KR100460603B1 - multi-capacity 2 channel ion pump controller and vacuum measuring method using the same - Google Patents

Abstract

The controller of the present invention is a multi-capacity 2-channel ion pump controller,

And a dual port memory 80 through which both microprocessors can input and output, and the calculation microprocessor 60 includes a vacuum container. A high voltage switch 61 for controlling a high voltage generator 62 for generating a high voltage at 10, a memory 63, an EEPROM for storing channel-specific parameters, and a current detector 64 from the vacuum vessel 10. Configured to control the operation of the ADC 66 to digitize 66 the amplified and voltage converted 65 of the sensed current value, wherein the display microprocessor 70 receives parameters from the keyboard 71, Is configured to output to the display 72, and the input stage including the current detector 64 is configured to have two modules designed in a modular form to enable two-channel input, and using a multiplexer Multi-dose response, characterized by configured to receive the input analog current value is a two-channel ion-pump controllers.

Description

Multi-capacity 2 channel ion pump controller and vacuum measuring method using the same}

The present invention relates to a multi-capacity 2-channel ion pump controller and a vacuum measuring method using the same, and more particularly, it can cope with various capacities, for example, the capacity-specific characteristics of ion containers from 30 liters to 600 liters, and simultaneously Multi-capacity 2-channel ion pump controller that can measure and improve accuracy by using two low-cost microprocessors and dual port memory in advance by storing and refering the result of expensive ion pump controller in the lookup table. It relates to a measuring method.

In general, the equipment necessary to measure the internal vacuum degree of a vacuum device operating in a vacuum state such as a radiation accelerator is a vacuum gauge. In such a vacuum gauge, a vacuum pump is used to remove or inject air or a special gas into the vacuum apparatus to adjust the degree of vacuum desired by the user, and at the same time, to measure the vacuum degree through the vacuum gauge.

The vacuum measurement principle of the vacuum gauge is to apply a high pressure to the inside of the vacuum vessel to generate a forced discharge, and at this time by measuring the amount of current flowing to obtain a vacuum degree from it. At this time, when the vacuum container is evacuated, the amount of ions per unit volume decreases inside the vacuum container. As the degree of vacuum increases, the amount of current flowing between the two electrodes decreases. Therefore, in order to measure the degree of vacuum precisely toward the high vacuum, a higher voltage must be applied to the electrode in the vacuum vessel, and the current flowing must be accurately measured. That is, for the vacuum measurement, the amount of voltage and current flowing in the vacuum vessel should be measured, and at the same time, the voltage value should be properly controlled.

An apparatus for measuring voltage and current and performing voltage control as described above is called an ion pump controller.

1 is a hardware configuration diagram showing the connection between the vacuum vessel and the ion pump controller, Figure 2 is a view showing the configuration of the electrode arrangement and the ion pump controller for the vacuum measurement inside the vacuum vessel.

The conventional ion pump controller for vacuum measurement is a very expensive equipment, and there are not many developers at home and abroad. In addition, different vacuum measuring devices have different measurement values for the same vacuum, and furthermore, accurate data for measuring the degree of vacuum are not disclosed.

Even in the case of the current ion pump controller developed in Korea, the principle of vacuum measurement is the same as the above description, but has a problem in terms of accuracy of vacuum measurement.

In addition, in case of ion container, the capacity of 30, 60, 90, 120, 180, 240, 480, 600 liters, etc. is different. If you measure it, you will not get the correct value.

In addition, the vacuum measurement usually requires more than two channels, but in this case, two 1-channel ion pump controllers may be used, but the cost is high.

In addition, the data transfer between two microprocessors, which are in charge of the calculation and output part of the conventional 1-channel ion pump controller, uses an interrupt-based 1-bit serial communication method. There was also a problem that the phenomenon occurs.

The present invention has been made to solve the above problems, can be applied at the same time according to the characteristics of the ion container of various capacities, and also can measure and display the high-pressure control and vacuum degree of two channels or more simultaneously in software. Reduces product costs by designing systems based on low-cost microprocessors, stores capacity-specific lookup tables based on existing advanced product results, and dualizes communication between two microprocessors responsible for computation and output The purpose of the present invention is to provide a multi-capacity 2-channel ion pump controller for improving overall system stability by using a dual port memory and a vacuum measuring method using the same.

1 is a hardware configuration diagram illustrating a connection between a vacuum vessel and an ion pump controller.

2 is a view showing the configuration of the electrode arrangement and the ion pump controller in the container for vacuum measurement inside the vacuum vessel.

3 is a flowchart of a procedure of calculating a degree of vacuum after a current value is calculated and calculated using a lookup table after amplification and voltage conversion.

4 is an exemplary diagram of a three-dimensional lookup table showing a degree of vacuum corresponding to an ADC value for each capacity.

FIG. 5 is a graph for explaining a method of calculating the degree of vacuum from lookup table data for an arbitrary capacity.

FIG. 6 is a diagram illustrating a vacuum ion pump controller for designing the vacuum degree measurement part and the result display part, and for explaining the communication contents between the processors through the dual port memory.

<Description of main parts of drawing>

10: vacuum container

50: ion pump controller

60, 70: microprocessor

61: vacuum controller (high voltage switch)

62: high voltage generator

63: memory

64: current detector

65: amplification and voltage conversion means

66: ADC (Analog to Digital Converter)

67: 3D Look Up Table (LUT)

71: keyboard

72: vacuum degree display

80: dual port memory

The controller of the present invention to achieve the above technical problem

In the multi-capacity 2-channel ion pump controller,

A microprocessor 60 for calculation, a microprocessor for display 70, and a dual port memory 80 capable of inputting and outputting the microprocessor,

The calculation microprocessor 60 includes a high voltage switch 61 for controlling a high voltage generator 62 for generating a high voltage in the vacuum vessel 10, a memory 63, an EEPROM for storing parameters for each channel, and a vacuum. Configured to control the operation of the ADC 66 to digitize 66 the amplification and voltage conversion 65 of the current value sensed by the current detector 64 from the vessel 10,

The display microprocessor 70 is configured to receive a parameter from the keyboard 71 and output it to the display 72,

The input terminal including the current detector 64 is configured to have two modules designed in a modular form to enable two-channel input, multi-capacitance characterized in that configured to receive the analog current value for each channel using a multiplexer It is a corresponding two-channel ion pump controller.

On the other hand, the measuring method of the present invention

In the vacuum measuring method using a multi-capacity 2-channel ion pump controller,

A preparatory step of storing the ADC value of the current value and the vacuum value of the high precision equipment at the time in the form of a three-dimensional lookup table while changing the vacuum degree for each capacity of the vacuum container in advance;

A first channel selection step of selecting one channel through the multiplexer to measure an actual degree of vacuum;

A storage step of storing, by the display microprocessor, a parameter including the capacity of the vacuum vessel installed in the channel at a predetermined address of the dual port memory;

The computational microprocessor measures the current value of the channel, amplifies and converts it, digitizes it through the ADC, and reads a parameter including the capacity of the vacuum vessel from a predetermined address of the dual port memory. Retrieving a dimension lookup table;

A vacuum degree calculating step of finding a value (x1, x2) immediately before and immediately after the digital value (x) of the current, reading the corresponding vacuum degree values (y1, y2) and calculating the vacuum degree (y) by a proportional expression;

A display step in which a computing microprocessor stores the calculated degree of vacuum in a predetermined address of a dual port memory, and the display microprocessor reads the address and displays it on a display;

A second channel selection step of selecting another channel using the multiplexer;

Repeating the storing step, retrieving step, vacuum degree calculation step and display step again;

It is a vacuum measurement method using a multi-capacity two-channel ion pump controller, characterized in that consisting of.

That is, the present invention stores the vacuum degree calculated by the existing expensive equipment for each capacity of the ion container in the form of a three-dimensional lookup table with the analog-to-digital converter results of the hardware developed through the present invention, Based on that value, it is implemented to calculate the same result as expensive equipment. In addition, it is designed to operate 2 channels independently, and the measurement unit and the output unit are each configured by using a separate microprocessor to compensate for the insufficient microprocessor specification, and the system using a communication method through the dual port memory between processors The stability of the. In addition, the results calculated for each channel are implemented through the software process, and the independent result output function is implemented by passing the parameters for the two channels.

Hereinafter, the operation of the invention will be described.

Full flow chart

3 is an overall flow chart of the present invention. First, the current value is input, amplified, converted to voltage, and then digitized through ADC conversion. This value is converted into a vacuum value based on the data of the lookup table stored for each capacity and then outputs the result for each channel.

3D Look-Up Table

Existing foreign high-end equipment has high precision, but is very expensive, and a development product based on a relatively low specification microprocessor has a disadvantage of low precision. In addition, the existing developer does not disclose a variety of know-how related to the measurement of vacuum, there is a problem that can not guarantee the measurement accuracy when developing new products from other companies. In addition, the capacity of the vacuum vessel varies from 30 liters to 600 liters, for example, because the physical characteristics are different for each capacity, the vacuum control and measurement equipment is dedicated equipment. Therefore, the measuring equipment should preferably be capable of precise vacuum measurement through a simple setting for each capacity.

In order to solve this problem, the present invention selects the most accurate product among foreign products, and changes the vacuum degree from capacity of 30 liters to 600 liters for each capacity, and converts the current value and the vacuum value at that time into an analog-to-digital converter (ADC: Analog). After converting through Digital Converter, save the result. In this way, the degree of vacuum accuracy can be improved to the same performance as that of foreign luxury products.

4 shows an example of a three-dimensional lookup table showing a table of vacuum degrees corresponding to an ADC result obtained by reading a current value, which is an analog value measured for each capacity, and converting it into a digital value. 5 is a graph illustrating a method of calculating a vacuum degree from an ADC measurement value. Using the example of the lookup table of FIG. 4, when the ADC conversion value of the current value of the target to measure the current vacuum degree is 2,020, the vacuum degree may be calculated as follows.

Separate measurement and calculation units and dual port memory

The controller of the present invention is designed independently of the calculation unit and the output unit based on the 8-bit microprocessor, the ADC is converted to the current value to calculate the degree of vacuum based on this, and outputs the result through the liquid crystal display device.

In addition, the ion pump controller operates a switch that applies a high voltage to the inside of the vacuum chamber, and the degree of vacuum can be checked by a computer through serial communication.

Low-cost 8-bit microprocessors lack performance to do all of these things simultaneously. Therefore, in the present invention, two low-cost 8-bit microprocessors are used to separate the vacuum measurement part from the display and key input parts.

The processor of the display unit obtains the vacuum calculation value through communication between the processors and outputs it to the LCD, and changes the internal parameters through the keyboard input.

On the other hand, the system stability by using shared memory.

Conventional 1-channel ion pump controller is designed based on one microprocessor and one microprocessor. The data transfer between microprocessors is based on interrupt-based 1bit serial communication. Occasional downtime due to excessive communication load.

The calculation unit and the display unit can reduce the load of the entire system through indirect communication and can also ensure system stability. For this purpose, shared memory is used. In other words, dual-port memory is used to exchange data between two processors, increasing the stability of the entire system.

The microprocessor of the calculation unit uses the two-channel current input value, calculates the degree of vacuum by a software method using the parameters stored in the promised address of the shared memory, and writes the value to the promised address of the shared memory. The microprocessor of the display unit reads the promised address value of the shared memory and outputs it to the LCD screen.

On the other hand, in the case of modifying the parameters for each channel in the display unit, the modified contents are stored in the internal EEPROM and at the same time, the changed value is stored in the promised address of the shared memory. Then, the calculation unit checks the modified contents of the channel-specific parameters in the shared memory and uses them in the vacuum calculation.

Using the same method as described above, the microprocessor of the calculation unit and the display unit perform the necessary functions by writing or reading a value into the shared memory without forcing synchronization with each other, and thus do not have a load for serial communication between the microprocessors. As a result, the stability of the entire system is greatly improved.

2-channel simultaneous operation

On the other hand, in order to implement 2 channels, the existing calculation unit designed the existing 1 channel analog circuit part to 2 channels and designed the channel-by-channel selective operation using multiplex. Channel-specific operation results and various parameters are stored in dual-port memory for effective output.

The two-channel implementation has some changes compared to the existing one-channel in terms of hardware and software.

(1) hardware

The hardware input stage for 1-channel vacuum measurement is designed in the form of module. A maximum of two input stage hardware modules were used for two-channel vacuum measurement. In addition, the multiplex allows the analog current value of each channel to be digitized through a single ADC. The vacuum calculation part was designed using one microprocessor to minimize hardware configuration, and the vacuum calculation for each channel was implemented through software.

(2) software

Using a low cost microprocessor, two channels of vacuum can be measured simultaneously. At this time, the parameters that should be specified for each channel are stored in the EEPROM so that they cannot be deleted even if the power is turned off. And parameter setting for each channel can be easily modified through LCD window. In addition, through RS485 serial communication, the channel-specific parameters can be modified, and the degree of vacuum can be measured remotely.

When the power is supplied again after the power failure, the controller is operated in the state before the power failure.When the controller lid is opened while the power is supplied, a danger alarm sounds, a warning is displayed on the LCD window, and the high pressure is stopped. The safety is increased, and if over current exceeds the set value, a warning is displayed and the power is shut off.

The vacuum and other parameters of the two channels were set and stored or referenced in the memory map in EEPROM and Dual Port Memory.

In addition, various changes in the overall operation of the system are internalized so that they can be quickly delivered to users through LCDs, speakers, and LEDs. The parameters required for internal calculations are stored in the internal EEPROM so that if a power failure occurs and power is supplied again, it automatically returns to the state before the power failure. It also adds a function to prevent high voltage accidents that can occur in abnormal situations such as opening the lid while the power is on.

According to the present invention as described above before applying the high-pressure inside the vacuum vessel by volume before the measurement converts the current into a digital value and the degree of vacuum calculated by the foreign high-priced high-precision products with the ADC of the product developed in the present invention 3 After storing it in the form of a dimensional lookup table, the measurement was performed to measure the degree of vacuum based on the lookup table using the measured ADC value to enable high-precision measurement. It is possible to implement hardware with low cost 8-bit microprocessor by separating the part to change, and measure two channels at the same time, and improve stability by having to modify and check parameters through shared memory. That has a very breakthrough effect.

Claims (2)

In the multi-capacity 2-channel ion pump controller, A microprocessor 60 for calculation, a microprocessor for display 70, and a dual port memory 80 capable of inputting and outputting the microprocessor, The calculation microprocessor 60 includes a high voltage switch 61 for controlling a high voltage generator 62 for generating a high voltage in the vacuum vessel 10, a memory 63, an EEPROM for storing parameters for each channel, and a vacuum. Configured to control the operation of the ADC 66 to digitize 66 the amplification and voltage conversion 65 of the current value sensed by the current detector 64 from the vessel 10, The display microprocessor 70 is configured to receive a parameter from the keyboard 71 and output it to the display 72, The input terminal including the current detector 64 is configured to have two modules designed in a modular form to enable two-channel input, multi-capacitance characterized in that configured to receive the analog current value for each channel using a multiplexer 2-channel ion pump controller. In the vacuum measuring method using a multi-capacity 2-channel ion pump controller, A preparatory step of storing the ADC value of the current value and the vacuum value of the high precision equipment at the time in the form of a three-dimensional lookup table while changing the vacuum degree for each capacity of the vacuum container in advance; A first channel selection step of selecting one channel through the multiplexer to measure an actual degree of vacuum; A storage step of storing, by the display microprocessor, a parameter including the capacity of the vacuum vessel installed in the channel at a predetermined address of the dual port memory; The computational microprocessor measures the current value of the channel, amplifies and converts it, digitizes it through the ADC, and reads a parameter including the capacity of the vacuum vessel from a predetermined address of the dual port memory. Retrieving a dimension lookup table; A vacuum degree calculating step of finding a value (x1, x2) immediately before and immediately after the digital value (x) of the current, reading the corresponding vacuum degree values (y1, y2) and calculating the vacuum degree (y) by a proportional expression; A display step in which a computing microprocessor stores the calculated degree of vacuum in a predetermined address of a dual port memory, and the display microprocessor reads the address and displays it on a display; A second channel selection step of selecting another channel using the multiplexer; Repeating the storing step, retrieving step, vacuum degree calculation step and display step again; Vacuum degree measurement method using a multi-capacity 2-channel ion pump controller, characterized in that consisting of.