JPH03220935A - Duplicate switching control system - Google Patents

Abstract

PURPOSE:To quicken the changeover of active and standby cards in the occurrence of a fault by using a data recognition section of the standby card designated by an address so as to recognize a duplicate changeover data thereby switching the standby card into the active card. CONSTITUTION:When an active card 3(4) has a fault, a status data representing the occurrence of the fault is set to a card status section 10 and when a start bit detection section 6 detects a start bit of a polling signal, a bus access section 7 is started. Then a duplicate switching data is sent to a response bus 5 while an address of a standby card 4(3) set to a physical address setting section 9. A data recognition section 8 of the standby card 4(3) recognizes the data to be the duplicate switching data designating its own card, the standby card is selected into the active card. Thus, the changeover control between the active and the standby cards is implemented by the occurrence of a fault independently of the polling period.

Description

[Detailed Description of the Invention] [Summary] Regarding a duplex switching control method in a duplex configuration device such as a data transmission device, the purpose is to speed up the switching between active and backup in the event of a failure, and to control each part. In a device with a duplex configuration, a device control card accesses multiple sets of working and spare cards by polling via a control bus, and a response signal is sent from the accessed card to the device control card via a response bus. , the card is provided with a start bit detection section, a bus access section, a data recognition section, and a physical address setting section, and when a failure occurs in the current card, the control from the device control card is performed in the current card. The start bit of the polling signal sent to the bus is detected by the start bit detection section, and the bus access section sends out duplex switching data to which the address set in the physical address setting section is added via the response bus. The spare card specified by the address is configured so that the data recognition unit in the spare card recognizes the duplex switching data and controls switching from the spare to the active card.

[Industrial application field]

The present invention relates to a duplex switching control system in a duplex configuration device such as a data transmission device.

A card having an integrated circuit or the like mounted on a printed circuit board is inserted into a slot to form a shelf, and this shelf is inserted into a rack to form a device such as a data transmission device. The cards include a device control card that controls each part, and active and standby cards that control data transmission and reception between lines, and the device control card controls switching between the active and standby modes. In devices with such a duplex configuration, there is a demand for faster switching between active and standby devices when a failure occurs.

[Prior Art] FIG. 4 is an explanatory diagram of a conventional example, in which 41 is a device control card, 42 is a clock bus, 43 is a control bus, 44 is a response bus, 45, 46 are current and spare cards, 47. 4
8 is a control data receiving section, 49.degree. 50 is a card status section, and 51 is a data bus. Although only two cards 45 and 46 are shown, more cards 45 and 46 may be mounted.

The device control card 41 manages whether each card is in use or in reserve, and performs switching control between the in-use and stand-by cards by detecting the occurrence of a failure. A clock signal is sent from this device control card 41 to a clock bus 42, and a polling signal is sent to a control bus 43 in synchronization with this clock signal.

The card designated as the active card by the device control card 41 will transmit and receive data to and from the data bus 51. Further, the cards 45 and 46 set status data indicating whether each part is normal or abnormal using a self-diagnosis function or the like in the card status section 49 or 50. Also clock bus 42
Based on the clock signal from the control data receiving section 47.4
At step 8, the polling signal transmitted via the control bus 43 is received, it is determined whether the polling address is the address of the own card, and if it is the address of the own card, the polling signal is set in the card status section 49. Send status data to response bus 44.

Therefore, since the device control card 41 can read the status data of each card by polling,
It is possible to identify whether each card is normal or abnormal, and control is performed to switch to a spare card if the current card is abnormal. Further, each card is controlled according to control data included in the polling signal, such as switching between active and standby cards.

FIG. 5 is an explanatory diagram of the operation of the conventional example, showing an example of signals in the clock bus, control bus, and response bus.
A clock signal from the device control card 41 is transmitted to the clock bus 42, and a control bus 43 and a response bus 44
At this time, a signal of m step synchronization is transmitted. That is, the control bus 43 contains the start bit S from the device control card 41 and the slot address (slot position within the shelf).
A physical address consisting of a shelf address (shelf position in the rack), control data such as a status data sending command, a working/standby switching command, and a parity bit P is transmitted. The card that received this polling signal sends a message to the response bus 44.
A response signal consisting of a start bit S, status data, and return parity bit RP is sent out.

If the response signal received via the response bus 44 does not include data indicating a failure, the device control card 41 increments the polling address and repeats the above-described operation.

For example, the current card 45. In the case of the spare card 46, if a failure occurs in the working card 45, status data indicating the failure is sent to the card status section 49. When the current card 45 is designated by polling from the device control card 41, status data is sent out as a response signal from the card status section 49.
The device control card 41 identifies that a failure has occurred in the working card 45 based on this status data, controls the working card 45 to switch to the standby side, and specifies the standby card 46 by the polling address to perform control. Control is performed to switch from standby to active based on the data.

[Problem that the invention seeks to solve]

Current use managed by device control card 41.

When the number of spare cards 45, 46 increases, the polling cycle becomes correspondingly longer. Therefore, there is a drawback that it takes a long time until the device control card 41 recognizes the occurrence of a failure in the working card and switches the spare card to the working card.

An object of the present invention is to speed up the switching between the active and standby systems when a failure occurs.

[Means to solve the problem]

The duplex switching control method of the present invention is to perform switching between the working card and the standby card by data transfer between the working card and the standby card when a failure occurs, and will be explained with reference to FIG.

The device control card 1 that controls each part accesses multiple sets of working and spare cards 3.4 via the control bus 2 by polling, and status data is sent from the accessed card to the device control card 1 via the response bus. In the duplex configuration device for sending data, the card 3.4 is provided with a start bit detection section 6, a bus access section 7, a data recognition section 8, and a physical address setting section 9. Reference numeral 10 denotes a card status section for setting status data, and a control data receiving section for receiving control data transmitted via the control bus 2 is not shown.

When a failure occurs in the current card, the start bit detection unit 6 detects the start bit of the polling signal from the device control card l, and the bus access unit 7
from the physical address setting section 9 to the response bus 5.
The redundant switching data with the address set in is sent, and the spare card specified by this address is
The data recognition unit 8 in the spare card recognizes the card and controls switching from the spare card to the active card.

[Effect]

The response signal containing status data is sent to control bus 2.
After receiving and identifying the polling signal transmitted via the polling signal, the response bus 5 is sent to the response bus 5, and the response bus 5 is empty for at least the period from the start bit of the polling signal to the length of the polling signal. There is.

Therefore, when a failure occurs in the current card, status data indicating the occurrence of the failure is set in the card status section 10, and when the start bit detection section 6 detects the start bit of the polling signal, the bus access section 7 is activated. Ru.

Thereby, the address of the spare card set in the physical address setting section 9 is added, and the duplex switching data is sent to the response bus 5.

The spare card recognizes in the data recognition unit 8 that it is the designated duplex switching data, and performs switching control from the spare to the current use. Therefore, regardless of the polling cycle, switching control between active and standby is performed upon occurrence of a failure.

〔Example〕

Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 2 is a block diagram of an embodiment of the present invention, in which 11 is a device control card for managing and controlling each part, 12 is a clock bus, 13 is a control bus, 14 is a response bus, and 20.30
is used for line control, etc.

Spare card, 21. 31 is a control data receiving section, 22.
32 is a card status section, 23.33 is a start bit detection section, 24.34 is a bus access section, 25.35 is a physical address setting section, 26.36 is a data recognition section, and 27.37 is a control section.

If card 20.30 is used as a working and spare set, card 2
A physical address consisting of the slot address and shelf address of the card 30 is set in the physical address setting section 25 of the card 30, and a physical address consisting of the slot address and shelf address of the card 20 is set in the physical address setting section 35 of the card 30. Address is set.

Further, the control data receiving section 21.31 is connected to the device control card 11.
Control data is received from the card status unit 22 via the control bus 13 by polling, and status data is sent from the card status unit 22 to the response bus 14 under the control of the control unit 27 in accordance with the received control data. In addition, status data indicating the presence or absence of a fault in each part is set in the card status section 22.32 by the self-diagnosis function under the control of the control section 27.37. When status data indicating a fault is set, the bus access section 24.34
A start-up signal is added to the start signal.

The start bit detection section 23.33 detects the start bit of the polling signal sent from the device control card 11 to the control bus 13, and the detection signal is applied to the bus access section 24.34. Bus access section 24.3
4 adds a start bit to the beginning of the physical address from the physical address setting section 35 based on the signal from the card status section 22.32 and the detection signal from the start bit detection section 23.33, and adds the current use, Duplex switching data to which a control bit for backup switching has been added is sent to the response bus 14.

Further, the data recognition units 26 and 36 identify whether the duplex switching data on the response bus 14 is addressed to the own card by the physical address, and if it is addressed to the own card, identify the control bit.

The configuration of each part described above can be easily realized by, for example, the data processing function of the processor.

FIG. 3 is an explanatory diagram of the operation of the embodiment of the present invention, and shows an example of signals on the clock bus, control bus, and response bus. A polling signal consisting of a start bit S, a physical address, control data, and a parity bit P is transmitted to the control bus 13 in synchronization with the clock signal of the clock bus 12. When the start bit S is detected, the start bit S and the physical address specifying the spare card,
Duplex switching data consisting of a control bit instructing switching from standby to active is sent to the response bus 14.

In the spare card that has received this data for duplication switching, the data recognition section recognizes it, and the card is switched from the standby to the working card under the control of the control section or the like.

Further, after receiving the polling signal, a response signal consisting of a start bit, status data, and return parity bit RP is sent to the response bus 14 from the card designated by the polling signal.

In this case, since the redundancy switching data is shorter than the polling signal, it does not overlap in time with the response signal, and even if a large number of cards are connected to the response bus 14, the redundancy switching data is shorter than the polling signal. , it is possible to transfer duplex switching data to the spare card paired with it, regardless of the polling cycle.

〔Effect of the invention〕

As explained above, in the present invention, when a failure occurs in the working card, the start bit detection unit 6 polls the redundancy switching data to which the physical address of the spare card set in the physical address setting unit 9 is added. When the start address of the signal is detected, it is sent from the bus access unit 7 to the response bus 5, and the spare card specified by this physical address is
The data recognition unit 8 recognizes this duplex switching data,
This controls switching from standby to active use.

In this case, polling from the device control card 1 is performed in an asynchronous manner, and the response bus 5 is definitely in an empty state during the period of the polling signal, so the start bit of the polling signal is detected and the duplex switching is performed. Even if data is sent to the response bus 5, it will not conflict with response signals from other cards, and since it is not controlled by the device control card 1, it is unrelated to the polling cycle and managed by the device control card 1. Even when a large number of cards are being controlled, it is possible to shorten the switching time between active and standby cards in the event of a failure, and the device control card 1
This has the advantage of reducing the processing load.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of the principle of the present invention, FIG. 2 is a block diagram of an embodiment of the present invention, and FIG. 3 is an explanatory diagram of the operation of an embodiment of the present invention.
FIG. 4 is an explanatory diagram of the conventional example, and FIG. 5 is an explanatory diagram of the operation of the conventional example. 1 is a device control card, 2 is a control bus, 3 and 4 are cards,
5 is a response bus, 6 is a start bit detection section, 7 is a bus access section, 8 is a data recognition section, 9 is a physical address setting section, and 10 is a card status section.

Claims (1)

[Claims] From the device control card (1) that controls each part to the control bus (2)
), a plurality of sets of active and spare cards (3, 4) are accessed by polling, and a response signal is sent from the accessed card to the device control card (1) via a response bus (5). In the device having the following configuration, the card (3, 4) is provided with a start bit detection unit (6).
, a bus access section (7), a data recognition section (8),
A physical address setting unit (9) is provided, and when a failure occurs in the current card, the start bit of a polling signal sent from the device control card (1) to the control bus (2) in the current card is set to the start bit. Detected by the bit detection unit (6) and detected by the bus access unit (6).
7) sends duplex switching data to which the address set in the physical address setting section (9) is added via the response bus (5), and the spare card specified by the address is transferred to the spare card. A duplex switching control method characterized in that the data recognition unit (8) in the duplex switching control system recognizes the duplex switching data and controls switching from standby to active use.