JP2004096477A - Signal converter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To connect a device like a highly reliable interlock, easily to a network and to add another function easily. <P>SOLUTION: The signal converter for obtaining information at each node connected to a network includes a network interface unit mounted as a hardware for obtaining a frame from the network, a controller unit for taking out prescribed data from the obtained frame, and an output unit for generating the taken-out analog and digital data. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a signal converter that can extract a predetermined signal from each node in a communication network, particularly a device network, and can easily add functions without changing the system configuration.
[0002]
[Prior art]
In recent years, in semiconductor production and the like, a so-called device net has been used for controlling production facilities. This device net is a master-slave type or command response type network, and controls each slave by transmitting / receiving a command between the master and the slave.
[0003]
In such a method, each node is usually given a node address called a network resource. Generally, network resources are limited in a network, and thus the number of nodes that can be connected to the network is limited.
[0004]
On the other hand, each slave is controlled by a control signal transmitted between the master and the slave. Therefore, when the control of the slaves is performed frequently, or when a large number of slaves are controlled simultaneously, the network may be congested.
[0005]
Furthermore, the networking of equipment such as production equipment conventionally allowed the state of each apparatus, such as the pressure, temperature or actuator state in the chamber, to be directly read out from the output terminal attached to the apparatus. On the other hand, since each of these data is stored in a frame according to the communication protocol, it is difficult to directly read the data.
[0006]
Therefore, when a trouble occurs in each slave or master, it is difficult to find the problem, and there is a possibility that other devices will malfunction. In this case, the command is not normally transmitted between the master and the slave, and there is a risk that the network may be paralyzed.
[0007]
Therefore, it is necessary to monitor the state of each node in the network. On the other hand, as a device for monitoring data flowing in a network, a monitor / logging device is disclosed in JP-A-2000-216798.
[0008]
In the device network, predetermined data is extracted from a frame flowing in the network and displayed on a display device. The monitor and logging device is implemented as Windows (registered trademark) software. This is an apparatus using a personal computer.
[0009]
In this case, there is a problem of operation instability inherent in Windows (registered trademark), a bug in application software, an operation instability due to a problem of compatibility between Windows (registered trademark) and computer hardware, and other computers known today. The monitor / logging device is connected to the device net while all the problems concerning the operation of the device are included.
[0010]
Therefore, due to the above-mentioned problems, it is not suitable in terms of reliability to use the monitor / logging device for functions or devices requiring high reliability, such as an interlock function in a network.
[0011]
[Problems to be solved by the invention]
As described above, a control system using a network can realize automation of production equipment, so-called FA (factory automation), while operators can manage each device and quickly respond to troubles because the entire system is a black box. There is a possibility that it will be difficult to respond.
[0012]
In view of the above problems, the present invention provides a method for acquiring and displaying data flowing in a network, adding a device requiring high reliability such as an interlock to the network, and a method for adding other functions. Suggest.
[0013]
[Means for Solving the Problems]
A signal converter for acquiring information of each node connected to the network, which is implemented as hardware, a network interface for acquiring a frame from the network, a controller unit for extracting predetermined data from the acquired frame, and a Provided is a signal converter device having analog and digital signal output units for outputting data.
[0014]
BEST MODE FOR CARRYING OUT THE INVENTION
First, an overview of the information flowing in the network and its processing will be given. In communication using a protocol such as the Internet or a LAN, information flowing in a network is configured based on a predetermined protocol, and is handled in units called frames. The frame stores data that is information to be carried, in addition to the addresses of the source and destination nodes. Each node has at least an interface unit for receiving a frame from the network and a processor unit for processing the frame.
[0015]
The interface reads an address corresponding to the physical layer of the protocol, selects necessary frames, and transmits them to the processor. The processor performs predetermined processing on the frame and extracts data from the frame. The processor unit can perform various processes, and this is implemented by a computer program.
[0016]
Further, it has a process of displaying data processed by the processor unit on a display or recording the data on a recording medium such as a hard disk.
[0017]
As described above, the frame flowing in the network is processed by the interface unit and the processor unit, and the data stored in the frame is extracted. In the processor unit, desired processing can be performed by a computer program.
[0018]
Next, the present invention will be described below with reference to the drawings. Here, the processor unit is hereinafter referred to as a controller unit. FIG. 1 is a schematic block diagram showing the configuration of the signal converter 1 of the present invention. In brief, the flow of the process is as follows. A frame flowing in the network 40 is captured by the interface unit 10 and transmitted to the controller unit 20. The controller unit 20 extracts predetermined data, and outputs the data from the output unit 30.
[0019]
In the figure, in the present invention, the controller unit 20 is implemented as hardware, and usually includes an IC, an LSI, and the like, and the computer program includes a ROM (including a rewritable nonvolatile memory such as a flash memory and an EPROM) or the like. Is recorded in a read-only memory. Further, the output unit 30 can output analog and digital signals, and thus includes a D / A converter, a decoder, and an amplifier.
[0020]
Next, the operation of the signal converter 1 of the present invention will be described. In FIG. 1, a command which is a control signal for controlling the slave exists in the network in addition to the frame. Therefore, the interface unit 10 selects and acquires only a frame from all information flowing in the network, and transmits the frame to the controller unit 20. The controller 20 decodes the frame according to the protocol and extracts the data. The data is transmitted to the output unit 30, is reconstructed into data of an appropriate format by a D / A converter or a decoder in the output unit, and is output from the terminal. The controller unit 20 has a configurator 23 as shown in FIG. 2, which will be described in detail later. When a user designates an arbitrary node using an I / O device, a program operating in the controller unit 20 is executed. Transmits the data of the corresponding frame to a predetermined output terminal of the output unit 30 according to the contents of the configurator.
[0021]
Next, the configuration and operation of the controller unit 20 will be described. In the present invention, the controller unit 20 is implemented as hardware, and FIG. 2 shows an example thereof. As shown, the controller unit 20 includes a CPU 21 for processing the data, a memory 22 in which a program is stored as a ROM, and a configurator 23 for setting parameters such as designation of a node. Further, an I / O device 50 for displaying the input to the configurator 23 and the set contents is also provided.
[0022]
In FIG. 2, a program for processing a frame is stored in the memory 22 as a ROM as described above, and the CPU 21 decodes a header of the frame according to the program, and acquires data from a data area in the frame. I do. The acquired data is transmitted to the output unit 30. Here, the user can arbitrarily designate an output terminal of the output unit 30, and inputs necessary information to the configurator 23 using the I / O device 50. Therefore, the program running in the CPU 21 transmits an output control signal to the output unit 30 according to the contents of the configurator.
[0023]
Finally, the output unit 30 outputs data to a corresponding output terminal based on the output control signal transmitted from the controller unit 20.
[0024]
As described above, in the present invention, the program is stored as the ROM, and does not require an operating system unlike a personal computer. Therefore, it is possible to eliminate risks such as a malfunction of the operating system, rewriting of the contents of the memory by the user, and erasing of the program due to an incorrect operation.
[0025]
As described above, a so-called Neumann computer with a built-in program has been exemplified as the controller unit. However, embodiments of the present invention are not limited to this. For example, a processor that implements a data processing algorithm as a logic circuit, a so-called hardware Wired logic can also be used. In this case, changing the algorithm requires replacement of the processor itself, but the operational reliability can be further improved.
[0026]
Next, a method of adding a function using the signal converter will be described.
[0027]
As described above, the signal converter according to the present invention avoids a decrease in reliability due to the use of a personal computer, and ensures reliable operation. Further, since the signal converter is a passive device with respect to the network, it does not require network resources, and therefore can easily connect the signal converter without changing the network system. Therefore, a function can be easily added to the network by connecting an additional device to the signal converter. Next, a specific method will be described using an interlock.
[0028]
FIG. 3 shows a schematic diagram. Each node 60 is connected to the network 40, and further connected to the signal converter 1 of the present invention. As described above, since the signal converter is a passive device, there is no need to change the system such as allocating network resources when connecting to the network. Therefore, it is possible to directly connect to the current network. Therefore, when connecting another device to the output terminal of the signal converter, no network resource is required. Thus, the interlock can be connected to the output terminal of the signal converter without using network resources.
[0029]
When the signal converter and the interlock are operated in this state, the interlock 2 monitors the output from the signal converter as described above. At this time, if a signal is excessively transmitted in the network due to, for example, a trouble in a certain node, the network is crowded and paralysis occurs. In this case, the interlock acquires the signal output from the signal converter, detects an abnormality in the network, and shuts down the network, thereby avoiding a malfunction of another node. In this case, the interlock shuts off the common power supply to the nodes connected to the network. Alternatively, when each node is distributed to a plurality of power supplies, the power supply corresponding to the problematic node is shut off. However, the function of the interlock is not limited to this.
[0030]
FIG. 4 shows another embodiment of the present invention. As shown, the alarm device 3 is connected to the output terminal of the signal converter. As a result, if the alarm device 3 is, for example, a temperature detection alarm, the information of a specific node is output to a specific output terminal by the above-described I / O device 50, and a temperature detection alarm is connected to the terminal. For example, abnormal heating of the heater in the chamber can be detected. However, the present invention is not limited to temperature detection, and a monitoring device for monitoring the pressure in the chamber, the state of the actuator, and the like can be connected.
[0031]
In FIG. 5, a personal computer 4 is connected to the signal converter 1, so that the state of each node can be displayed by computer graphics or the like with good visibility using the processing capability of the personal computer. The influence on the network due to the malfunction of the personal computer itself can be cut off. Further, detailed data analysis can be performed in real time using various application software.
[0032]
Further, data logging can be performed by connecting data recording means to the signal converter. Normally, data logging can be performed on a hard disk of a personal computer, an optical or magnetic disk, or the like, but is not limited thereto. Further, the present invention can be applied not only to a device net but also to all networks using a protocol.
[0033]
【The invention's effect】
By using the signal converter of the present invention in a network such as a device net, a device requiring extremely high reliability such as an interlock can be connected, and network resources are not consumed and the load on the network is reduced. Other functions can be added without adding a function.
[Brief description of the drawings]
FIG. 1 is a block diagram of a signal converter of the present invention.
FIG. 2 is a block diagram of a controller unit of the signal converter of the present invention.
FIG. 3 is a block diagram in which the signal converter of the present invention is connected to a network and further connected to an interlock.
FIG. 4 is a block diagram in which the signal converter of the present invention is connected to a network and further an alarm device is connected.
FIG. 5 is a block diagram in which the signal converter of the present invention is connected to a network and further connected to a personal computer.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Signal converter 2 Interlock 3 Alarm device 4 Personal computer 10 Interface unit 20 Controller unit 30 Output unit 40 Network 50 I / O device 60 Each node

Claims (5)

A signal converter for acquiring information of each node connected to the network, a network interface unit for acquiring a frame from the network, a controller unit for extracting predetermined data from the acquired frame, and an output unit for outputting the extracted signal data. Signal converter device. The apparatus according to claim 1, wherein the controller acquires predetermined data from a frame communicated on a network. The apparatus according to claim 1, wherein the controller unit includes a configurator, and is capable of setting parameters externally. The device according to claim 1, wherein the signal converter device can output digital and analog signals acquired by the controller unit from the output unit. A method for adding an additional function to a network using the signal converter device.

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