JP3355961B2 - Transmission system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transmission system for communicating between a control station and a plurality of slave stations.

[0002]

2. Description of the Related Art When data is exchanged between a control station and a plurality of slave stations, a bus-type transmission system for transmitting serial data using a bus-type transmission path is often used. FIG. 8 is a connection diagram schematically showing a conventional transmission system in which a control station, a first slave station, a second slave station, a third slave station, and a fourth slave station are connected by a bus-type transmission path. In the figure, reference numeral 801 denotes a control station having a function of controlling up to five slave stations. The first slave station, the second slave station, and the third slave station are single station number occupying slave stations occupying only one station number (having one slave station), and the fourth slave station is occupying 2 station numbers.
This is a slave station occupying a plurality of station numbers (having two slave stations) occupying one station number. 512 is a control circuit, 508 is a parallel / serial conversion circuit, 509 is a serial / parallel conversion circuit, 601 is a station number setting switch, 602 is a general-purpose input / output circuit unit for connecting to a CPU or the like, 604 is a slave station to the control station 801. 605, a signal line for transmitting serial data to
Is a signal line for transmitting serial data from the control station 801 to the slave station, and 701 is a station number addition value setting circuit. The first
The station number setting switches 601 of the slave station, the second slave station, the third slave station, and the fourth slave station are set to 1, 2, 3, and 4, respectively. When "1" is set in the addition value setting circuit 701 in the fourth slave station, the station number of the first slave station is 1, the station number of the second slave station is 2, the station number of the third slave station is 3, and the fourth slave station is the station number. 4 and station number 5 are occupied.

FIG. 6 is a block diagram showing a single station number occupied slave station. In the figure, reference numeral 603 denotes a modulation / demodulation circuit;
Reference numerals 1, 504, 505, 510, and 511 denote station number data input terminals, added value setting terminals, I / O buffers and general-purpose input / output terminals of the control circuit 512, serial data transmission external output terminals, and reception external inputs, respectively. Terminal.

FIG. 5 is a block diagram showing details of the control circuit 512. In the figure, reference numeral 502 denotes a station number holding circuit,
503 is a station number adding circuit, 506 is a transmission data buffer and transmission control circuit unit, and 507 is a reception data buffer and reception control circuit unit.

FIG. 7 is a block diagram showing the internal arrangement of a slave station occupying a plurality of station numbers. This multiple occupancy slave station is provided with two control circuits 512 shown in FIG. Station number addition value setting circuit 7
01 holds a value to be added to the station number set by the station number setting switch 601. This multi-station number occupied slave station can exchange twice the amount of data (data for two slave stations) as compared with the single station number occupied slave station shown in FIG.
The slave station shown in FIG. 7 is used when, for example, the data from the data amount exceeding the data amount for one slave station to the data amount for two slave stations becomes meaningful data for one group.

FIG. 9 is an explanatory diagram showing a configuration of a transmission frame transmitted from the control station 801 to a slave station. In the figure, 9
01 is the area of the data transmission start flag, 902 is the area of the destination address (station number of the destination slave station), 903 is the area of the control code, 904 is the area of the slave station data, 905
Is an area for a transmission error control code, and 906 is an area for a data transmission end flag. The control station 801 sends data to the slave station using a transmission frame of such a format.
In the single station number occupied slave station shown in FIG. 6, the amount of data transmitted by one transmission with the control station is the amount of data transmitted by one transmission frame. It should be noted that the data to be put in the area 904 of one transmission frame is referred to as data for one slave station.

For example, when transmitting data only to the second slave station in FIG. 8, the control station 801 operates in the area 9 in FIG.
In the area 90, "02" which is the station number of the destination slave station is added to the area 90.
3, a transmission frame in which a code or the like indicating that the slave station 2 may receive data transmission from the control station 801 is transmitted. Each slave station determines that the transmission frame is addressed to its own station when the station number in the area 902 matches the own station number, and takes in the contents. That is, in this case, only the second slave fetches the contents of area 904 of the transmission frame.

FIG. 10 shows a transmission request from a control station (hereinafter referred to as a transmission request).
FIG. 8 is a diagram illustrating a transmission frame transmitted from a slave station to a control station as a response to the polling (shown as polling). In the figure, 1
001 is an area of the address of the control station 801 (“00” which is the station number of the destination control station), and 1002 is an area of data to be transmitted to the control station 801 (data for one slave station).
The slave station makes a polling response with a transmission frame of such a format.

Next, the operation of the system shown in FIG. 8 when the control station 801 exchanges data with the second slave station will be described. When transmitting to the second slave station, in the transmission frame shown in FIG. 9, the station number "02" which is the address of the slave station of the transmission destination is written in the area 902, and the slave station data is written and transmitted in the area 904. Upon receiving this, the second slave station refers to area 905,
If no transmission error is found, it is regarded as a normal reception and a transmission frame for the own station, and the slave station data is held inside.

[0010] Next, the second slave station responds as a response indicating normal reception to the area 100 of the transmission frame shown in FIG.
2 to the control station 8
Send to 01. In the case of polling, dummy data is written in the data received from the control station 801 (in the area 1002), and information indicating that only polling is performed is written in the area 903.

When the control station 801 transmits data to the fourth slave station, the fourth slave station is a slave station occupying a plurality of station numbers having a plurality of (two) slave stations. Both the transmission frame to the station and the transmission frame to the slave station 5 of the station number 5 are individually transmitted. On the fourth slave station side, the transmission frame for the slave station of station number 4 is the addition value setting terminal 50.
4 is received by the control circuit 512 that is grounded, and the transmission frame to the slave station of station number 5 is received by the control circuit 512 in which the signal from the station number addition value setting circuit 701 is input to the addition value setting terminal 504. The fourth slave station can receive data for two slave stations from the control station 801 in this way.

For example, the station number setting switch 6 of the fourth slave station
When 01 is set to "5", the two station numbers occupied by the fourth slave station are 5 and 6, respectively. Since the control station 801 can handle up to five station numbers, the control station 801 cannot perform data transmission and polling for the child station even if there is such a child station with the station number 6. Therefore, the control station 801 cannot recognize the slave station having the station number 6 even if it exists.

In the conventional system shown in FIG. 8, at the time of transmission from the control station 801 to the fourth slave station (transmission to a slave station with a station number of 4 and a slave station with a station number of 5), one of the slave stations If the data cannot be received normally due to an error, the fourth slave station is configured to keep the data received immediately before.

The station number of the slave station is determined directly on the basis of the setting of the station number setting switch 601 shown in FIG. The transmitted transmission frame to the own station is recognized as being for the other station, and normal reception cannot be performed. If the station number setting is changed after the power is turned on, the control station 801 cannot update the internal data in accordance with the change of the station number setting. Therefore, the station number cannot be changed after the power is turned on.

[0015]

In the conventional transmission system, there is a slave station having a slave station having a station number larger than the control station 801 can handle, or a slave station whose station number has changed due to a failure or erroneous operation of the station number setting switch 601. Control station 80
Since No. 1 could not be recognized, it was difficult to determine the cause of the malfunction. In the case of a slave station occupying a plurality of station numbers, if a slave station capable of normal reception and a slave station that cannot normally receive signals coexist in the slave station, the slave station receiving the normal reception is not disconnected. Cannot be replaced with a good product and maintenance is not easy.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has as its object to provide a transmission system capable of reporting to a control station when a station number exceeding a set range exists.

Further, when there is a slave station in which a transmission error or a circuit failure has occurred in a slave station occupying a plurality of station numbers, the control station is notified via a normal slave station, and all slave stations in the slave station occupying a plurality of station numbers are disconnected. The aim is to get the system.

It is another object of the present invention to provide a transmission system capable of transmitting a change in a station number setting value to a control station after power-on due to a failure of a station number setting switch or the like.

[0019]

A transmission system according to the present invention is a transmission system in which communication is performed between a control station occupying a plurality of station numbers having a plurality of slave stations therein and a control station.
The slave station occupying a plurality of station numbers is a means for judging whether an abnormal station number set as a station number exceeding the maximum station number that can be handled by the control station exists as a slave station within the own station, and a slave station within the own station. Signal transmission means for exchanging information between the
Based on the determination by the determining means that the abnormal station number exists, the abnormal station number reports an abnormality to the normal station number via the signal transmission means, and the slave station occupying a plurality of station numbers uses this station number within its own station. Is to notify the control station of the presence of the abnormal station number via the normal slave station.

In a transmission system in which communication is performed between a control station occupying a plurality of station numbers and a plurality of slave stations having a plurality of slave stations therein, the slave station occupying a plurality of station numbers is a signal for exchanging information between slave stations within the own station. It has a transmitting means, and when an abnormal receiving slave station that cannot be received normally occurs in the slave station occupying a plurality of station numbers, the abnormal receiving slave station reports an abnormality to the normal receiving slave station that can normally receive via the signal transmitting means. The slave station occupying a plurality of station numbers reports this abnormality to the control station via the normal receiving slave station in the own station so that all slave stations in the own station are disconnected from the operating system configuration.

In a transmission system in which communication is performed between a slave station and a control station, the slave station holds a switch for setting a station number and information from the switch for setting a station number, and the current station number of the slave station holds the information. Holding means determined based on the contents, detecting means for detecting a change in the station number designation by the station number setting switch based on a difference between the held contents of the holding means and information from the station number setting switch,
And transmitting means for transmitting information indicating the change to the control station when the detecting means detects the change in the designation of the station number.

The slave station has a station number change permission switch for switching the current station number of the slave station from a station number based on the contents held in the holding means to a station number based on information from a station number setting switch.

[0023]

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiment 1 FIG. FIG. 4 is a configuration diagram of an example transmission system according to the present invention. This transmission system is a transmission system for transmitting serial data, and has a control station, a first slave station, a second slave station, a third slave station, and a fourth slave station. The first slave station, the second slave station, and the third slave station are single station number occupied slave stations occupying only one station number, and the fourth slave station is a multiple station occupied slave station occupying two station numbers. 1st slave station,
The station numbers of the second and third slave stations are “1” and “1”, respectively.
2 "and" 3 ", and the fourth slave station has station numbers" 4 "and" 4 ".
FIG. 4 shows a case where there are three single-station-number occupied slave stations and one multiple-station-number occupied slave station. However, the number of stations that can be handled by the control station 801 is not limited to this. Any number within the range may be present.

FIG. 2 is a block diagram of the single station occupied slave station shown in FIG. In FIG. 2, reference numeral 202 denotes a single station number occupied slave station, 113 a control circuit, and 201 a station number change permission switch.

FIG. 1 is a block diagram showing details of the control circuit 113 of FIG. In the figure, 101 is a station number change switch terminal, 102 is a detecting means, for example, a set station number /
This is a transmission station number comparison circuit. 104 is a slave station internal communication control unit; 104a is a maximum station number holding means in which the maximum station number which can be handled by the control station 801 is stored or set in advance; 10b is a holding content of the maximum station number holding means and a holding content of the station number holding circuit 502. A determination unit, for example, a determination circuit that performs comparison and determines whether the station number is abnormal. 107 is a slave communication interface, 109 is a slave communication input terminal, 112
Is a slave communication output terminal.

FIG. 3 is a block diagram of a fourth slave station, which is a slave station occupying a plurality of station numbers occupying two station numbers, among slave stations used in the transmission system of FIG. In the figure, the fourth slave station 303 has two control circuits 113 and 30
1 is a communication output terminal 11 in the slave station of one control circuit 113
2 to the slave communication input terminal 1 of the other control circuit 113
A bus for transmitting a signal to the control circuit 09;
From the slave internal communication input terminal 112 to one of the control circuits 11
3 is a bus for transmitting a signal to the slave station communication output terminal 109. Note that one control circuit 113 and the other control circuit 1
13 is constituted by a bus 301 and a bus 302. In the fourth slave station 303,
When the station number setting switch 601 is set to “n” and the addition value setting circuit 701 is set to “1”, the two station numbers occupied by the fourth slave station 303 are respectively (n ) And (n + 1).

In the transmission system shown in FIG. 4, when the power is turned on, the first to fourth slave stations each transmit the station number set by the station number setting switch 601 to the control circuit 1.
13 and stored in the station number holding circuit 502, and thereafter, the station number (current station number) held in the station number holding circuit 502.
To perform data transmission. In this way, by not using the station number from the station number setting switch 601 as it is as the current station number, it is possible to prevent an abnormal change in the station number due to erroneous operation or malfunction of the station number setting switch during transmission.

If the setting station number / transmission station number comparison circuit 102 detects a mismatch between the station number from the station number setting switch 601 and the current station number during transmission due to a failure of the station number setting switch 601 or the like, the control is performed. At the time of data transmission or polling response from the station 801, the transmission frame shown in FIG. 10 in which this information is written in the area 903 is transmitted to the control station 801. The transmission means for transmitting the information indicating the mismatch to the control station 801 is implemented by a transmission data buffer and transmission control circuit 506 and a parallel / serial conversion circuit 508. To change the station number after turning on the power, the station number change permission switch 20
By turning on 1, the station number set in the station number holding circuit 502 is updated to the station number from the station number setting switch 601.

In the transmission system shown in FIG. 4, when the station number setting switch 601 of the fourth slave station is set to "5", the two station numbers occupied by the fourth slave station are 5
And 6. Since the station number that can be handled by the control station 801 is up to 5, the control station 801 cannot directly receive the information indicating the station number abnormality from the slave station having the station number 6 (the other control circuit 113) in the fourth slave station. A maximum station number that can be handled by the control station 801 is stored in advance in the fourth slave station, and the fourth slave station determines whether or not a slave station whose station number is set to a station number exceeding the maximum station number exists in its own station. Can be determined.

If one of the two slave stations of the fourth slave station has an abnormal station number, the abnormal slave station (the control circuit 11 having an abnormal station number setting) is connected via the bus 301.
From 3), an error code indicating an abnormal station number setting is sent to a slave station having a normal station number setting (control circuit 113 having a normal station number setting). When receiving the error code, the slave station having the normal station number setting transmits a transmission frame in which the error code is written in the area 903 in FIG. 10 to the control station 801. The control station 801 receives this transmission frame,
It recognizes that there is a slave station having a slave station whose station number setting is abnormal.

When one of the two slave stations corresponding to each of the two station numbers occupied by the fourth slave station detects its own communication abnormality such as poor reception, the bus 30
1 or information indicating a communication abnormality to the normal slave station via the bus 302. As a response to the polling of the normal slave station from the control station 801, the normal slave station writes information indicating that there is a slave station having a communication error in the area 903 of the transmission frame, and transmits the information to the control station 801. Upon receiving this transmission frame, the control station 801 disconnects both of the two slave stations in the fourth slave station from the system. With such a configuration, the operator in charge of the system maintenance in the event of an abnormality removes the entire fourth slave station,
The replacement work can be facilitated simply by replacing the slave station with a good one. Also, in the embodiment of the present invention, a case has been described in which a plurality of station numbers occupied slave stations occupy two station numbers. However, the present invention is not limited to this, and three or more station numbers may be occupied. Accordingly, processing such as handling a larger amount of data as a set of data becomes possible.

[0032]

As described above, according to the present invention, a slave station occupying a plurality of station numbers has an abnormal station number slave station set to a station number exceeding the maximum station number that can be handled by the control station as a slave station within the own station. The determination means determines whether or not there is, based on the determination of the determination means that an abnormal station number slave station is present, the abnormal station number slave station reports an abnormality to a slave station having a normal station number via signal transmission means, The slave station occupying a plurality of station numbers notifies the control station of the existence of a slave station having an abnormal station number through a slave station whose station number is normal in its own station. There is an effect that the prevention of errors and the like can be facilitated.

Further, when an abnormal receiving slave station that cannot be normally received occurs in the slave station occupying a plurality of station numbers, the abnormal receiving slave station reports an abnormality to the normal receiving slave station that can receive normally via signal transmission means. The slave station occupying a plurality of station numbers reports this abnormality to the control station via the normal receiving slave station in the own station so that all slave stations in the own station are disconnected from the operating system configuration. There is an effect that the unit can be replaced with a non-defective one and maintenance can be facilitated. In addition, since such an operation can be performed even when the control station does not have information on the slave stations in the slave station, an operation for setting such information can be omitted and the operation can be simplified.

The slave station holds the information from the station number setting switch and determines the current station number of the own station based on the held contents, based on the difference between the held contents of the holding means and the information from the station number setting switch. When the detecting means detects a change in the station number designation by the station number setting switch, the transmitting means sends information indicating this change to the control station,
Even if the station number setting changes due to a failure or erroneous operation of the slave station number setting switch, data communication can be performed normally. Further, there is an effect that occurrence of a malfunction at the next power-on can be prevented.

Further, the slave station has a station number change permission switch for switching the current station number of its own station from the station number based on the contents held in the holding means to the station number based on the information from the station number setting switch. Thus, there is an effect that the station number of the own station can be changed and a decrease in the reliability of the station number setting can be prevented.

[Brief description of the drawings]

FIG. 1 is a block diagram of a control circuit according to an embodiment of the present invention.

FIG. 2 is a block diagram of a single station number occupied slave station according to the embodiment of the present invention;

FIG. 3 is a block diagram of a multiple station number occupying slave station occupying two station numbers according to the embodiment of the present invention;

FIG. 4 is a configuration diagram of a transmission system according to an embodiment of the present invention.

FIG. 5 is a block diagram of a conventional control circuit.

FIG. 6 is a block diagram of a conventional single station number occupied slave station.

FIG. 7 is a block diagram of a conventional multiple station number occupying slave station occupying two station numbers.

FIG. 8 is a block diagram showing a conventional transmission system.

FIG. 9 is a diagram illustrating a configuration of information transmitted from a control station to a slave station.

FIG. 10 is a diagram showing a configuration of information transmitted from a slave station to a control station.

[Explanation of symbols]

 101 Station number setting change switch 102 Setting station number / transmission station number comparison circuit 104 Intra-station communication control circuit 107 In-station communication I / F 109 In-station communication input terminal 112 In-station communication output terminal 113 Control circuit 201 Station number change permission Switch 202 Single station number occupied slave station 301 Bus 302 Bus 303 Multiple station number occupied slave station 501 Station number data input terminal 502 Station number holding circuit 503 Station number addition circuit 504 Addition value setting terminal 505 I / O buffer and general-purpose input / output terminal 506 For transmission data Buffer and transmission control circuit 507 Receive data buffer and reception control circuit 508 Parallel / serial conversion circuit 509 Serial / parallel conversion circuit 510 Serial data external output pin 511 External reception input pin 512 Control circuit 601 Switch for station number setting H 602 General-purpose input / output circuit section 603 Modulation / demodulation circuit 604 Signal line 605 Signal line 701 Station number addition value setting circuit 801 Control station 901 Data transmission start flag 902 Destination address 903 Transmission data control code 904 Data section 905 Transmission error control code 906 Data Transmission end flag 1001 Control station address 1002 Transmission data to control station

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H04L 12/40-12/417 H04L 12/28 H04L 12/44-12/46

Claims (4)

(57) [Claims] In a transmission system in which communication is performed between a slave station occupying a plurality of station numbers having a plurality of slave stations therein and a control station, the slave station occupying a plurality of station numbers is a station number exceeding the maximum station number that the control station can handle. A determining means for determining whether or not the abnormal station number slave station set as a slave station in the own station, and a signal transmitting means for exchanging information between the slave stations in the own station, Based on the determination by the determination means that the abnormal station number slave station is present, the abnormal station number slave station reports an abnormality to the slave station having a normal station number via the signal transmission means, and the multiple station number occupied slave station. Is a transmission system for notifying the control station of the existence of the abnormal station number slave station via the slave station whose station number is normal in the own station. 2. A transmission system in which communication is performed between a control station occupying a plurality of station numbers and a plurality of slave stations occupying a plurality of slave stations therein, wherein the slave stations occupying the plurality of station numbers exchange information between the slave stations within the own station. Having a signal transmitting means for performing, when an abnormal receiving child station that cannot be normally received occurs in the plurality of station number occupied slave stations, this abnormal receiving child station transmits to the normal receiving child station that can receive normally via the signal transmitting means. An abnormality is reported, the slave station occupying the plurality of station numbers reports the abnormality to the control station via the normal receiving slave station in the own station, and all slave stations in the own station are disconnected from the operating system configuration. A transmission system characterized by the above. 3. A transmission in which communication is performed between a slave station and a control station.
In the transmission system, the slave station is a switch for setting a station number, holding means for holding information from the switch for setting the station number, and a current station number of the slave station being determined based on the held content, Detecting means for detecting a change in the station number designation by the station number setting switch based on a difference from information from the station number setting switch; and information indicating the change when the detecting means detects the change in the station number designation. A transmission means for transmitting to a control station. 4. The slave station according to claim 3, wherein the slave station has a station number change permission switch for switching the current station number of the slave station from a station number based on the held content of the holding means to a station number based on information from a station number setting switch. Transmission system.