JPH1117709A - Transmission system for local area network - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable the early detection of SS-LAN abnormality, the specification of the fault occurrence and the notification of a spot where the fault occurs. SOLUTION: Concerning a system with which a point-of-sale information managing device (POS) 1e (master station) and plural pieces of equipment 1f-1i (slave stations) communicate through a polling/selecting system, a monitoring device 1a monitors whether a polling/selecting sequence is sent from the POS 1e within fixed time or not and when it is not sent within the fixed time, abnormality at an SS-LAN 1d is diagnosed. Then, the monitoring device 1a issues a command through a transmission line 1c to line disconnectors 1bf-1bi and when the SS-LAN 1d is not recovered normal even after the equipment 1f-1i is disconnected from the SS-LAN 1d, the POS 1e is regarded as a fault factor. When the SS-LAN is recovered normal, on the other hand, a command is issued to the line disconnectors 1bf-1bi to successively individually connect every equipment 1f-1i to the SS-LAN 1d and when any abnormality occurs, any one of equipment 1f-1i at that time is regarded as a fault factor. Then, that equipment is disconnected from the SS-LAN 1d, the SS-LAN is recovered normal and that fault equipment is notified to the outside on the other hand.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transmission system in a local area network in which a master station and a plurality of slave stations connected to the master station via a local area network communicate in a polling / selecting manner. About.

[0002]

2. Description of the Related Art A conventional transmission system using a local area network will be described with reference to FIG. In FIG. 12, a POS (point-of-sale information management device) is a master station in this local area network, and a weighing machine, an oil level gauge, a car washer and a change machine, which are equipment for a gas station, are slave stations in the local area network. This local area network adopts RS-485 as an interface standard, has a two-wire circuit configuration and a half-duplex communication system, and has a POS serving as a master station and equipment for each gas station serving as a slave station. They are connected by multi-drop. Then, communication is performed from the POS serving as the master station to each device for each gas station serving as the slave station in a polling / selecting manner. Here, the polling / selecting method is one of the communication procedures when communicating between one master station and a plurality of slave stations. When data is transmitted from the master station to the slave stations, the polling / selecting method is specified by the master station. Sends a transmission control character string (selecting sequence) to the local area network requesting the slave station to receive data, and if the slave station specified in the selecting sequence can receive, a response indicating that it can be received. While sending a message to the master station and receiving data from the master station,
If the data cannot be received, a response message indicating that the data cannot be received is transmitted.

When data is transmitted from a slave station to a master station, a transmission control character string (polling sequence) inviting the master station to transmit data to a specific slave station is sent to the local area network, and the polling sequence is transmitted. The designated slave station is a communication system in which, if there is data to be transmitted to the master station, the data is transmitted, and if not, a response message indicating that there is no data to be transmitted is transmitted.

That is, in the communication by the polling / selecting method, the master station has a communication control right, and the master station transmits a polling sequence to a plurality of slave stations at regular intervals in order, and the slave station transmits data. Need to receive.

[0005]

In the conventional transmission system described above, when a failure that affects the entire local area network occurs in any one of the equipment for a gas station as a slave station, the influence is applied to the gas station having the failure cause. Not only communication failure between equipment and POS, but also affects the entire local area network, communication failure between other normal gas station equipment and POS, and virtually all It's the same as gas station equipment that has failed.

Further, in order to find out the fault, it is necessary to manually check whether or not the local area network is normal by using a special device such as an online scope or the like. Even if an abnormality in the local area network is detected, in order to specify which gas station equipment is the cause of the actual failure, the power of each gas station equipment must be turned off or one gas station equipment must be turned off. Must be disconnected from the local area network and trying to recover the local area network.

Therefore, a first problem to be solved by the present invention is that when a failure occurs in a slave station such as a gas station equipment, the effect is not limited to the failure of the slave station but affects the entire local area network. As a result, PO
Communication between the master station such as S and other normal slave stations connected via the local area network cannot be performed, so that apparently all slave stations have failed, and the location of the fault is identified early. It is an object of the present invention to monitor the state of the local area network when it is difficult to detect an abnormality in the local area network at an early stage.

[0008] A second problem to be solved by the present invention is as follows.
Even if an abnormal state of the local area network can be detected early as described above, the local area network does not always recover normally, and not all slaves connected to the local area network are still normally controlled. The object of the present invention is to recover each local station by disconnecting each slave station one by one from the local area network and to specify which slave station has failed.

A third problem to be solved by the present invention is as follows.
Even if the system can be recovered by detecting the local area network abnormality early and disconnecting the faulty slave station from the local area network as described above, it is not apparent why the faulty slave station does not operate normally. The purpose of the present invention is to make it possible to notify the faulty slave station to the outside by display, voice, printing or the like.

[0010]

According to a first aspect of the present invention, a master station communicates with a plurality of slave stations connected to the master station via a local area network in a polling / selecting manner. In a transmission system in a local area network, it is monitored whether a polling sequence and / or a selecting sequence is transmitted from the master station within a predetermined time, and whether or not the sequence is transmitted within a predetermined time is determined based on whether the sequence is transmitted within a predetermined time. Thus, the above-described problem is solved by judging whether the error is normal or abnormal, thereby enabling the abnormality in the local area network to be accurately and promptly detected.

According to a second aspect of the present invention, in the case of the abnormality determination, the slave station is disconnected from the local area network to diagnose whether or not the local area network recovers normally. When not recovering normally, the master station considers the cause of the failure, and when it recovers normally, the master station considers that the cause is not the cause of the failure, and each of the disconnected slave stations is individually connected to the local area network. It is connected and diagnoses whether or not the local area network becomes abnormal.If no abnormality is detected, the slave station is determined to be normal. The local station is disconnected from the local area network and the local area network is restored normally. To separate the slave station is faulty as cause abnormalities throughout Area Network from a local area network, solves the problems described above and enables operation in the system configuration of other normal slave station.

According to a third aspect of the present invention, a slave station determined to be the cause of a failure is notified to the outside so as to be distinguishable from other slave stations. The above-mentioned problem is solved by making the notification possible.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a transmission system in a local area network according to an embodiment of the present invention will be described in detail.

FIG. 1 shows a configuration of a transmission system according to the present embodiment. Although the present embodiment is applied to a gas station as a local area, the applied local area is not limited to the gas station.

Referring to FIG. 1, in the transmission system of the present embodiment, POS (point of sale information management device) 1e serves as a master station in local area network 1d.
Gas station 1f, oil level meter 1g, car wash machine 1
h and the change machine 1i are slave stations in the local area network 1d. The local area network 1d has an interface standard of RS-485, a two-wire circuit configuration, a half-duplex communication system, and a POS 1e as a main station.
Each of the service station equipments 1f to 1i, which are slave stations, is connected by multi-drop. Then, the POS 1e, which is the master station, communicates with the respective stations 1f-1i for the gas stations, which are slave stations, by the polling / selecting method described above. Such a local area network 1d is commonly called SS-LAN at a gas station. In the following description, this local area network 1d is referred to as SS-L
AN1d. A POS 1e as a main station is connected to the SS-LAN 1d, and a weighing machine 1f, an oil level meter 1g, a car washer 1h, and a change machine 1 are respectively connected via line disconnecting devices 1bf to 1bi.
i are individually connected to each other. Here, the weighing machine 1f is for metering and supplying fuel oil such as gasoline, light oil, kerosene, etc., the oil level meter 1g is for measuring the residual oil amount in the underground tank of the gas station, and the car washer 1h is for The change machine 1i is used for depositing a sales amount and dispensing change in a transaction with a visitor to a gas station.

The SS-LAN 1d further includes an SS-LAN status monitor 1a for monitoring the status of the SS-LAN.
The SS-LAN status monitoring device 1a and each of the line disconnecting devices 1bf to 1bi (collectively referred to as 1b) are further connected via transmission lines 1cf to 1ci (collectively referred to as 1c). It is connected. In this embodiment, each of the SS-LAN status monitoring device 1a and each of the line disconnecting devices 1b is a wired transmission line 1
c, but may be connected wirelessly. (1) to (4) in the figure are transmission line numbers individually assigned to each of the plurality of transmission lines 1c. Such an SS-LAN status monitoring device 1a is SS-L
The state of the AN 1e is monitored, and based on the monitoring result, a command is individually issued to each of the line disconnecting devices 1b to disconnect or connect each of the gas station equipments 1f to 1i from the SS-LAN 1e. I have.

A circuit block configuration of the SS-LAN status monitoring device 1a will be described below with reference to FIG.
U2a is realized by a microcomputer or the like,
The SS-LAN status monitoring device 1a is entirely controlled.
The input device 2b performs input control of a keyboard or the like, and is used for input operation of setting data [5a] described later with reference to FIG. The ROM 2c stores a predetermined control program, and the RAM 2d is used as a storage area for setting data [5a] or a work area. The communication control device 2e is connected to the SS-LAN 1d,
-Read data on LAN1d. The display device 2f is C
It is realized by an RT, an LCD (liquid crystal display) or the like, and displays a message indicating that there is a faulty device. L
Each of the ED lamps 2j is individually paired with each of the transmission lines 1c, and indicates a faulty device by lighting the lamp. The printing device 2g is realized by a printer or the like, and prints a message indicating that there is a faulty device. The voice output device 2h outputs a voice message or the like indicating that a faulty device has been detected from a speaker. The communication control device 2i is connected one-to-one with each of the plurality of line disconnecting devices 1b via each of the plurality of transmission lines 1c. The clock / timer 2k performs a calendar function and time measurement.

Referring to FIG. 3, the format of the polling / selecting sequence will be described. The unit address (hereinafter referred to as UA) [3b] includes the polling / selecting distinction [3b-1] and the device type [3].
b-2]. The polling / selecting distinction [3b-1] indicates whether this message is a polling sequence or a selecting sequence. The equipment type [3b-2] is used to indicate to which gas station equipment the polling sequence / selecting sequence is. Specifically, the weighing machine is used as “1”, the oil level gauge is used as “2”, the car washer is used as “3”, and the change machine is used as “4”.

Station address (hereinafter referred to as SA)
[3a] is used as an address for further identifying an individual among the gas station equipments roughly classified by the equipment type [3b-2]. For example, when three weighing machines 1f are connected, the first weighing machine is used as [SA1], the second weighing machine is used as [SA2], and the third weighing machine is used as [SA3]. [ENQ3c] is a general transmission control character used to request a response from a station with which a line connection has been established in data transmission. SS from POS1e
Each refueling station device reads the polling sequence / selecting sequence sent to the LAN 1d, and [U
A3b] and [SA3a], it is determined whether it is a request to the own device or a request to another device. In the case of a request to the own device, whether the request is a data transmission request or a data transmission Determine whether the request is a reception request.

A communication sequence in the SS-LAN 1d will be described with reference to FIG. In FIG. 4, [4a]
Is an example in which the POS 1e transmits a polling sequence to the weighing machine 1f, and transmits a response indicating that there is no data to be transmitted from the weighing machine 1f. [4b] is POS
The polling sequence is sent from 1e to the oil level meter 1g,
In the oil level meter 1g, there is data to be transmitted, so that the data is transmitted. [4c] is POS1e
In this example, a polling sequence is transmitted to the car wash machine 1h from the car wash machine 1h, and a response indicating that there is no data to be transmitted or not is transmitted from the car wash machine 1h. [4d] transmits a polling sequence from the POS 1e to the change machine 1i, and sends the polling sequence to the change machine 1i.
This is an example in which a response to the effect that there is no data to be transmitted is transmitted.

[4e] indicates that the POS 1e is
f to the weighing machine 1f
In this example, a reception request is sent from the weighing machine 1f, a response to the effect that reception is possible is transmitted from the weighing machine 1f, and data is transmitted from the POS 1e. [4f] is an example in which the POS 1e transmits a selecting sequence to the weighing machine 1f, makes a reception request to the weighing machine 1f, and transmits a response indicating that reception is not possible from the weighing machine 1f.

In the POS 1e, when it becomes necessary to transmit data to a specific device, [4e], [4e]
f), a selecting sequence is transmitted, a response indicating whether or not reception is possible is received from the partner device, and data is transmitted when the partner device is in a receivable state. However, even when there is no need for data transmission, [4a], [4b], [4c],
Communication is performed as shown in [4d].

Referring to FIG. 5, the setting data [5a] stored in the RAM 2d of the SS-LAN status monitoring apparatus 1a will be described. The transmission line number [5a-1] is set in each of the plurality of transmission lines 1c. One transmission line is negotiated uniquely. The transmission line number of the transmission line 1cf is “1”, the transmission line number of the transmission line 1cg is “2”, the transmission line number of the transmission line 1ch is “3”, and the transmission line number of the transmission line 1ci is “1”. The number is “4”. The display / audio output data [5a-2] at the time of abnormality detection is the transmission line number [5a].
-1], which is alarm output data when an abnormality is detected.

Referring to FIG. 6, an image displayed on the display device 2f when an abnormality is detected by the SS-LAN state monitoring device 1a will be described. [6a] is the date and time when the abnormality is detected. 6b] is an alarm message. With reference to FIG. 7, an image printed on the printing device 2g when the SS-LAN status monitoring device 1a detects an abnormality will be described.
It is time, and [7b] is an alarm message.

Next, referring to FIGS. 8 to 11, SS-LA
The processing flow of faulty device determination and system recovery performed by the CPU 2a of the N-state monitoring device 1a will be described. Steps 1 to 19 in FIGS. 8 to 10 are main processes. Sub-steps 1 to 5 in FIG. 11 are subroutines called from the main processing. The main processing checks whether the SS-LAN 1d is normal or abnormal, and returns a result of the determination. The processes of steps 1 to 19 and sub-step 1 are written in the ROM 2c.

(A) Abnormality determination First, in step 1, the SS-LAN check subroutine of FIG. 11 is called, and in step 2, the SS-LAN check subroutine is called.
SS-LAN from check result of check subroutine
It is determined whether 1d is normal or abnormal.

The SS-LAN check subroutine will be described in detail. In sub-step 1, a timer of a clock / timer 2k is started to measure a predetermined time. In sub-step 2, SS-LAN1 is transmitted from communication control device 2e.
Read the data sent to d. Sub-step 3
Then, the data read in sub-step 2 conforms to the polling / selecting format shown in FIG. 3, and the polling / selecting distinction [3b-1]
Check if is a value indicating polling.
If this check is true, the information that the SS-LAN 1d is normal is returned to the main process, and if false, the process proceeds to sub-step 4.

In sub-step 4, the data read in sub-step 2 conforms to the polling / selecting format shown in FIG. 3, and the polling / selection distinction [3b-1] is a value indicating the selecting. Check if it is. If this check is true, SS-LANld returns information indicating that it is normal to the main processing, and if false, proceeds to sub-step 5. Then, in sub-step 5, it is checked whether the timer started in sub-step 1 has reached a predetermined time and timed out. If not, return to step 2;
LANld returns the information of the abnormality to the main process.

By the processing of the above substeps 1 to 5, it is checked whether or not a polling sequence or a selecting sequence has been sent to the SS-LAN 1d within a predetermined time, and an abnormality of the SS-LAN 1d is detected.

The above-described abnormality determination in (a) is an explanation of the processing flow according to claim 1 in the claims.

(B) Processing after abnormality determination When an abnormality of the SS-LAN 1d is detected in step 2, the process proceeds to step 3. In step 3, "0" is substituted for a variable n secured in the work area of the RAM 2d. This variable n is data used as an index of the setting data 5a in FIG. Next, at step 4, the variable n + 1 is substituted for the variable n. After this substitution, in step 5, each line disconnecting device is connected via each transmission line 1c indicated by the n-th (indicated by the variable n) transmission line number [5a-1] in the setting data [5a-1]. 1b is instructed to disconnect. For example, when the variable n is “1”, “1” is obtained for the transmission line number 5a-1. From the value, the disconnection is instructed to the line disconnecting device 1bf via the first transmission line 1cf, and as a result, the weighing machine 1f is disconnected from the SS-LAN 1d. In Step 6, it is compared whether the variable n is smaller than "4". If the variable n is smaller than "4", the process returns to Step 4. If the variable n is "4" or more, the process proceeds to Step 7. In this example, since the number of data items included in the setting data [5a] is “4”, the variable n is compared with “4”. In other words, the variable n is changed from 1 → 2 → 3 → 4, and the processing of steps 4 and 5 is performed for all the cases in the setting data 5a.
Instruct all the line disconnecting devices 1b to disconnect, and disconnect all the gas station equipment from SS-LANEld.

In step 7, an SS-LAN check subroutine is called. In step 8, it is determined from the subroutine check result in step 7 whether SS-LANld is normal or abnormal. Steps 3 to 6 above
Since all the equipment for the gas station has been disconnected from the SS-LAN 1d in the processing up to the above, if the cause of the failure is on the equipment for the water supply station, the SS-LAN 1d recovers and becomes normal at step 8. If abnormal, the POS 1e can be determined to be the cause of the failure. If the SS-LAN 1d is recovered in step 8, the process proceeds to step 9 in FIG. In step 9, "0" is substituted for a variable n. After this substitution, in Step 10, the variable n + 1 is substituted for the variable n.

Next, in step 11, the line disconnecting device 1b is connected via the transmission line 1c indicated by the n-th (indicated by the variable n) transmission line number [5a-1] in the setting data [5a-1]. To connect. For example, when the variable n is “1”, “1” is obtained for the transmission line number [5a-1]. From this value, the connection is instructed to the line disconnecting device 1bf via the first transmission line 1cf, and as a result, the weighing machine 1f is connected to the SS-LAN 1d. And step 12
Then, the SS-LAN check subroutine is called.
After this call, in step 13, it is determined from the subroutine check result in step 12 whether the SS-LAN 1d is normal or abnormal. If the SS-LAN 1d recovers to the normal state at this point, the equipment for the gas station connected in the immediately preceding step 11 can be determined to be normal, and the process proceeds to step 19 in FIG. If it does not recover to the normal state, the connected device can be determined to be the cause of the failure in the immediately preceding step 11, and in that case, the process proceeds to step 14 in FIG. In step 14, in order to disconnect the device connected in the immediately preceding step 11 from the SS-LAN 1d again, the setting data [5
a-1] to the line disconnecting device 1b via the transmission line 1c indicated by the n-th (indicated by the variable n) transmission line number [5a-1]. Steps 15-18 are
This is a process of alarming an abnormal gas station equipment.
The processing flow according to claim 3 of the claims will be described. Thus, after steps 15 and 18, step 19
Then, it is compared whether the variable n is smaller than “4”. If the variable n is smaller than “4”, the process returns to step 4;

In this example, since the number of data items included in the setting data [5a] is “4”, the variable n is compared with “4”. That is, the variable n is changed from 1 → 2 → 3 → 4, and steps 10 to 1 are performed for all the cases in the setting data 5a.
9 is performed, the abnormal service station equipment causing the failure is disconnected from the SS-LAN 1d, and only the normal service station equipment is connected. As described above, by disconnecting the abnormal device causing the failure from the SS-LAN 1d in the steps 3 to 19 described above, the SS-LAN 1d is restored to a normal state. The system can be operated.

In the case of the abnormality determination, the gas station equipment 1f to 1i is disconnected from the SS-LAN 1e one by one or sequentially by a predetermined number to diagnose whether or not the SS-LAN 1e recovers normally. Then, the equipment for the gas station that was disconnected at the time of the normal recovery is regarded as the cause of the failure, and the equipment station for the gas station that is the cause of the failure is disconnected from the SS-LAN 1e to recover the SS-LAN 1e normally. I do not care.

The above-mentioned processing after the abnormality determination in (b) is an explanation of the processing flow according to claim 2 in the above claims.

(C) Identification of a device causing a failure In step 13 in the above (b), when it is determined that the device is a device causing a failure, in step 15, the n-th data in the setting data [5a-1] (variable n is used). LED with the same number as the value indicated by the transmission line number [5a-1]
The lamp 2j is turned on. Since the LED lamps 2j correspond to the individual transmission lines 1c on a one-to-one basis, it is easily apparent from the appearance which device is causing the failure. In step 16, the date / time read from the clock / timer 2k and the display / print / audio output data [5a-1] at the time of detecting the nth (indicated by the variable n) abnormality in the setting data [5a-1] -2] is output to the display device 2f as shown in FIG. In step 17, the date / time read from the clock / timer 2k and the display / print / voice output data [5a-1] at the time of detecting the n-th (indicated by the variable n) abnormality in the setting data [5a-1] -2] to the printing device 2g as shown in FIG.
Output as shown. In step 18, the display / print / audio output data [5a-2] at the time of detecting the n-th (indicated by the variable n) abnormality in the setting data [5a-1]
Is output to the audio output device 2h.

By the steps 15 to 18 described above, the equipment for the gas station determined to be the cause of the trouble can be easily identified in appearance.

The identification of the device causing the failure in the above (c) is an explanation of the processing flow according to the third aspect of the present invention.

A transceiver as shown in Japanese Patent Application Laid-Open No. 7-95217, that is, a transceiver is provided with a terminal, and the terminal is turned on / off by an instruction from the host, to connect / disconnect a bus after the transceiver. In the method of determining whether the transmission path is normal or abnormal, the transmission path itself has no abnormality and cannot be applied to a failure in which the transmission path becomes abnormal due to the cause of the terminal device. This can be applied to a failure in which the transmission path becomes abnormal due to a cause on the terminal device side.

[0041]

As described above, according to the present invention, the following effects can be obtained.

According to the first aspect of the present invention, if a failure occurs in the communication system of the gas station equipment and an abnormality occurs in the entire SS-LAN due to the failure, the abnormality is detected early without any manual operation. be able to.

According to the second aspect of the present invention, the faulty device can be disconnected from the SS-LAN without manual intervention, and the system can be restored with a configuration including only normal devices.

According to the third aspect of the present invention, a faulty device can be easily identified.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a transmission system according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a basic configuration of an SS-LAN status monitoring device.

FIG. 3 is a format diagram of a polling selecting sequence.

FIG. 4 is a diagram showing an example of a communication sequence.

FIG. 5 is a diagram showing an example of setting data.

FIG. 6 is a diagram showing an example of an alarm display image when an abnormality is detected.

FIG. 7 is a diagram showing an example of an alarm print image when an abnormality is detected.

FIG. 8 is a diagram showing a main processing flow for determining a faulty device and restoring the system in the SS-LAN status monitoring device.

FIG. 9 is a flowchart of a main process of determining a faulty device and restoring the system in the SS-LAN status monitoring device.

FIG. 10 is a main processing flow chart for determining a faulty device and restoring the system in the SS-LAN status monitoring device.

FIG. 11 is a processing flowchart of a subroutine for determining a faulty device and restoring the system in the SS-LAN status monitoring device.

FIG. 12 is a diagram showing an example of a system configuration showing a conventional technique.

[Explanation of symbols]

 la SS-LAN condition monitoring device 1bf-1bi Line disconnecting device 1cf-1ci Transmission line le POS ld SS-LAN lf Measuring machine lg Oil level gauge lh Car wash machine 1i Change machine

Claims (3)

[Claims] 1. A transmission system in a local area network in which a master station and a plurality of slave stations respectively connected to the master station via a local area network communicate in a polling / selecting system. Monitoring whether or not the polling sequence and / or the selecting sequence are transmitted within a predetermined time; and determining whether the local area network is normal or abnormal based on whether or not the sequence is transmitted within a predetermined time. Transmission system in a local area network. 2. In the case of the abnormality determination, the slave station is disconnected from the local area network to diagnose whether or not the local area network recovers normally. If the local area network does not recover normally, The master station considers the cause of the failure, and when normal recovery is performed, the master station considers the cause of the failure not to be the cause of the failure and individually connects the disconnected slave stations to the local area network. Diagnose whether or not the local area network becomes abnormal.If it does not, the slave station is determined to be normal. The local area according to claim 1, wherein the local area network is normally restored by disconnecting from the network. Transmission system in Ttowaku. 3. The transmission system in a local area network according to claim 2, wherein the slave station determined as the cause of the failure is notified to the outside so as to be distinguishable from other slave stations.