JPS62143597A - Data transmission system - Google Patents

Abstract

PURPOSE:To decrease the terminal control processing burden of a host computer and to increase the control response speed by making a center equipment discriminate whether or not the prescribed change in the data received from a terminal exists. CONSTITUTION:A detecting designating command data 50 including a detecting designating code 53 is received from a host computer 1, and the center equipment 3, while communication is repeated at the division of a terminal, decides and checks the presence and the absence of the change given by a designating code 53 to the terminal input data transmitted from the terminal 4. When the corresponding change exists, the terminal input data are transmitted to the host computer 1. The host computer 1 transmits the control data (on and off command, etc.,) to be given to the partinent terminal to the center equipment 3, and the center equipment 3 transmits the control data to a pertinent terminal 4 in the next communication.

Description

[Detailed description of the invention] [Technical field to which the invention pertains]

This invention relates to a plurality of terminal devices (also referred to as terminals). The present invention relates to a data transmission system composed of a center device and a host computer, in which the host computer and the center device are provided with means for detecting changes in terminal data. Note that in the description of each figure below, the same reference numerals indicate the same or corresponding parts. Also, the logical rule gh, I, o11 is simply H,
It is written as L.

[Prior art and its problems]

The closest prior art to the present application is Japanese Patent Application No. 59-244254 "Data Transmission System J" filed by the present applicant. This type of technology and its problems will be explained below using Figures 5 to 9. 5 shows a system configuration diagram of this type of data transmission system.The center device 3 is connected to a large number of terminals 4 (4-L to 4-n) via a signal path 5. L, data transmission is performed between the center device 3 and the terminal 4 as shown by arrows a and b, or between the terminals as shown by arrow C2d.The configuration of the signal path with the terminals is shown in FIG. , are connected in a loop, but may also be connected in a multi-drop manner or branched out.The functions of the terminal include the connected digital or analog input fA (j Both are transmitted as serial data via the signal path 5.The terminal also outputs the data received via the Shingetsu path 5 to the outside of the system.
It has a function to output as J7. Furthermore, each terminal 4
Each device is assigned a unique address and has a built-in address switch for settings. In the case of transmission between terminals (hereinafter referred to as N:N transmission method), consecutive even and odd addresses are determined to transmit data to each other. That's because I decided to do this.L, just think of it as an example. When an address is designated, the input signal of the terminal with the odd number address is transmitted, and the terminal with the even number address receives and outputs this signal. Data transmission is then performed between the terminals in such a way that the input signal of the even-addressed terminal is transmitted, and the odd-addressed terminal receives it. On the other hand, transmission between the center device and the terminals (hereinafter referred to as 1;N transmission method) is also performed as follows. The center device is connected to the host computer 1 via a transmission path (R3232C cable or data bus) 2, and the host computer 1 sends terminal operation signals, etc. to the center device 3, and the center device 3 receives the signals from the host computer 1. :N transmission system to transmit output data to the terminal, L output from the terminal to the outside, 1:N transmission to receive terminal input data, and send the received terminal data to the host computer 1. do. In addition, since the center unit W3 receives all the signals on the signal path 5, it can also monitor data in the NUN transmission method.Although the data transmission itself is carried out between terminals, it is not possible to monitor the contents. Accordingly, it is possible to transmit designated terminal data to the host computer 1 from among the N:N transmission data held by the center device/device 3 in response to a request from the host computer 1. It is also possible for the center device 3 to detect changes in data transmitted using these NUN transmission methods and transmit them to the higher-level calculation ia1. The method of transmitting N and NUN will be explained below. 1:N sent by the center device 3 in FIG. 6 (1)
An example of the transmission format of the transmission method is shown below. The center device W3 first transmits block address data including a block address and data indicating that 1:N block communication should be started. Note that the block address here refers to an address assigned to a group (block) of a predetermined number of addresses of the terminals 4 (however, each terminal address within this group is ordered in advance). The block address data is received by all terminals, and terminals with addresses belonging to this block address are placed in a receiving state. Next, the center device 3 sequentially transmits output data for terminal addresses 0-1-2 -------7 and 8 addresses, and these output data are received by the terminal that matches its own address and It is output from the terminal 4 as an output signal 7. The output data for each terminal address includes parity for preventing transmission errors, data for zamchae-seok, etc., and is configured so that when a data error occurs, the received data can be ignored. Conversely, when the center device 3 receives input data as the input signal 6 from the terminal 4, it specifies the block address to be communicated as shown in the transmission formant example in FIG. 6(2). As a result, similarly to the above, the terminals 4 whose addresses belong to the block address in question sequentially transmit in order of address O→1→2 . . . --→ 7. if,
When the terminal at the previous address does not transmit, the terminal at the next address waits for a certain period of time, confirms that no transmission is occurring, and then transmits the input data. This time is shortened in descending order of addresses (it is set to L, so that the terminal with the later address can always transmit when the previous address is not transmitting.Configured like this In particular, even if the terminal in use skips over the middle of the address, it is designed so that failures do not occur due to missing numbers in the address.In addition, data transmission between the terminals 4 is devised. (N:N transmission), the transmission format shown in Figure 6 (2) is used as is.In this case, the data transmitted by the terminal is simply a terminal that has a specific address relationship with the transmitting terminal. At the same time, the center device 3 monitors these transmission data and sets the data in the center device's RAM.The transmission format shown in Fig. 6 shows the case of block communication. However, in addition to this, communication performed for each individual address is also used. Fig. 7 is an explanatory diagram of an example of arranging terminal data owned by the center device in the RAM. In this example, the terminal address is , if the maximum number of terminals is 64, addresses 1, 2
, −−−−−−−−−. Up to 64 terminals are provided, and the input data of these terminals is sequentially stored in the RAM by the CPU in the center device. In the example shown in Figure 7, the input data length of the terminal is 32 bits, so Dfo+
Di+, Di, , Di each have 8 bits, meaning a total of 32 bits of data. In addition, if the condition of the terminal is abnormal, such as when data transmission is impossible between the center device and the terminal, or when the analog input amount of the terminal is outside the specified range (for example, a signal circuit is disconnected), the terminal Since failure data is sent from the CPU, it is similarly set as status data by the CPU. Whether the center device uses the 1:N transmission method or the NUN transmission method, all transmitted data is received by the center device, so input data from all terminals is sent to the center device's RA.
On the other hand, since terminal data is received by the center device each time it communicates with a terminal, the center device stores the previously received terminal data (Di data) that it already owns in Figure 7. ), check whether there is a change, and then update the corresponding Di data in Figure 7. If there is a change, the terminal in question monitors the change in the input data as described below. It is checked whether the terminal is registered as a terminal (also called a change terminal), and if it is registered, the change data of the configuration as shown in FIG. 8 is stored in the RAM in the center device.
(also called change memory). In this case, if the terminal data input by the center device is a digital signal, multiple verification (for example, data is established when the data matches three times in a row), or if it is an analog signal, there is a restriction on the width of change. L
, it is possible to directly compare the data received by the center device. Each storage area of change data in FIG. 8 contains the address of the terminal (one of the change terminals) that the center device has determined has actually caused a data change, and the input data DioxD of the terminal.
In addition to is, failure data sent from the terminal is stored in the status data area. Additionally, communication abnormalities for each terminal address determined by the center device are also set as status data. FIG. 9(a) is an explanatory diagram of how to use these change data RAM (change memory). The change data is stored in the change memory in the order of occurrence in the order in which any change is detected. However, the changed data of all the terminals is not stored, but only the changed terminals are stored. In this case, the change data is stored in the data area next to the value of the change data set counter (CNT) in FIG. Change data (1) ~ (
The data up to II) are stored sequentially, and this floor indicates change data GNT, and if CNT reaches n, it is stored again as change data (1) and is used repeatedly. If there is unsent data in the change data, the change data is sequentially sent from the center device to the host computer, but the CNTO value of the sent change data is stored in the change data transmission CNT in FIG. 9 (1)). The value of this CNT is incremented by 1 each time it is transmitted. Note that a new problem arises when the registration of a changed terminal as described above is cancelled. This is a case where there is unsent change data in the host computer, and among the unsent change data there is change data of a terminal whose registration as a change terminal has been canceled. This means that after a terminal with a certain address is canceled as a changed terminal, the changed terminal data is sent from the center device. Indeed, if it is just a single cancellation, it would be easy for the host computer to ignore this change data. However, under certain conditions, the registration as a changing terminal is canceled, and if the following conditions occur and a subsequent change of terminal data is requested with the same terminal as a changing terminal, When transmission data is sent after re-registration, the host computer cannot determine whether it is data that has changed from the previous registration or data that has changed since the re-registration, causing an erroneous judgment in the host computer. For this reason, a sent flag F is provided in the changed data in FIG. 8, and if there is data of a terminal whose registration has been canceled as a changed terminal among the unsent terminal data, the sent flag F is set. transmission of the changed data to the host computer is prohibited. This sent flag F is used to prevent past unsent changed data from being sent even if the host computer requests the current terminal data that was registered as a changed terminal before the changed data. Additionally, if there is change data for the same terminal address, the sent flag F is set and subsequent transmissions are prohibited. These variable terminals can also be applied to terminals in an N:□N transmission system between terminals. In other words, the terminal data that is being monitored by the center device can also be constantly monitored and the terminal data can be transmitted from the center device to the host computer, so the host computer can also freely monitor NUN transmission data and detect abnormalities, for example. It is also possible to take appropriate measures when a situation occurs. Also, the change data I? in Figure 8? Since changes in terminal data and the occurrence of failures are set in chronological order, it can be used as important data when examining system behavior in the event of an abnormal condition. For this reason,"
1st place! 14 When the center device receives a change data dump instruction (command) from W, a, it sends the unsent change data to the host computer in the order in which it was sent in the past, thereby identifying the cause of the abnormality on the host computer side. It is possible to investigate. By configuring as described above, terminal data can be monitored in the center device every time there is communication, and can be transmitted to the host computer with priority compared to other communication data. In such a transmission system, for example in an FA factory, if the emergency switch signal is activated and can be transmitted preferentially over other signals, the host computer will receive the emergency switch signal level via the center device every time. Since there is no need to do this, the processing capability of the host computer can be significantly reduced. However, in this transmission system, there is a problem that the host computer 1 becomes too busy as described below, and as a result, the transmission of necessary data from the host computer to the change terminal is delayed. 1) Changes in terminal input data are captured in the form of input data, but there are many input data that do not pose a problem in themselves;
It is desirable to detect a change in an arbitrary bit signal in the terminal input signal 6, such as when a bit signal such as W is generated, and the terminal input signal 6 is desired to be transmitted at a particularly high speed. 2) Analog quantities such as rotation speed, voltage, and current. When temperature, etc. is transmitted as a terminal input signal, the host computer detects whether the terminal input signal has reached a specific upper limit or lower limit, or has changed by a predetermined hysteresis, rather than the continuously changing terminal input signal. It is important to detect whether or not this has occurred. 3) When detecting a change, there are cases where it is desired to simply detect a change, rather than requesting data transmission every time an input signal changes. In this case, the host computer first registers the terminal as a changing terminal,
When the changed data of the terminal is received, it is necessary to make a logical judgment as to what has changed in the changed data, and if as a result, the changed data after that is no longer needed, communication must be conducted to cancel the registration as the changed terminal. Otherwise, the program on the host computer side becomes complicated. 4) When the host computer receives changed data as described above, makes a logical judgment, and then cancels the registration, new changed data will be generated during the processing time.

[Purpose of the invention]

The present invention eliminates the above-mentioned problems, further divides the specification of the change conditions of the terminal change data that the host computer wants to receive, and makes it possible to specify to detect only when a specific situation changes. Furthermore, it is an object of the present invention to provide a data transmission system in which the effective period of change detection on the center device side can also be specified.

[Key points of the invention]

The main points of the present invention include a center device that controls data transmission and has the function of receiving data from connected terminals, a plurality of terminals connected from the center device via a transmission path, the center device and a bus. In a data transmission system composed of host computers connected via a data transmission path, the host computer is provided with address data of a terminal whose terminal data should be detected, and the address data of the terminal whose terminal data should be detected. A predetermined 1 in the input digital data to
Or command data to the effect that one or both of changes from H to L, or from ■ to H for multiple bit data should be detected, or (and) a predetermined upper limit value for input analog data to the terminal, or Command data (detection designation code, etc.) indicating that change detection should be performed to one or both of the lower limit values and a value that is a predetermined hysteresis value away from the upper and lower limit values, and the change detection described above is performed once. Means for transmitting data specifying whether the data is to be changed for a limited time or repeatedly (one-time change code, permanent change code, etc.); provided in the center device, and among the terminal data received by the center device, the terminal address data is transmitted from the host computer. Means (such as a CPU) for detecting the change in the data of the terminal specified by is also provided in the center device,
The present invention is provided with means (such as a CPU) for transmitting the terminal data to the host computer when the change is detected.

[Embodiments of the invention]

The present invention will be described in detail below based on FIGS. 1 to 3. FIG. 1 is a diagram showing the structure of detection designation command data sent from a host computer to a center device as an embodiment of the present invention, FIG. 2 is a diagram showing the types and contents of the detection designation command, and FIG. 3 4(1) is a diagram similarly showing the communication sequence between the center device and the host computer, and FIG. 4(2) is a diagram illustrating the setting values for detecting changes in terminal analog data. FIG. 2 is a diagram showing a conventional communication sequence corresponding to FIG. In the present invention, the transmission data transmitted from the host computer 1 to the center device 3 includes the above-mentioned terminal operation signal, that is, the transmission of output data to the terminal 4 from the host computer to the center device, or the input data of the terminal 4. In addition to the signal to be sent from the center device to the host computer, detection designation command data 50 as shown in Figure 1 is newly added, and based on this command data, the center device checks the contents of the terminal change data. , Only when a predetermined change occurs, the terminal data at that time is transmitted to the host computer. In FIG. 1, 51 is data indicating that this transmission data is detection specification command data, and 52 is a registration/deletion command, which newly registers that this transmission data 50 should check terminal change data. 53 is a detection designation code as described in FIG. 2, and 54 (54-1, . . . 54-n.) is for each terminal. Data is 54 a (54a1
~54an) is the address of the terminal to be monitored for changes in input data, and 54b (54b1~54bn) is setting data for tweeting to the corresponding terminal, which will be described later. Next, in FIG. 2, numbers 1 to 27 are numbers indicating the type of detection designation code 53, 61 is the content of the code 53,
53 (53a, 53b) is the detection specification code 532
is a designation code (also referred to as a permanent change code) indicating that the terminal data should be repeatedly transmitted from the center device 3 to the host computer 1 every time a change in the terminal input data occurs;
53b, the change in the terminal input data occurred once, and the terminal data was sent from the center device 3 to the host computer, so it is unnecessary to send the terminal data to the 1st place 111[machine] from now on. Please specify to indicate that! - code (also referred to as a one-time change code). Detection designation code 53 (value 1
0H to 12H or 90H to 92H) indicates that the predetermined bits described below in the terminal input data are H-L or L→H.
When there is a change in L -1 (or H - L), it means that the terminal data should be sent to the host computer, and in this case, the command data 50 in Figure 1 In the terminal address 54a, the address of the terminal to be monitored is stored, and in the setting data 54b corresponding to the address 54a, data indicating the bit position of the monitoring target in the input signal 6 of the terminal is stored. Next, the meaning of the detection designation code 53 (values 20H to 27H or AOH to A7H) in teeth 4 to 11 in FIG. 2 will be explained with reference to FIG. 3. In FIG. An example of the temporal transition of the analog data 70 is shown, where L is one type of analog data (such as temperature) and time is plotted on the horizontal axis. 71 (described later), t2 is the terminal control signal (for example, ON10 F) of the first computer 1 at time t1.
The analog data 70 enters a descending process based on the F command, etc.) and falls below the return value 73, which is a preset 1 hysteresis value 72 (described later) from the limit value 71. Now, each of the detection designation codes 53 (Ilh4 to 11) corresponds to the upper limit value 71 (1 point) corresponding to the terminal analog data 70 that is subject to change monitoring. The time point tl when the upper limit value 71 is exceeded (set for each detection code), and the corresponding hysteresis value 72 (this value is given for each detection designation code in Fig. This is a code that indicates that the input data of the terminal should be transmitted from the center device 3 to the host computer 1 at the time t2 when the value falls below by .). Detection designation code 53 in Fig. 2 IIkl12-19
(value 30H to 37H or BOH to B7H) is No,
Similarly to the same designation codes 53 of 4 to 11, the lower limit value (1 point, this value is set for each address 54a of the target terminal in the setting data 54b in FIG. 1) corresponding to the terminal analog data to be detected. ), and the corresponding hysteresis value (
This value is given for each detection designation code value in FIG. 2, and a total of 8 levels of values can be selected. ) is a code that indicates that the terminal data should be sent to the host computer at the time when the terminal data exceeds the limit. Also, the detection designation code 53 (
The values 40H to 47H or C0H to C7H) correspond to the terminal analog data for which change is to be detected.'2 limit value and lower limit value (total of 2 points, these two values are the data 54 for each terminal in Figure 1) The data part corresponding to the setting data 54b is added for each word by one word. The terminal data should be sent to the host computer at the point when the value changes by the amount (L given for each detection designation code in Figure 2), in the same way as above. This is the code. By receiving the detection designation command data 50 including the detection designation code 53 as described above from the host computer 1, the center device 3 repeats N communications with the terminal 4 and responds to the terminal input data sent from the terminal. , previous 1t1. !
(Determination of the presence or absence of a change determined by designation I F1a) Performs an i-check, and immediately transmits the child terminal input data to the computer 1 at the 1st position at the time when the corresponding change occurs. -1- position dI calculator 1 thereby sends control data (ON, OFF commands, etc.) to the corresponding terminal to the center device w3, so that the center device 3 then sends the control data to the corresponding terminal 4 in the next N communication. Send data. An example of such a communication sequence between the host computer 1 and the center device 3 is shown in FIG. 4+11. The data input on the center device side (O, ) in the same figure means the reception of changed terminal input data, and the data judgment means the data judgment given by the detection designation code 53. In the present invention, the data is transferred to the host computer 1 only when it is determined in this data judgment that there has been a change corresponding to the specified code 53. As a result, the host computer 1 performs the necessary control processing and transfers the control data. Center device 3
Send to. The center device 3 outputs this control data to the terminal side. In this way, since the host computer communicates only lean data with the center device, the burden of terminal control processing on the host computer can be reduced and the control response speed can be increased. On the other hand, in the conventional method shown in FIG. 4 (2), each time the center device 1 receives terminal change data, it is sent to the host computer 2, and the host computer 2 checks whether there is a necessary change in the received data. Since the judgment is made each time, the judgment process becomes busy and the necessary control response operation becomes slow. Note that A in the figure indicates the time during which the host computer 1 can execute processes other than this terminal control process, and it can be seen that the time A can be made larger in the figure (1).

【Effect of the invention】

As is clear from the above description, according to the present invention, the host computer sends a command including necessary change condition setting data for terminal data to the center device in advance, and changes the terminal input data that the center device receives from the terminal. The center equipment, which has more time than the host computer, carries out the process of determining whether or not there is a predetermined change in the digital value or analog value that is meant by this setting data, and only when there is a change, the central equipment has more time than the host computer. Since terminal input data is received from the center device and the corresponding control data is given to the terminal via the center device, the burden of terminal control processing on the host computer and the program execution time are reduced, and it is possible to reduce the burden of terminal control processing on the host computer In addition to increasing the execution time of program processing and speeding up the processing time, terminal input data is immediately compared in the center device and the results are transmitted to the host computer, allowing for more detailed processing. Terminal input data can be checked. In addition, since changes in terminal input data can be transmitted only once, data processing on the host computer side can be simplified by eliminating unnecessary data transmission to the host computer. be.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the configuration of detection designation command data as an embodiment of the present invention, FIG. 2 is a diagram showing the types and contents of the detection designation command, and FIG. 3 is a diagram showing the type and content of the detection designation command. Diagram explaining setting values for change detection, No. 4
Figure (1) also shows the communication sequence between the host computer and the center device, Figure 4 (2) shows the conventional communication sequence corresponding to Figure 11, and Figure 5 shows the communication sequence of the present invention and the conventional one. A configuration diagram of an example of a data transmission system, FIG. 6 is an explanatory diagram of an example of a transmission formant, FIG. 7 is an explanatory diagram of an example of arrangement of terminal data owned by a center device in RAM,
Figure 8 shows the change data RAM also owned by the center device.
The example configuration diagram, FIG. 9, is also an explanatory diagram of an example of how to use the change data RAM. 1: Host computer, 2: Transmission line, 3: Center device, 4 (
4-1, ~, 4-n): Terminal, 5: Signal path, 6: Input signal, 7: Output signal, 50: Detection specification command data, 5
3: Detection specification code, 53a: Permanent change code, 53b
: One-time change code, 54 (54-1, 〜, 54-n)
:Terminal bone data, 54a (54a1-54an)
:Terminal address, 54b (54bl~54bn)
: Setting data, 71: Upper limit value, 72: Hysteresis value. 5Ω: Saikai Kuri 10 Stations Command 2 A, Data for 2 Terminals 71 Figure, 3t-3 Figure 53: Oai Yaguchi Sai 1λ Koko F U← 9 People 4 /Jl:, f2! d Off figure) O9 figure

Claims (1)

[Scope of Claims] 1) A center device that controls data transmission and has the function of receiving data from connected terminals, a plurality of terminals connected from the center device via a transmission path, and the center device. In a data transmission system consisting of host computers connected via a data transmission path, the host computer is provided with the address data of the terminal whose terminal data should be detected, and the address data of the terminal whose terminal data changes are to be detected, to the center device. Command data or (and) input to the terminal to the effect that one or both of changes from H to L or from L to H should be detected for predetermined one or more bit data in input digital data to the terminal. Command data to the effect that a change in analog data should be detected to a value that is a predetermined hysteresis value away from one or both of a predetermined upper limit value or a lower limit value, and the above-described change detection. A means for transmitting data specifying whether to be carried out only once or repeatedly; provided in the center device; and among the terminal data received by the center device, data of the terminal specified by the terminal address data from the host computer. A data transmission system comprising: means for detecting the change; and means, also provided in the center device, for transmitting the terminal data to a host computer when the change is detected.