JPH08130545A - Switching controller for bus type transmission equipment - Google Patents

Abstract

PURPOSE: To provide a switching controller having simple constitution, low cost and high reliability by constituting an interface for a node connected to plural transmission lines of a common controller and controlling data transmission by the switching information of transmission lines. CONSTITUTION: In a transmission equipment duplex transmission lines for instance, an interface for a node 1 connects a controller 7 to a CPU 2 through an internal bus 6, connects a system switching part 10 to the controller 7 and connects transmission lines 4a, 4b to the switching part 10 respectively through modems 8a, 8b and drivers/receivers 9a, 9b. The CPU 2 inputs a system state signal and a system switching command signal from respective modems 8a, 8b, executes arithmetic processing based upon these signals and outputs a system switching request signal and a system switching command signal to control data transmission. Since it is unnecessary for an OS driver of a unit CPU to be conscious of the duplication of transmission lines, the constitution can be simplified and control can be executed only by one transmission controller.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bus type transmission device which is effective for transmission switching in a bus type LAN.

[0002]

2. Description of the Related Art In a bus type LAN such as Ethernet or map (MAP), there is only one transmission line. In other words, if the transmission line is broken or the transceiver fails, the node is in a transmission-disabled state. To avoid this, the transmission system should be duplicated.

In a bus type transmission device having dual transmission lines,
The cost is doubled, and the transmission control program (operating system driver) becomes complicated. For this reason, there are few systems in which the transmission line is duplicated in the bus type LAN. As a few examples, there are a loop type transmission line type and a bus type duplicated transmission line. In the case where the transmission line type is the loop type, the transmission line is duplicated by the loopback method.

Further, in a conventional transmission device having a dual transmission line, the transmission interface is as shown in FIG. That is, in FIG. 5, 6 is an internal bus and 7a and 7b.
Is a controller, 8a and 8b are modems, 9a and 9b are drivers / receivers, and the node 1 is duplicated via the internal bus 6.

[0005]

As described above, in the system configuration of FIG. 4, the cost is high and the number of interfaces is two. Therefore, the CP for controlling it is required.
The operating system drivers in U become very complex.

Further, in a transmission device having dual transmission lines, when one interface supports two transmission lines, the configuration of the transmission unit in the interface is as shown in FIG. 5, and the controller is The cost is high because it is expensive, and the control of two controllers is controlled by one CPU (microcomputer etc.) when the transmission speed is high.
However, it was not reliable because the process could not catch up.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a switching control device for a bus type transmission device which has a simple structure, low cost and high reliability.

[0008]

In order to achieve the above object, a switching control device for a bus type transmission device according to the present invention comprises:
At least one common node connected to the 1-system transmission path and the 2-system transmission path includes an interface and an arithmetic processing unit, and the 1-system transmission is performed based on information guided to the arithmetic processing unit via the interface. In a bus type transmission device that controls switching between a transmission path and a 2 system transmission path,
A 1-system modem that guides information of the 1-system transmission line to the arithmetic processing unit and processes the command signal from the arithmetic processing unit as an input; and guides information of the 2-system transmission line to the arithmetic processing unit and performs the calculation. A system 2 modem for processing the command signal from the processing unit as an input, and a system switching command signal from the system 1 modem and the system 2 modem and a system switching command signal from the arithmetic processing unit as input to the system 1 transmission line and the system 2 transmission. It is characterized in that it is constituted by a system switching circuit for switching a path and a transmission controller for controlling data transmission based on switching information of the system switching circuit.

That is, the structure of the transmission section of the transmission interface is improved so that one controller is provided and a system switching section is added under the controller. Software (firmware) in the CPU and memory monitors the status of the 1st / 2nd systems and selects a usable system.

[0010]

Embodiments of the present invention will be described below with reference to FIGS.

FIG. 3 shows a transmission device in which transmission lines are duplicated according to an embodiment of the present invention. Reference numeral 1 denotes a node, which has a central processing unit (CPU) 2 and an interface 3.

In the transmission interface 3 of the transmission device shown in FIG. 3, as shown in FIG. 2, one controller 7 is connected to the CPU 2 via the internal bus 6, and the system switching unit 10 is connected to the controller 7. The system switching unit 10 is connected to the 1-system transmission line 4a via the modem 8a and the driver / receiver 9a, and is connected to the 2-system transmission line 4b via the modem 8b and the driver / receiver 9b. Has been done.

As shown in FIG. 1, the transmission interface 3 comprises an input register 11, an output register 12, a system switching circuit 10, a 1-system modem 13a, a 2-system modem 13b, drivers 14a and 14b, and receivers 15a and 15b. ing. More specifically, the transmission controller 7, the input register 11 and the output register 12 are connected to the CPU 2 via the internal bus 6, and the transmission controller 7
The system switching circuit 10 is connected to the output register 12. The system switching circuit 10 is connected to the 1-system modems 13a and 13b, and the controller 7 is connected to the 1-system modems 13a and 13b.
Is connected. 1 series modem 13a and 2 series modem 13
b is connected to the input register 11 and the output register 12, respectively, the 1-system modem 13a is connected to the 1-system transmission line 4a via the driver 14a or the receiver 15a, and the 2-system modem 13b is connected to the driver 14b or the receiver 15b. It is connected to the second system transmission line 4b via the.

In the bus type transmission device having the above-mentioned configuration, FIG.
As shown in FIG. 2, the CPU 2 has system status signals RDY1, RDY.
2 and system switching instructing signals CIND1 and CIND2 as input, and performing arithmetic processing based on these signals, system switching request signals CREQ1 and CREQ2 and system switching command signal SEL
Is output. That is, the 1-system modem 13a receives the 1-system transmission path normal signal RDY1 indicating that the 1-system transmission data is the same as the 1-system reception data, and the fact that the other node has notified the 2-system abnormality, and the result is "1". Then, the 1-system switching instruction signal RDY2, which is a signal that becomes, is input to the CPU 2 via the input register 11. The system 2 modem 13b indicates that the system 2 transmission line normal signal R indicates that the system 2 transmission data is the same as the system 2 reception data.
The DY2 and the 2-system switching instruction signal CIND2 which becomes "1" upon receiving the notification of the 1-system abnormality by the other node are input to the CPU2 via the input register 11. The CPU 2 performs arithmetic processing on the basis of these signals to perform the system 1 modem 13a.
In addition, via the output register 12, the 1-system switching request signal CREQ output to the 1-system transmission line when the own node detects the 2-system abnormality
1 and a 2 system switching request signal CREQ2, which is a signal to be sent to the 2 system transmission line when its own node detects the 1 system abnormality, is output to the 2 system modem 13b via the output register 12. Also,
SEL is a system switching signal that designates the receiving system of its own node. SEL = 0 is the 1 system, and SEL = 1 is the 2 system. Here, CREQ1 and CREQ2 are notified to other nodes as CIND1 and CIND2 through the transmission path, and this signal is added to the transmission frame and transmitted.

In the normal state, RDY1 = 1 (one system is normal),
RDY2 = 1 (2 system normal), CIND1 = 0 (1 system switching instruction not given), CIND2 = 0 (2 system switching instruction not given). From this state, the system switching process is executed according to the change of the input signal. The correspondence of the output signal to the input signal is as shown in Table 1.

[0016]

[Table 1]

In Table 1, "*" mark and "-" indicate that there is no signal. For example, when both systems are abnormal, RDY1 = 0,
If RDY2 = 0, and if there is an error in the local station 1 system, RDY1
= 0, RDY2 = 1, CIND1 = 0, CIND2 =
0, CREQ1 = 0, CREQ2 = 1, and SEL = 1. Further, for example, when both systems are normal, RDY1 = 1,
RDY2 = 1, CIND1 = 0, CIND2 = 0, CR
EQ1 = 0, CREQ2 = 0, and SEL = 0.

As described above, the embodiments of the present invention can be summarized as follows.

(1). A single transmission interface can be used for dual transmission lines.

(2). A single transmission controller is placed in the transmission interface to realize redundant transmission lines.

(3). RDY1, RDY2, CIND
1, CIND2 input signal, CREQ1, CREQ
2. The system is switched by the SEL output signal.

(4). CREQ1 and CREQ2 shall be notified to other nodes as CIND1 and CIND2 via the transmission line.

(5). CPU (microcomputer) for system switching
What the firmware does. In this case, it is also possible to implement by hardware.

[0024]

The present invention is as described above, and the transmission line duplication can be realized at a low cost, and the OS driver of the unit CPU does not need to be aware of the duplication of the transmission line, so that it can be simplified. In addition, since there is only one transmission controller, it is cost effective. Further, since there is only one transmission controller, a CPU for controlling the transmission controller even if the transmission speed increases.
It can be supported without making the (microcomputer) so fast, and the system can be easily switched depending on the state of the transmission path.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration inside an interface of a switching control device of a bus type transmission device according to an embodiment of the present invention.

FIG. 2 is a block diagram of a switching control device of a bus type transmission device according to an embodiment of the present invention.

FIG. 3 is a schematic configuration diagram of a bus type transmission device used in an embodiment of the present invention.

FIG. 4 is a schematic configuration diagram of a conventional bus type transmission device.

FIG. 5 is a block diagram of a conventional switching control device for a bus type transmission device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Node 2 ... Arithmetic processing part 2a ... Memory 3 ... Interface (I / F) 4a, 4b ... Transmission path 5a, 5b ... Transceiver 10 ... Transmission controller 11 ... Input register 12 ... Output register 13a ... 1 system modem 13b ... 2 System modems 14a, 14b ... Drivers 15a, 15b ... Receivers

Claims (1)

[Claims] 1. At least one common node connected to the 1-system transmission line and the 2-system transmission line includes an interface and an arithmetic processing unit, and based on information guided to the arithmetic processing unit via the interface. A bus type transmission device for controlling switching between the 1-system transmission path and the 2-system transmission path, wherein the interface section guides information of the 1-system transmission path to the arithmetic processing section and a command signal from the arithmetic processing section. 1 system modem for processing as input, and 2 system modem for guiding information of the 2 system transmission path to the operation processing unit and processing command signal from the operation processing unit as input, 1 system modem and 2 system A system switching circuit for switching between the 1-system transmission path and the 2-system transmission path by inputting a processing signal of a modem and a system switching command signal from the arithmetic processing section, and data based on switching information of the system switching circuit. Characterized by being constituted by a transmission controller for controlling the transmission, switching controller of the bus-type transmission apparatus.