JP3777789B2 - Bus monitoring indicator - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a bus monitoring indicator connected to a bus line of a network and monitoring a transmission state, and more particularly to a bus monitoring indicator suitable for connecting to an automated factory network.
[0002]
[Problems to be solved by the invention]
Conventionally, when trying to monitor network transmission, the only means for realizing this is to prepare a PC-based bus monitor or look at the display element indicating the status of the master installed in the master. It was not suitable for always being attached to each network. In the latter, the amount of information was small and it was difficult to grasp the complete situation. For this reason, there has been a demand for the emergence of a bus monitoring indicator that easily grasps a network transmission state without using a bus monitor or the like, and enables early identification of a failure location.
[0003]
[Means for Solving the Problems]
In order to solve the above problems, the invention of claim 1 is directed to a receiving circuit connected to a bus line of a polling network in which a master and a plurality of slaves are connected, and receiving transmission data on the network, and the master From the request display element and the response display element respectively arranged corresponding to each address assigned to the plurality of slaves, an error display element for displaying an abnormality in data transmission, and the reception circuit. And when the data transmitted from the master to the slave is received, the transmission address is read and the corresponding request display element is turned on and the data received by the receiving circuit is monitored. Data sent from the other slave to the master within a specified time after data was sent from the master to the slave When received, the response display element corresponding to the transmission address is turned on and the data received by the receiving circuit is monitored, and within a predetermined time after the data is transmitted from the master to the slave. And means for lighting an error display element when data transmitted from the slave to the master is not received.
[0004]
According to a second aspect of the present invention, in the first aspect of the invention, an address display element arranged in parallel corresponding to the request display element and the response display element, and data contents transmitted from the master to the slave are bit A set of display elements for request data to be displayed, a set of display elements for response data for displaying bit contents of data transmitted from the slave to the master, a changeover switch provided for addressing, and the receiving circuit Storage means for storing master-slave request data and response data received in accordance with the address, and one address display element corresponding to the address designated by the change-over switch is lit up. In addition, the request data and response data corresponding to the address are read from the storage means, and the bit values are requested respectively. Characterized by comprising a means for lighting displayed over data for a display device and response data for a display device.
[0005]
According to a third aspect of the present invention, in the second aspect of the present invention, a voltage status display element for displaying a voltage drop abnormality, an operation display element for displaying that the number of occurrences of the voltage drop abnormality is being displayed, and a network bus line The voltage monitoring circuit that detects the voltage of the bus line and outputs an abnormal signal when the detected voltage is lower than the preset voltage, and counts the number of times the abnormal signal is output from the voltage monitoring circuit Counting means, a means for lighting the voltage status display element and the operation display element when an abnormal signal is output from the voltage monitoring circuit, and a display element for request / response data while the operation display element is lit And a means for displaying the count value of the counting means in a binary number.
[0006]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a diagram showing an example of a network configuration in a factory where a bus monitoring display according to the present invention is mainly used. Note that the network hierarchy for an actual factory FA is more complex than that shown. In the figure, a plurality of controllers 2 are arranged under a host computer 1 that manages the entire system, and various devices are connected as slaves 4 via the bus-type network 3 in the lowest layer with the controller 2 as a master. The
[0007]
Devices connected as the slave 4 are sensors and actuators attached to a belt conveyor and the like, and the data is periodically communicated with the controller 2 as 4-bit input / output data. The bus monitoring display according to the present invention is connected to the bus-type network 3 in the lowest layer, but only monitors the transmission and is not assigned an address as a terminal.
[0008]
FIG. 2 is a diagram showing a transmission procedure in the network 3 of FIG.
This transmission is performed by a polling method, in which the master calls a slave to which each address is allocated and returns a response to the master. The master request signal includes information on the address of the slave to be transmitted. This polling is periodically performed, and when there is no response from the slave or when polling from the master is interrupted for a predetermined time or more, it is determined that there is an abnormality or failure in transmission.
[0009]
Next, a first embodiment according to the invention of claim 1 will be described.
FIG. 3 is a diagram showing the configuration of the bus monitoring display according to the first embodiment, and FIG. 4 is an external view showing the layout of the display panel. In the figure, reference numeral 5 denotes a network bus line corresponding to the network 3 in FIG. 1, which is a network at the lowest layer of the factory network, to which a master (not shown) and a plurality of slaves 4 are connected. Connected to the network bus line 5 is a bus monitoring display 6 including a receiving circuit 7, a control circuit 8, a display element driver 9, a request display element 10, a response display element 11, and an error display element 12.
[0010]
The receiving circuit 7 is connected to the bus line 5 to receive transmission data on the network and send it to the control circuit 8. Although not shown, the control circuit 8 is constituted by a microcomputer incorporating a ROM, a RAM, a timer, and a counter, and identifies whether the data received by the receiving circuit 7 is data from the master or data from the slave. If the data is from the master, it is divided into the address of the destination slave and the input / output data. In addition, the control circuit 8 outputs a driver control signal to the display element driver 9.
[0011]
The display element driver 9 drives the display elements 10 to 12 to be turned on / off according to the input driver control signal. As shown in FIG. 4, the request display element 10 displays the presence / absence of requested transmission data from the master to the slave for each slave address (0 to 31). The response display element 11 is arranged in parallel with the request display element 10 and displays presence / absence of response transmission data from the slave to the master by lighting / extinguishing. These display elements 10 and 11 are arranged in a matrix in order of addresses. Further, an error display element 12 is installed as another display element. Further, in the vicinity of the panel surface of the display 6 main body in which the display elements 10 to 12 are arranged, the corresponding addresses and display functions are entered by printing or the like.
[0012]
Next, these operations will be described. When the transmission starts, the control circuit 8 identifies whether the data received by the receiving circuit 7 is a request sent from the master to the slave or a response sent from the slave to the master. In the case of request data sent from the master as a slave, a signal is sent to the display element driver 9 to turn on the request display element 10 corresponding to the slave address of the master, and the request display element 10 is turned on. Next, when there is a response from the slave to the master before the request is transmitted from the master to the slave at the next address, the response display element 11 corresponding to the address is turned on. If there is no response from the slave to the master within the time, it is determined that there is an abnormality on the slave side, and the error display element 12 is turned on.
[0013]
From these displays, the inspector can confirm that transmission is normally performed for the slave at the address where both the request display element 10 and the response display element 11 are lit. Further, the inspector can check whether there is a failed slave without checking all the display elements by looking at the error display element 12.
The lighting display of the display elements 10 and 11 is continued for a certain time, but is then turned off when there is no request data or response data. The timing for turning off the light is set by a timer of the control circuit 8 or the like.
[0014]
Next, a second embodiment according to the invention of claim 2 will be described.
FIG. 5 is a diagram showing the configuration of the bus monitoring display according to the second embodiment, and FIG. 6 is an external view showing the layout of the display panel. Since the second embodiment is obtained by adding a new function to the first embodiment shown in FIGS. 3 and 4, common portions are denoted by the same reference numerals, description thereof is omitted, and newly added. The part which was done is demonstrated. In this embodiment, an address display switch 13 is newly provided corresponding to each of the display elements 10 and 11, and an address switching switch including a push button switch used for switching the display of the display element 13 or the like. 14 is disposed.
[0015]
The address display elements 13 are arranged in a matrix like the display elements 10 and 11, and the address display elements 13 are referred to by referring to the address numbers printed on the housing of the bus monitoring display 6. It is possible to easily identify which address is indicated.
Further, request input / output data display element 16 for displaying the contents of the input / output data sent from the master to the slave, and response input / output data for displaying the contents of the input / output data sent from the slave to the master A display element 17 and a display element driver 15 for driving these display elements 16 and 17 are provided. The display elements 16 and 17 are each composed of a plurality of elements corresponding to the number of bits constituting data.
[0016]
Next, the operation will be described. The control circuit 8 performs the same control operation as that in the first embodiment, stores the master data and slave data received by the receiving circuit 7 in the internal memory for each address, and when new data is received. The memory data is updated to keep only the latest data. Next, when the changeover switch 14 is pressed, a driver control signal is output to the display element driver 9, whereby the address display element 13 corresponding to the 0 address is turned on, and when the changeover switch 14 is further pressed. The lighting position is moved to the display element 13 whose address is increased by one.
[0017]
The lighting position of the display element 13 moves in order, and when it reaches the maximum address, it returns to the 0 address. At the same time, the input / output data at the address designated by the switch 14 is read from the memory, and a driver control signal based on the contents is generated and output to the display element driver 15, so that the input / output data for request and response The bit value is lit and displayed on the display elements 16 and 17.
From the display of the contents of these data, the inspector can determine whether there is a failure in the input / output unit of the slave.
[0018]
In this embodiment, since the input / output data is 4 bits, each of the display elements 16 and 17 has a 4-bit configuration. However, if the number of bits constituting the input / output data is larger, the display elements 16 and 17 The number of elements is set accordingly. As for the data display, in addition to the bit display as binary data, a hexadecimal display using 7 segments can be used.
[0019]
Next, a third embodiment according to the invention of claim 3 will be described.
FIG. 7 is a diagram showing the configuration of the bus monitoring display according to the third embodiment, and FIG. 8 is an external view showing the layout of the display panel. Since the third embodiment is obtained by adding a new function to the second embodiment shown in FIGS. 5 and 6, common portions are denoted by the same reference numerals, description thereof is omitted, and new additions are made. The part which was done is demonstrated. In this embodiment, a voltage monitoring circuit 18 for monitoring the voltage of the network bus line 5, a bus voltage status display element 19 and a frequency display element 20 are newly provided, and the voltage of the bus line 5 is detected and the voltage value is detected. Is sent to the control circuit 8 via the input / output circuit 21.
[0020]
The input / output circuit 21 corresponds to the receiving circuit 7 in FIGS. 3 and 5 and has a similar data receiving function. The control circuit 8 determines whether or not the input voltage value is equal to or higher than a normal voltage value. If the input voltage value is lower than the normal voltage, a driver control signal for displaying a voltage drop abnormality is generated and displayed. By outputting to the element driver 9, the bus voltage status display element 19 is turned on. At the same time, the control circuit 8 counts the number of occurrences of the voltage drop abnormality, stores the count value in the buffer 8a, creates a driver control signal based on the value, and outputs it to the display element driver 15. As a result, the number of occurrences of the voltage drop abnormality is displayed on the display elements 16 and 17 as a binary number.
[0021]
When the display elements 16 and 17 display the number of occurrences of the voltage drop abnormality, the number display element 20 is turned on to distinguish it from the data display in the second embodiment. The voltage of the bus line 5 is assumed to have DC superimposed on the assumption that slave power is supplied from the bus line 5. When this voltage drops, it becomes impossible to secure the power supply of the slave, and it becomes impossible to reset or stop the slave, or to transmit the transmission data itself.
[0022]
Therefore, in this embodiment, the bus voltage is detected by the voltage monitoring circuit 18, normal / decreased is displayed on the bus voltage status display element 19 by turning off / lighting, and at the same time, the control circuit 8 counts the number of times the bus voltage has decreased. Then, the number display element 20 indicating that the voltage drop number is displayed is turned on so that the abnormality can be easily grasped. In some cases, a system that introduces a slave reset by automatically short-circuiting the bus power supply when the bus is abnormal is introduced. In that case, the stability of the system can be determined by counting the number of resets. Can know.
In addition, LED etc. are used for the display elements 10-13, 16, 17, 19, and 20 in each embodiment mentioned above.
[0023]
【The invention's effect】
As described above, according to the first aspect of the present invention, the master request transmitted on the network and the response of the slave corresponding to each address are monitored, and the result is displayed on the display element. The presence or absence of a response can be visually confirmed for each address, and a failed slave can be easily identified.
[0024]
Further, according to the invention of claim 2, by displaying and comparing the contents of the request data and the response data, even when the request / response is transmitted normally between the master and the slave, A faulty terminal whose output data is abnormal can be identified.
[0025]
Furthermore, according to the invention of claim 3, a bus short circuit accident can be detected by monitoring the decrease in bus voltage, and the number of times of abnormal decrease in bus voltage can be counted. Since the number of times the bus is short-circuited by the reset circuit can also be counted, it is possible to check whether or not the bus operation is stable.
[Brief description of the drawings]
FIG. 1 is a diagram showing an example of a network configuration in a factory where the present invention is used.
FIG. 2 is a diagram showing a transmission procedure in the network 3 of FIG.
FIG. 3 is a diagram showing a configuration of a bus monitoring display according to the first embodiment.
4 is an external view showing a layout of the display panel of FIG. 3;
FIG. 5 is a diagram showing a configuration of a bus monitoring display according to a second embodiment.
6 is an external view showing a layout of the display panel of FIG. 5;
FIG. 7 is a diagram showing a configuration of a bus monitoring display according to a third embodiment.
8 is an external view showing the layout of the display panel of FIG. 7;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Host computer 2 Controller 3 Network 4 Slave 5 Network bus line 6 Bus monitoring display 7 Reception circuit 8 Control circuit 8a Buffer 9 Display element driver 10 Request display element 11 Response display element 12 Error display element 13 Address display element 14 Address switch 15 Display element driver 16 Input / output data display element for request 17 Input / output data display element for response 18 Voltage monitoring circuit 19 Bus voltage status display element 20 Frequency display element 21 Input / output circuit

Claims (3)

A receiving circuit connected to a bus line of a polling network in which a master and a plurality of slaves are connected, and receiving transmission data on the network;
A display element for request and a display element for response respectively arranged corresponding to each address assigned to a plurality of slaves from the master;
An error display element for displaying an abnormality in data transmission;
Means for monitoring the data received by the receiving circuit, and when the data transmitted from the master to the slave is received, reading the transmission address and lighting the corresponding request display element;
Data received by the receiving circuit is monitored, and when data transmitted from the partner slave to the master is received within a predetermined time after the data is transmitted from the master to the slave, it corresponds to the transmission address Means for lighting and displaying the response display element;
The data received by the receiving circuit is monitored, and if the data transmitted from the partner slave to the master is not received within a predetermined time after the data is transmitted from the master to the slave, the error display element is turned on. Means,
A bus monitoring indicator characterized by comprising: The bus monitoring indicator according to claim 1,
Address display elements arranged in parallel corresponding to the request display elements and the response display elements;
A set of request data display elements for displaying in bits the data content transmitted from the master to the slave;
A set of response data display elements for bit-displaying data contents transmitted from the slave to the master;
A change-over switch installed for addressing;
Storage means for storing request data and response data between the master and the slave received by the receiving circuit in association with addresses;
One address display element corresponding to the address designated by the change-over switch is turned on, request data and response data corresponding to the address are read from the storage means, and each bit value is displayed for request data. Means for lighting the element and the response data display element;
A bus monitoring indicator characterized by comprising: The bus monitoring indicator according to claim 2,
A voltage status display element for displaying a voltage drop abnormality;
An operation display element for indicating that the number of occurrences of the voltage drop abnormality is being displayed;
A voltage monitoring circuit that is connected to the network bus line, detects the voltage of the bus line, and outputs an abnormal signal when the detected voltage is equal to or lower than a preset voltage;
Counting means for counting the number of times the abnormal signal is output from the voltage monitoring circuit;
Means for lighting the voltage status display element and the operation display element when an abnormal signal is output from the voltage monitoring circuit;
Means for displaying the count value of the counting means in binary on the request / response data display element while the operation display element is lit up;
A bus monitoring indicator characterized by comprising:

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