Abstract:
A radiation test system that couples with a radiation test field and a radiation controller. The radiation controller records the flow of radiation particles and the test results obtained from a test component. The radiation controller also controls a radiation particle accelerator so that the test component is irradiated with a cyclically varying radiation beam. The radiation test system further includes a daughter board, a motherboard, a power source, a near-end monitor and a far-end monitor. The near-end monitor is responsible for initiating a test program to test the test program, monitoring the test status and recording the test data. The far-end monitor remotely controls the near-end monitor to initiate an irradiation testing of the test component. The far-end monitor also receives test data submitted by the near-end monitor so that test results may be further analyzed.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of Invention 
     The present invention relates to a radiation test system. More particularly, the present invention relates to a radiation system having a set of testing steps capable of reducing setup time and facilitating operation. 
     2. Description of Related Art 
     In aerospace industry, electronic components are often sent to outer spacer for a particular mission. Since these components may be bombarded by intense radiation in outer space for long periods, stringent radiation checks are required. For example, components used on satellites have to undergo intensive radiation testing. Those failing the radiation test are immediately discarded. For those that pass the radiation test, only the best component is selected. 
     The setup and maintenance of a radiation test field is expensive. Due to special shielding regulations, facilities within the testing field may not be modified at will. Most often than not, a test is carried out using original equipment within the testing field. Components to be tested are usually placed inside the radiation field connected to a nearby computer. All testing is controlled at a remote site through keyboards and monitors connected to the in-field computer by extension cables. In general, different test components may require different control interface and hence a different setup. 
     To protect people against hazardous radiation, personnel involved in radiation testing must be confined to the remote control center. Should any problem occur inside the radiation field, error rectification has to be delay until radiation has died down. However, testing time within a radiation test field is usually limited. For example, if three components each requiring 7 hours of continuous testing need to be tested in a day, actual time remaining for error detection and wire changing is minimal. In addition, the cost of operating a radiation test field is astronomical. Hence, slight increase in operational time may entail a huge monetary waste. 
     SUMMARY OF THE INVENTION 
     Accordingly, one object of the present invention is to provide a radiation test system having a set of testing steps capable of reducing setup time and facilitating operation. 
     To achieve these and other advantages and in accordance with the purpose of the invention, as embodied and broadly described herein, the invention provides a radiation test system. The radiation test system is coupled to a radiation test field and a radiation controller. The radiation controller records flow of radiation particles and test results of a test component. The radiation controller also controls a radiation particle accelerator so that the test component is irradiated with a cyclically varying radiation beam. The radiation test system further includes a daughter board, a motherboard, a power source, a near-end monitor and a far-end monitor. The daughter board holds and makes electrical connections with the test component. The motherboard is coupled to the radiation controller. The motherboard houses and makes electrical connections with the daughter board. The power source provides necessary electrical power to the motherboard and the test component. The near-end monitor is connected to the motherboard via a short transmission cable. The far-end monitor is connected to the near-end monitor through a long transmission cable. 
     The radiation controller transmits irradiation signals to the motherboard and informs the motherboard about the irradiation period. The motherboard transmits error signals resulting from an overload current in the test component to the radiation controller and informs the radiation controller to stop radiation count. Bi-directional transmission between the motherboard and the radiation controller is achieved through an RS-232 interface. The near-end monitor triggers a testing program driving the motherboard such that current testing state is monitored and testing data are recorded. During a continuous irradiation cycle, the motherboard also transmits test data produced by the test components to the near-end monitor. The far-end monitor is capable of remotely controlling the near-end monitor so that irradiation test on the test component can be executed. Furthermore, the far-end monitor is capable of receiving test data submitted by the near-end monitor so that post-irradiation status of the test component can be gauged. 
     This invention also provides an alternative radiation test system. The radiation test system is coupled to a radiation test field and a radiation controller. The radiation controller records the flow of radiation particles and test results of a test component. The radiation controller also controls a radiation particle accelerator to produce a cyclically varying irradiation on the test component. The radiation test system further includes a daughter board, a transmission cable connector, a digital signal processor, a data buffer, a first address &amp; control buffer, a decoder &amp; universal asynchronous transceiver circuit, a power protection circuit &amp; data latch, a second address &amp; control buffer, a control buffer, a power supply, a near-end monitor and a far-end monitor. 
     The daughter board holds and makes electrical connections with the test component. The transmission cable connector is a connector with a short transmission cable. The digital signal processor is coupled to the transmission cable connector and driven by a test program to produce a test pattern. Test data produced by the test component is transmitted by the transmission cable connector. The data buffer is a data bus for isolating the digital signal processor and the daughter board. The data buffer also provides data bus signals for driving the digital signal processor. The first address &amp; control buffer is an address and control signal bus for isolating the digital signal processor and the daughter board. The decoder &amp; universal asynchronous transceiver circuit decodes data from the data bus signal so that control signals for controlling the test component is generated. The decoder &amp; universal asynchronous transceiver circuit also receives irradiation signals produced by the radiation controller and outputs an error signal due to an overload current in the test component to the radiation controller. A bi-directional transmission of commands and test results is achieved via an RS-232 interface. The power protection circuit &amp; data latch is coupled to the decoder &amp; universal asynchronous transceiver circuit for providing power to the test component. When current load occurs in the test component, power to the test component is cut and a current overload signal is transmitted to the digital signal processor. In the meantime, data signals from the digital signal processor are latched so that necessary preset signals, reset signals, power-triggering signals and error signals are provided. The second address &amp; control buffer is able to providing necessary signal to the digital signal processor for driving the decoder/general-purpose asynchronous transceiver circuit. The control buffer picks up control signals from the decoder &amp; universal asynchronous transceiver circuit and transmits the signals to the daughter board. The power supplier provides power to various modules and the test component in the radiation test system. The near-end monitor is connected to the transmission cable connector via a short electrical cable. The near-end monitor is responsible for triggering and terminating test programs as well as monitoring and recording test status and test data of the test component. The far-end monitor is connected to the near-end monitor through a long electrical cable. The far-end monitor not only receives test status and data from the test component, but also controls the near-end monitor to initiate radiation test. 
     It is to be understood that both the foregoing general description and the following detailed description are exemplary, and are intended to provide further explanation of the invention as claimed. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The accompanying drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention. In the drawings, 
     FIG. 1 is a schematic showing components and interconnections of a radiation test system according to one preferred embodiment of this invention; and 
     FIG. 2 is a block diagram showing a motherboard system for the radiation test system according to this invention. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Reference will now be made in detail to the present preferred embodiments of the invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers are used in the drawings and the description to refer to the same or like parts. 
     FIG. 1 is a schematic showing components and interconnections of a radiation test system according to one preferred embodiment of this invention. As shown in FIG. 1, a radiation controller  106  is placed inside a control room  102  of a radiation test field. The radiation controller  106  records the flow of radiation particles and the test results of a test component (the test component can be a SDRAM, a Flash ROM, a CPLD or a Watch-dog Timer, for example). The radiation controller  106  also controls the generation of radiation particles by an accelerator (not shown) so that the test component is irradiated with cyclically varying radiation. 
     The test component (not shown) is plugged into the socket on a replaceable daughter board  108 . The daughter board  108  has connecting pins that can be reset to produce the test signals required by the test component. The daughter board  108  is also capable of testing two functionally identical test components (not shown) at the same time. During testing, only the test component (not shown) and the daughter board  108  are subjected to irradiation. 
     A motherboard  110  is coupled to the radiation controller  106 . The daughter board  108  and the motherboard  110  are electrically connected. A power supplier  112  provides necessary power (a 5V or a 3.3V) to the motherboard  110  and the test component (not shown). A computer  114  is connected to the motherboard  110  through a J-Tag transmission cable connector. Through an Ethernet transmission cable, the computer  116  may hook up with another computer  114 . 
     The radiation controller  106  transmits irradiation signals (radiation beam on/off signals) to the motherboard  110  to inform the motherboard  110  about the radiation status. Should current overload occurs while the test component (not shown) is undergoing a testing, the motherboard  110  will transmit a veto signal to the radiation controller  106  informing the controller  106  to terminate the radiation count. As soon as all test equipment is ready, the radiation controller  106  and the motherboard  110  communicate with each other through an RS-232 interface. To begin the testing, an INIT command is issued from the radiation controller  106  inside the control room  102  to the motherboard  110 . On receiving the initiation signal, the motherboard  110  transmits a group of test data to the computer  114  after each irradiation cycle (each cycle includes a radiation-off and a radiation-on). After the completion of several tens of irradiation cycles, the testing operation is temporarily suspended by the motherboard  110  and the test data is stored inside the computer  114 . Thereafter, the irradiation strength, angle or radiation type is changed before the testing operation is continued. 
     The computer  114  uses triggered testing programs to drive the motherboard  110  so that the test component is activated, status of the test component is monitored and the resulting test data is recorded. During the testing operation, the computer  116  also receives test data from the computer  114  through an Ethernet transmission cable so that radiation test status of the test component (not shown) is monitored. Should the computer  116  discover any abnormality of the test component (not shown), the computer  116  may signal to the computer  114  so that the radiation testing is immediately halted. 
     FIG. 2 is a block diagram showing a motherboard system for the radiation test system according to this invention. As shown in FIG. 2, the motherboard  200  includes a JTAG connector  202 , a digital signal processor  204 , a data bus  206 , a data buffer  208 , a data bus  212 , a decoder &amp; universal asynchronous transceiver circuit  214 , a power protection circuit &amp; data latch  216 , a data bus  218 , an address &amp; control buffer  220 , an address &amp; control signal bus  222 , an address &amp; control signal bus  224 , a RS-232 interface, an address &amp; control buffer  226 , a control buffer  228 , an address &amp; control signal bus  230 , a bus  232  and another bus  234 . 
     The JTAG connector  202  on the motherboard  200  is a J-tag transmission cable connector. The digital data processor  204  is connected to the JTAG connector  202  and the JTAG connector  202  is in turn connected to a near-end computer  114  (refer to FIG.  1 ). The digital signal processor  204  is driven by a test program submitted by the near-end computer  114 . The digital signal processor  204  not only provides a test pattern to the data bus  206 , but also reads test data from the data bus  206  and transmits the data back to the computer  114  (refer to FIG.  1 ). 
     The data buffer  208  isolates the data bus  206  and the data bus  212  between the digital signal processor  204  from the daughter board  210 . Hence, normal operation of the digital signal processor  204  is safeguarded against the effect of any current overload in the test component (not shown). The data buffer  208  also provides data to the data bus  218 . Signals sent to the data bus  218  drives the digital signal processor, the decoder &amp; universal asynchronous transceiver circuit  214  and the power protection circuit &amp; data latch  216 . The address &amp; control buffer  220  isolates the address &amp; control signal bus  222  and the address &amp; control signal bus  224  between the digital signal processor  204  and the daughter board  210 . Similarly, this is to safeguard the digital signal processor  204  against any effect due to current overload in the test component (not shown). 
     The decoder &amp; universal asynchronous transceiver circuit  214  decodes signals on the data bus  218  so that signals necessary for controlling the test component (not shown) is produced. Through the RS-232 interface, instructions and test results shuttle between the transceiver circuit  214  and a radiation controller (not shown). Furthermore, radiation test signals (radiation on/off) and veto signals also shuttle between the transceiver circuit  214  and the radiation controller via signal lines (not shown). 
     The decoder &amp; universal asynchronous transceiver circuit  214  may also include an asynchronous transceiver control circuit (not shown). The asynchronous transceiver control circuit (not shown) may further include random generator modules, serial-to-parallel receiving modules, parallel-to-serial receiving modules, receiving and transmitting status and output modules, odd-even generator &amp; detection modules and interface control module (all the modules not shown). Signals or data are transmitted according to their respective functions of the modules. 
     The power protection circuit &amp; data latch  216  is coupled to the decoder &amp; universal asynchronous transceiver circuit  214  for providing power to the testing component (not shown). Should current overload occur in the test component, the power protection &amp; data latch  216  will cut off power to the test component and send a current overload signal to the digital signal processor  204  via the data buses  218  and  206 . In the meantime, data signals sent from the digital signal processor  204  is arrested serving as subsequent set-reset signals, power-triggering signals and veto signals for the power protection circuit &amp; data latch  216 . Hence, the power protection circuit &amp; data latch  216  can be set or reset so that power is supplied to the test component again. 
     The address &amp; control buffer  226  provides signals from the digital signal processor  204  to the decoder &amp; universal asynchronous transceiver circuit  214  via the address and control signal bus  230 . The control buffer  228  receives decoded control signals from the decoder &amp; universal asynchronous transceiver circuit  214  and retransmits the signals to the daughter board  210 . The control buffer  228  isolates the buses  232  and  234  between the decoder &amp; universal asynchronous transceiver circuit  214  and the daughter board  210 . Hence, normal operation of the decoder &amp; universal asynchronous transceiver circuit  214  is safeguarded against the effect of any current overload in the test component (not shown). 
     In conclusion, one major advantage of using the general-purpose testing board to test different components is that independent design of the testing board is not required. By changing the testing steps, local on-site pre-simulation can be conducted. Hence, time required to set up an actual testing field is greatly reduced. Ultimately, an easy to maintain and operate radiation test system capable of on-line monitoring of test component is produced. 
     It will be apparent to those skilled in the art that various modifications and variations can be made to the structure of the present invention without departing from the scope or spirit of the invention. In view of the foregoing, it is intended that the present invention cover modifications and variations of this invention provided they fall within the scope of the following claims and their equivalents.