JPH0795259A - Device for switching transmission system - Google Patents

Abstract

PURPOSE:To prevent the load concentration on part of system when systems 4a-4e of a transmission line 5 are switched and used in succession. CONSTITUTION:M number of lines 2a and 2b connected to an information processing part 1 are successively switched and connected to M number of systems from among the N systems in the transmission line 5 having N systems 4a-4e more than the M number of lines. In this case, lines 2a and 2b are switched and connected to a waiting time counter 20 counting the time when the own system is not connected to any of the M number of lines for each N system comprising the transmission line 5 and to the dead systems 4a-4e with the longest idle waiting time TC1-TC4 preserved in the waiting time counter 20 in response to switching commands 15a and 15b for each line.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transmission system switching device used for sequentially switching and using each system of a transmission line.

[0002]

2. Description of the Related Art For example, a transmission line having a plurality of systems between a group of information processing devices arranged in one place and a group of terminal devices or a group of sensors arranged in another place. I am making When the number N of systems installed in this transmission line is set to be larger than the number M of lines formed between each information processing device and the terminal device or the sensor, an abnormality occurs in the line, or one terminal device or one When collecting information from one sensor with a plurality of information processing devices, communication is possible using another system.

In addition, when there are a large number of terminal devices or sensors to be communicated with, each terminal device or sensor may be connected to each system of the transmission line in a one-to-one correspondence. in this way,
When the number N of transmission lines actually attached is larger than the number M of lines on the information processing apparatus side, the state of each system is managed in order to equalize the communication load of each system. In a sense, the system used by each of the M lines is switched to the next system in sequence every time one communication process is completed.

In addition, when the number of terminals or sensors to be communicated is large and each terminal or sensor is connected to each system of the transmission line in a one-to-one correspondence, Even when data is sequentially acquired from each sensor and processed, it is necessary to sequentially switch the connection destination system of each line.

FIG. 4 is a schematic diagram showing a communication system that satisfies the above-mentioned requirements, for example, M information processing devices 1 ₁
.About.1 _M are connected to the transmission system switching device 3 via lines 2 ₁ to 2 _M , respectively. The transmission system switching device 3 transmission line 5 is connected, which is composed of N lines 4 ₁ to 4 _N. Each line 4 ₁ to 4 _N of the transmission line 5 is connected to the switching circuit 6. And. The exchange circuit 6 is connected to _K sensors 8 ₁ to 8 _K via signal lines 7 _{1 to} 7 _K , respectively.

Then, the transmission system switching device 3 connects the M respective lines 2 ₁ to 2 _M connected to the respective information processing devices ₁ to _M of the N systems 4 ₁ to 4 _N of the transmission line 5. Connect to the system. When a switching command is sent from each information processing device 1 via each line 2 ₁ to 2 _M , the connection destination system of the corresponding information processing device 1 is switched to the next free system.

As described above, the transmission system switching device 3 sequentially switches the connection destination system of the corresponding line to the idle systems 4 ₁ to 4 _N each time a switching command is input from each of the information processing measures 1 ₁ to 1 _M. To go.

When sequentially switching the connection destination systems of the respective lines, a method of sequentially switching the systems _{1 1} to _N 4 ₁ to 4 _N in numerical order is generally adopted.
In addition, a priority switching method has been adopted in which priorities are set between the respective lines, and when there are a plurality of empty lines at the time of line switching, the lines are switched to a system having a higher priority.

[0009]

[Problems to be Solved by the Invention] However, The transmission system switching device 3 that sequentially switches each line in the above-described procedure also has the following problems to be improved.
That is, each of the information processing devices 1 ₁ to 1 _M has its own line 2 ₁
The time T required to acquire data from each of the sensors 8 ₁ to 8 _{K of} the communication destination or to exchange various information via 2 _M differs depending on each of the sensors 8 ₁ to 8 _K. Further, it also varies greatly depending on the type of exchange information.

Therefore, for example, a certain information processing device 1 completes a series of communication processes such as data reception and information exchange with one sensor 8 and then communicates with the next sensor 8 by a switching command. Is transmitted to the transmission system switching device 3, but if communication with the other information processing device 1 of the system of the next number is not completed, the line 2 is connected to the relevant system 4.
Cannot be connected, so the corresponding line 2 is connected to the system 4 having the next number.

Then, the information processing device 1 executes communication with the sensor 8 via the system 4 having the next number.
When this communication is completed, connection switching is further attempted for the system 4 having the next number.

As described above, when the switching command is sent from the information processing device 1, if the next system is in use, the system 4 is skipped and the line is connected to the next system.
As a result, in the once skipped system, even if the communication to the other information processing device 1 ends immediately and the system becomes idle, the line is not connected until the connection system makes one round. Therefore, the load state of each system is not uniformed, an excessive communication load occurs in some systems, and a condition in which some systems are barely loaded occurs.

Further, the particular information processing device 1 is less likely to be connected to the particular system 4, and thus the corresponding information processing device 1
However, there is a concern that data cannot be collected from each sensor 8 periodically and evenly.

The present invention has been made in view of the above circumstances, and by providing a waiting time counter for measuring the time in a state where the transmission line is not connected to each line, each line is provided. It is an object of the present invention to provide a transmission system switching device that can equalize the communication load of the above and efficiently perform communication through each system of the transmission path.

[0015]

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention provides transmission with M lines each connected to an information processing section, and N lines larger than the number of M lines. Always connect to M systems of N systems on the road, and connect the connection destination system of each line in response to each switching command input from each information processing unit via each line. In a transmission system switching device that sequentially switches to an idle system that is not in a state, for each N systems that form a transmission line,
The waiting time counter that measures the time when its own system is not connected to any of the M lines, and the waiting time counter that responds to the switching command of each line It is provided with a switching control means for switching the corresponding line to an empty system having a long waiting time.

[0016]

In the transmission system switching device configured as described above, the time during which each line constituting the transmission line is not connected to any line, that is, the waiting time until the next line is connected TC is timed by a latency counter. Then, when a switching command is input from the information processing unit of each line, the corresponding line is switched and connected to the system having the longest waiting time TC at this point. Therefore, a system with an extremely long waiting time does not occur, and the communication load of each system can be made uniform.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a schematic configuration of a transmission system switching device of the embodiment. The overall schematic diagram of the communication system incorporating the embodiment transmission system switching device is almost the same as the conventional communication system shown in FIG.

It should be noted that, in the communication system in which this embodiment transmission system switching device is incorporated, two information processing devices 1 (M =
2), and the number of systems 4 constituting the transmission line 5 is 5 (N =
5).

In FIG. 1, the line 2a of the information processing apparatus 1 on one side (A side) of the two information processing apparatuses 1 is connected to the common terminal c of the switching circuit 12a and the receiving section 13a via one connection terminal 11a. Is input to. Similarly, the line 2 of the other (B side) information processing device 1 of the two information processing devices 1
b is input to the common terminal c of the switching circuit 12b and the receiving unit 13b via the other connection terminal 11b.

In each of the switching circuits 12a and 12b, in a normal state, the common terminal c is connected to the normally closed terminal b. Then, the switching signals 14a, 14b from the receivers 13a, 13b.
The common terminal c is connected to the normally open terminal a only during the period when is input.

The receivers 13a and 13b are connected to the lines 2a and 2 respectively.
The signal state of b is monitored, and when the switching commands 15a and 15b are input from the information processing devices 1 via the lines 2a and 2b, the switching control signals 14a and 14b are transmitted to the switching circuits 12 respectively.
a, 12b, the common terminal c is switched to the normally open terminal a side, and the switching command 15a. 15b is sent to the next calculation unit 16.

When the switching commands 15a and 15b are input to the computing unit 16, the receiving units 13a and 13b switch to the switching signal 14a,
14b is released and the connection state is connected to the original common terminal c to the normally closed terminal b. As a result, the lines 2a and 2b are connected to the respective input terminals 17a and 17b of the selection circuit 17.

In the selection circuit 17, the input terminals 17a. 17b is alternatively connected to the five terminals 19a to 19e to which the five systems 4a to 4e of the transmission line 5 are connected. That is, each of the input terminals 17a and 17b is always connected to one of the systems 4a to 4e. However, both input terminals 17a and 17b are not connected to the same terminals 19a to 19e.

The calculation unit 16 is composed of a kind of computer, and internally has a waiting time counter 20 and a system selection unit 21. The waiting time counter 20 is a time in a state in which the corresponding systems 4a to 4e are not connected to any of the lines 2a and 2b for each of the systems 4a to 4e of the transmission line 5. Waiting time TC
Time 1 to TC5.

Each of the waiting times TC1 to TC5 is activated when the activation signal 22 designating the system number is input from the system selecting section 21. Then, it is counted up in synchronization with a clock signal output from an oscillator (not shown). When the clear signal 23 designating the system number is input from the system selecting unit 21, the corresponding waiting time among the five waiting times TC1 to TC5 is cleared to [0].

Further, the system selection unit 21 grasps, through the selection circuit drive units 18a and 18b, which system 4a to 4e each of the lines 2a and 2b is currently connected to. Then, for example, when the switching command 15a is input from the line 2a, the system selecting unit 19 selects the systems 4a to 4e having the longest waiting time TC among the waiting times TC1 to TC5 of the waiting time counter 20. Then, the selected one system 4a to 4e is sent to the selection circuit drive unit 18a.

At the same time, the system selecting section 19 sends a start signal 22 designating the system numbers corresponding to the currently connected systems 3a to 4e to the waiting time counter 20 to measure the waiting time TC1 to TC5 of the corresponding system. To start. Further, the clear signal 23 designating the system number corresponding to the system selected previously is sent to the waiting time counter 20 to clear the waiting times TC1 to TC5 of the corresponding system to [0].

Similarly, when the switching command 15b is input from the line 2b, the system selecting unit 19 selects the systems 4a to 4e having the longest waiting time TC in the waiting time counter 20. Then, the selected one system 4a to 4e is sent to the selection circuit drive unit 18b. And the currently connected system 4
Start the timing of waiting times TC1 to TC5 of a to 4e,
Waiting time TC1 to TC5 of the systems 4a to 4e selected this time
Is cleared to [0].

As described above, the waiting times TC1 to TC5 of the systems 4a to 4e in the waiting time counter 20 are cleared to [0] in the connecting state.
Next line 2a. In the state of waiting for 2b to be connected, the waiting times TC1 to TC5 are counted up.

The selection circuit drive sections 18a and 18b switch and connect the input terminals 17a and 17b of the selection circuit 17 to the terminals 19a to 19e of the systems 4a to 4e sent from the system selection section 21, respectively.

Therefore, the lines 2a and 2b are switched and connected to the respective systems 4a to 4e whose connection destination systems are selected by the system selecting unit 21. The operation of the transmission system switching device thus configured will be described with reference to the time chart of FIG.

In FIG. 2, for example, at time t ₀ ,
It is assumed that the power of the transmission system switching device is turned on. In this state, the waiting times TC1 to TC5 of the waiting time counter 20 of the arithmetic unit 16 are [0]. Then, in the initial process of power-on, it is assumed that the input terminals 17a and 17b of the selection circuit 17 are connected to the first and second systems 4a and 4b via the contacts 19a and 19b, respectively.

Therefore, at time t ₀ , the arithmetic unit 1
When 6 starts, the waiting times TC1 and TC2 of the first and second systems 4a and 4b maintain the [0] state, but the waiting times TC3 to TC5 of the other systems 4c to 4e start timing.

After time t ₀ , the information processing device 1 connected to the line 2a starts collecting data from one sensor 8 via the first system 4a, and the information processing device 1 connected to the line 2b. Starts collecting data from one sensor 8 via the second system 4b.

The time T ₁ 1 th information processing apparatus at the time t ₁ after the lapse of 1 is data collection process is completed for one of the sensors 8 and sends a switching command 15a through a line 2a, the switching command 15a Is input to the calculation unit 16. Then, the lines 4b to 4e of the switching connection destinations are selected by the system selecting unit 21, but at the beginning of power-on, the waiting times TC3, TC4, TC of the systems 4c to 4e are selected.
Since 5 are equal to each other (= T ₁ ), in this case, the system 4c having a number close to the system 4a currently connected is selected.
Therefore, at time t ₁ , the line 2a is connected to the grid 4c.

Further, at the time t ₂ , when the first information processing apparatus 1 completes the data collection processing for one sensor 8, the waiting time TC1 of the systems 4a, 4d, 4e,
TC4 and TC5 are compared and the system 4d, which has a long waiting time,
4d having a number close to the currently connected system 4c of 4e
Select.

Next, at time t ₃ , when the first information processing apparatus 1 completes the data collection process for another sensor 8, the system 4e TC5 = T ₁ + T ₂ + T ₃ with the longest waiting time is selected. .

[0038] Further, at time t _4, the data collection process for the first information processing apparatus 1 still further sensor 8 is completed, the most high latency systems _{4a TC1 = T 2 + T 3} + T 4 is selected .

[0039] Similarly, at time t _5, the data collection process for the first information processing apparatus 1 still further sensor 8 is completed, the most high latency systems _{4c TC3 = T 3 + T 4} + T 5 is selected It

Further, at time t ₆ , when the first information processing apparatus 1 completes the data collection processing for the further sensor 8, the system 4d TC4 = T ₄ + T ₅ + T ₆ having the longest waiting time is selected. .

Then, at time t ₇ , when the second information processing apparatus 1 completes the data collection processing for one sensor 8, the system 4e TC5 = T ₅ + T ₆ + T ₇ with the longest waiting time is selected.

In this way, the lines 4a to 4e having the longest waiting time at the time when the switching commands 15a and 15b are respectively output from the first and second information processing devices 1 are given priority to the lines 2a. 2b is switched and connected.

Incidentally, at time t ₁₀ the time chart of FIG. 2, if the line 2a, simultaneously switching command 15a from the information processing apparatus 1 of 2b, 15b is output, is set in advance when the high-priority The connection switching of the line 2a is performed first. As a result, as shown in FIG.
Then, the line 2b is switched and connected to the system 4e.

Therefore, it is possible to prevent an extremely long waiting time for only the specific systems 4a to 4e.
As a result, the communication load of each of the systems 4a to 4e forming the transmission line 5 can be made uniform.

Therefore, the communication efficiency of the communication system as a whole in which the transmission system switching device is incorporated can be improved. Further, since the selection processing of the switching connection destination systems 4a to 4e of the lines 2a and 2b is performed not on the information processing device 1 side but on the transmission system switching device side, the processing load on each information processing device 1 is reduced. Can be reduced.

Next, another method of using the transmission system switching device of this embodiment will be described. That is, each information processing device 1 is managed by the host computer, and one line 2a
Is set as the [control system], the other line 2b is set as the [data communication system], and the line 2a set as the [control system] is occupied for a certain period. Then, each data may be collected from each sensor 8 only by using the line 2b set as [data communication system].

In such a case, the control signal 24 is transmitted from the line 2a and the line 2a is transmitted to the specific system 4
Fix to d. In FIG. 3, the control signal 24 from the line 2a rises at time t _{11 and} the control signal 2 at time t ₁₇ rises.
4 is a time chart showing a connection state of the lines 4a to 4e with respect to the lines 2a and 2b when the number 4 is released.

As shown in the figure, the line 2a designated as [control system] maintains the connection state with the system 4d from time t ₁₁ to time t ₁₇ . Then, the line 2b designated as "data communication system" has the same structure as the time chart of FIG.
Each time the switching command 15b is input from the second information processing device 1, the system corresponding to the longest waiting time among the waiting times TC1, TC2, TC3, TC of the remaining systems 4a, 4b, 4c, 4e is selected. Switch and connect sequentially.

For example, at time t ₁₂ , when the information processing device 1 of the line 2b set as [data communication system] completes the data collection process for one sensor 8, the system 4a, which has the longest waiting time at that time, of _{4c TC1 = T 11 + T 12} TC3 = T 11 + T 12. The closer system 4a is selected.

Similarly, at the time t ₁₃ , when the second information processing apparatus 1 completes the data collection processing for this sensor 8, the system 4 with the longest waiting time at that time is obtained.
c TC3 = T ₁₁ + T ₁₂ + T ₁₃ is selected.

Then, at time t ₁₇ , when the designated control signal 24 for designating the [control system] is released, the information processing apparatus 1 on the line 2a sends the switching command 15a. As a result, the most high latency systems _{4c TC3 = T 15 + T 16} + T 17 at the time is selected, the line 2 has returned to its original state in this line 4c
a is connected.

From this point onward, as in the time chart of FIG. 2, the information processing device 1 on both lines 2a and 2b causes the switching command 1 to be issued.
Each time 5a, 15b is sent out, the connected systems 4a-4e are switched in order according to the above-mentioned switching algorithm.

As described above, even if a specific line is fixed to a specific system, other lines are sequentially switched and connected to a system having a long waiting time, so that a load is concentrated particularly on a specific system. There is nothing to do.

The present invention is not limited to the above embodiment. In the apparatus of the embodiment, the number of lines M is set to 2 and the number of lines N of the transmission line 5 is set to simplify the description.
Was set to 5, but it goes without saying that any combination satisfying the condition of N> M (N, M = a positive integer) may be used.

[0055]

As described above, the transmission system switching device of the present invention is provided with a waiting time counter for counting the time when each system constituting the transmission line is not connected to the line. Then, when the line is switched and connected to the next system, the system of the switching connection destination is allocated to the system having the longest waiting time. Therefore, it is possible to equalize the communication load of each system forming the transmission path, and it is possible to efficiently perform communication via each system of the transmission path.

[Brief description of drawings]

FIG. 1 is a block diagram showing a schematic configuration of a transmission line switching device according to an embodiment of the present invention.

FIG. 2 is a time chart showing the operation of the apparatus of the embodiment.

FIG. 3 is a time chart showing the operation of the apparatus of the same embodiment.

FIG. 4 is a block diagram showing a communication system incorporating a conventional transmission system switching device.

[Explanation of symbols]

1 ... Information processing device, 2a, 2b ... Line, 4a-4e ... System, 5 ... Transmission path, 12a, 12b ... Switching circuit, 13a.
13b ... Reception unit, 15a, 15b ... Switching command, 16 ... Calculation unit, 17 ... Selection circuit, 18a, 18b ... Selection circuit drive unit, 20 ... Wait time counter, 21 ... System selection unit.

Claims (1)

[Claims] 1. M lines among N lines in a transmission line having M lines, each of which is connected to the information processing unit and has N lines larger than the number of M lines, In a transmission system switching device that is always connected to each of the information processing units and responds to each switching command input from each of the information processing units to sequentially switch the connection destination system of each line to an empty system that is not connected. A wait time counter for counting the time in a state where its own system is not connected to any of the M lines, for each of the N lines forming the transmission line; A transmission system switching device comprising: a switching control unit that responds to a switching command and switches a corresponding line to an empty system that has the longest waiting time counted by the waiting time counter.