Patent Application
20080078189
Other objects, features and advantages of the present invention will be apparent from the following detailed description when read in conjunction with the accompanying drawings.
A description will be provided of the preferred embodiments of the present invention with reference to the accompanying drawings.
In the following, unifying different communication networks means that the different communication networks are linked together so that communication between the networks can be performed using a common communication protocol. For example, it means that the main buses of the two communication networks are combined together to form a common main bus, and communication between the networks on the common main bus is performed using the common communication protocol.
As shown in
A master controller (master device) 5 and a plurality of devices (slave devices) 6 which form the communication network of master system 3 are connected to the common main bus 4. And a cryopump system controller (local slave device) 7, a plurality of cryopumps (local slave devices) 8, and a plurality of compressors (local slave devices) 9 which form the communication network of cryopump system 2 are also connected to the common main bus 4.
When two or more cryopump systems 2 are needed for the communication network system 1 of
In the communication network system 1 of this embodiment, the master system 3 can acquire information related to the status and processes of the cryopump system 2 directly and in real time. Moreover, using one communication line between the cryopump system 2 and the master system 3 is adequate for the communication network system 1 of this embodiment, and the cost can be reduced.
As shown in
The communication unit of the master controller 5 performs communication between the master controller 5 and the cryopumps 8 or the compressors 9, and performs communication between the master controller 5 and the cryopump system controller 7. The control unit 13 receives the status information of each of the slave devices (the cryopumps 8 and the compressors 9) using the communication unit. And the control unit 13 transmits the command information from the registers 12 to each of the slave devices (the cryopumps 8 and the compressors 9) using the communication unit.
It is preferred that each of the slave devices (the cryopumps) 8 includes a memory unit 21 for storing the table-format status information 11a and the table-format control information 11b, and each of the slave devices (the compressors) 9 includes a memory unit 22 for storing the table-format status information 11c and the table-format command information 11d, as shown in
The master controller 5 serves as a master device in the master system network which manages the information in the master system network. The master controller 5 performs an intermediary task which manages the transmission and receiving of the status information and the command information between the cryopumps 8 (or the compressors 9) and the cryopump system controller 7. Moreover, the master controller 5 manages the transmission and receiving of system status information and command information between the master controller 5 and the cryopump system controller 7.
Each of the cryopumps 8 comprises a cryopump body (not shown), the memory unit 21, an operation unit (not shown), and a communication unit (not shown). The operation unit of each cryopump 8 operates the cryopump body in accordance with the table-format command information received from the master controller 5. The memory unit 21 includes a status memory area in which a pump status table (the status information 11a) is stored, and a command memory area in which a pump command table (the command information 11b) is stored.
Each of the cryopumps 8 receives the pump command table from the master controller 5 using the communication unit, and stores the pump command table into the memory unit 21. And the cryopump 8 reads the pump command table from the memory unit 21 and controls the cryopump body in accordance with the read pump command table. Then, the cryopump 8 writes measurement data of respective components of the cryopump body as a result of the control, to the pump status table 11a in the status memory area. The contents of the pump status table are updated to keep the latest status of the cryopump 8 concerned. The cryopump 8 transmits the status information 11a (the pump status table) to the master controller 5 in response to a call of status information request sent from the master controller 5.
An example of the pump status table (the status information 11a) is as follows:
the frequency of the pump of the refrigeration unit (F(Hz));
the temperature of the first stage (T1(K));
the temperature of the second stage (T2(K));
the internal pressure (P(mTorr));
the operating condition (Status); and
other variables (Parameter).
An example of the pump command table (the control information 11b) is as follows:
the command frequency (F(Hz));
the operating condition of the motor (Motor);
the rough valve (RV);
the purge valve (PV); and
other variables (Parameter).
Each of the compressors 9 comprises a compressor body (not shown), the memory unit 22, an operation unit (not shown), and a communication unit (not shown). The operation unit of each compressor 9 operates the compressor body in accordance with the table-format command information received from the master controller 5. The memory unit 22 includes a status memory area in which a compressor status table (the status information 11c) is stored, and a command memory area in which a compressor command table (the command information 11d) is stored.
Each of the compressors 9 receives the compressor command table from the master controller 5 using the communication unit, and stores the compressor command table into the memory unit 22. And the compressor 9 reads the compressor command table from the memory unit 22 and controls the compressor body in accordance with the read compressor command table. Then, the compressor 9 writes measurement data of respective components of the compressor body as a result of the control, to the compressor status table 11c in the status memory area of the memory unit 22. The contents of the compressor status table are updated to keep the latest status of the compressor 9 concerned. The compressor 9 transmits the status information 11c (the compressor status table) to the master controller 5 in response to a call of status information request sent from the master controller 5.
An example of the compressor status table (the status information 11c) is as follows:
the upper-limit pressure (PH(MPa));
the lower-limit pressure (PL(MPa));
the frequency of the motor of the compressor (F(Hz));
the opening ratio of the bypass valve (V(%));
the operating condition (Status); and
other variables (Parameter).
An example of the compressor command table (the control information 11d) is as follows:
the command frequency (DP(Hz));
the operating condition (Run/Stop); and
other variables (Parameter).
The cryopump system controller 7 comprises a memory unit, a host control unit 16, and a communication unit (not shown). The memory unit of the cryopump system controller 7 includes the pump status table 11a, the pump command table 11b, the compressor status table 11c, the compressor command table 11d, a master-controller command table 14 (in which command information received from the master controller is stored), and a system status table 15 (which indicates the status of the cryopump system controller 7).
It is preferred that, except the master-controller command table 14 and the system status table 15, the memory unit includes a corresponding number of the pump command or status tables for the number of the cryopumps 8 included in the cryopump system 2, and includes a corresponding number of the compressor command or status tables for the number of the compressors 9 included in the cryopump system 2.
The host control unit 16 is constituted by a processing unit, such as a microprocessor. The host control unit 16 generates system status data which indicates the status of the cryopump system controller 7, and stores the generated system status data into the system status table 15. The host control unit 16 accesses the master-controller command table 14 in which the command information received from the master controller 5 is stored, reads the command information from the master-controller command table 14, and changes the processing operation of the host control unit 16 in accordance with the read command information.
After the processing operation of the host control unit 16 is changed, the host control unit 16 accesses the pump status table 11a and the compressor status table 11c to acquire the necessary data. The host control unit 16 performs a processing operation based on the acquired data, to generate the pump control data and the compressor control data, and stores the pump control data and the compressor control data into the pump command table 11b and the compressor command table 11d in the memory unit.
By using the communication unit, the cryopump system controller 7 receives, from the master controller 5, the command information, the pump status information and the compressor status information, and stores them into the corresponding tables 14, 11a and 11c of the memory unit, respectively. Moreover, by using the communication unit, the cryopump system controller 7 transmits, to the master controller 5, the data of the system status table 15, the data of the pump command table 11b and the data of the compressor command table 11d, in response to a call of status information request sent from the master controller 5.
As shown in
As shown in
Accordingly, the communication network system of the present embodiment is configured to be a single-master system in which each of the respective components and the master controller 5 performs a one-to-one communication therebetween. What is required for the master system 3 is to have the register function to store temporarily the status information of the cryopumps 8 and the compressors 9. The software included in the master controller 5 can be simplified, and the development period can be reduced remarkably.
The command information transmitted to the cryopump system controller 7 by the master controller 5 primarily includes a stop/start command to the slave devices (the cryopumps 8 and the compressors 9) in the cryopump system 2.
The communication between the master controller 5 and each of the slave devices in the communication data flow of
The master/slave system method is a method of communication to transmit and receive the status information and to transmit and receive the command information. The master/slave system method typically includes the following phases (1) to (5).
(1) The master controller 5 performs polling to the slave devices. In this step, the command information is transmitted from the master controller 5 to the corresponding one of the slave devices, and the status information is transmitted from the corresponding slave device to the master controller 5.
(2) The master controller 5 transmits a bit-strobe request to the slave devices. The message portion of the bit-strobe request includes an output data consisting of a number of bits (e.g., 64 bits or 8 bytes). Each of the bits is assigned for the MAC (media access control) ID (0, . . . , 63) on the network. Bit-strobe responses are returned to the master controller 5 from the corresponding nodes (slave devices).
(3) Each of the slave devices transmits the status information to the master controller 5 upon occurrence of an event.
(4) Each of the slave devices transmits the status information to the master controller 5 at intervals of a predetermined time which is set up by the user.
(5) The master controller 5 transmits to each of the slave devices a message which enables an operation command to be given to each slave device. For example, the message may include the address (the ID of the physical layer), the controlled object (class ID) and the service code (one-attribute data readout).
The peer-to-peer network method is a method of communication to transmit and receive messages for performing setting or diagnostic process of the slave devices.
The unified communication network for use in the communication network system in the embodiment of the invention may be constructed using any of various communication protocols including Devicenet protocol, Ethernet protocol, CC-link protocol, RS-485 protocol, and GPIB (general purpose interface bus; IEEE488) protocol.
Devicenet is a type of field network in which sensors, devices and controllers in a wide range of the field, excluding computers, are interlinked through a digital communication network. By using Devicenet, communication between various controlled devices can be easily realized in one network. A host device, such as a personal computer, can be connected as a master device. Sensors, actuators, I/O devices, gateway units and processing units can be connected as slave devices. Use of Devicenet allows reduction of the amount of wiring, such as I/O wires, analog signal lines, RS232C cables, RS422 cables, or other communication lines. Simplification of the wiring operation is possible.
The communication network system in the above-described embodiment is applicable to systems which require unifying of different communication networks. It is preferred to apply the communication network system in the above-described embodiment to a cryopump communication network for use in a semiconductor fabrication device in particular.
The present invention is not limited to the above-described embodiments, and variations and modifications may be made without departing from the scope of the present invention.
