plug protection system |
| US6512774B1 (en) * | 1999-03-18 | 2003-01-28 | 3Com Corporation | Fail over with multiple network interface cards |
| US6639894B1 (en) * | 2000-05-03 | 2003-10-28 | Metro-Optix, Inc. | Communications interconnect with make-before-break signal routing |
| US6636478B1 (en) * | 2000-05-03 | 2003-10-21 | Metro Optix, Inc. | Configurable scalable communications equipment protection method system |
| US6763479B1 (en) * | 2000-06-02 | 2004-07-13 | Sun Microsystems, Inc. | High availability networking with alternate pathing failover |
| US6757748B1 (en) * | 2000-07-20 | 2004-06-29 | Rlx Technologies, Inc. | Modular network interface system and method |
| US20020176355A1 (en) * | 2001-05-22 | 2002-11-28 | Alan Mimms | Snooping standby router |
| US20030035408A1 (en) * | 2001-08-17 | 2003-02-20 | Hebert James E. | Redundant communication adapter system for connecting a client to an FDDI network |
-
2002
- 2002-04-10 US US10/119,483 patent/US6978395B2/en not_active Expired - Fee Related
-
2003
- 2003-04-10 CA CA002425080A patent/CA2425080A1/en not_active Abandoned
Also Published As
| Publication number | Publication date |
|---|---|
| US20030196135A1 (en) | 2003-10-16 |
| US6978395B2 (en) | 2005-12-20 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EEER | Examination request | ||
| FZDE | Discontinued |
Effective date: 20140131 |