반도체 이온 센서용 원격 측정 시스템 개발

국문 초록 (Abstract)

집적회로 제조공정 기술을 활용하여 제조되는 FET형 바이오/이온 센서는 고감도화, 초소형화, 규격화 및 대량생산에서 얻어지는 경제성 등의 잇점 때문에 의료분야, 산업분야 및 환경관리분야 등에서 많은 응용이 기대되고 있다. 본 연구에서는 ISFET의 출력신호를 원거리에서도 수신할 수 있는 경제적인 전용 디지털 데이터 전송시스템을 구현하므로써 센서의 실제적 응용을 가능케하고 측정된 데이터의 효율적 처리 및 관리를 도모할 수 있게 하였다. 개발된 원격측정장치는 전송을 위한 채널을 송신 및 수신측에서 임의로 입력시킬 수 있으며, 측정 및 송신과 동시에 수신측 터미널의 화면에 개별적 센서신호의 변화가 실시간으로 표시되고 각 채널의 데이터 파일은 생성 후 저장된다. 송신 및 수신측에서 측정채널의 변경입력이 가능하고 또한 수신측터미널에서는 전송회로의 측정이득을 4단계로 제어할 수 있다. 전송속도는 16채널로 동시 전송시 16 sample/sec/channel이고 전송분해능은 샘플당 12 bit이며 ISFET신호전송을 위한 2개의 온도보상 채널을 구비하고 있다.

다국어 초록 (Multilingual Abstract)

1. Title
Development of Remote Sensing System for FET Type Ion Sensors.
2. Object
The object of this project is to develope microprocessor based 16 channels remote sensing system for ISFET type sensors through public telephone line. This system can display the trend of sensor's output signal in real time mode at the monitor screen and provide useful base of efficient data archiving and management using personal computer.
3. Contents of the study
1) Study on the conditioning, multiplexing and A/D conversion of multiple ISFET sensor signal.
2) Finding the interfacing method between microprocessor controller circuit board and communication modem.
3) Study on the communication protocol and its related electronic circuit to control the transmission parameter such as channel number and gain.
4) Study on the data receiving, saving and real time graphic displaying method at the receiver terminal.
4. Scope and methods
1) The folio wings are specification and performance of the developed remote sensing system.
(A) Transmission system
- Control processor : Intel 8751
- Analog inputs : 16 cannels
- Preamplifier : 14 channels, Null balanced type, opto-isolation
- Temparature compensation channel : 2 channels(15, 16 ch)
- A to D converter : 12 bits
- Sampling rate per channel : 15 samples/channel
- Processor-modem interface : UART ( 2400bps )
- Transmission methid of applied modem : Full duplex
- Baud rate of communication : 2400 bps
- Measurement gain selection step : X1, X2, X3, X8
- Input method of tel. no. and gain : 12 Numeric key
- Power supply : Switching type, 100V 60㎐
- Dimension of transmitter : 33 ㎝(W) × 16 ㎝(H) × 43 ㎝(L)
(B) Receiving PC system
- Main processor : 80486
- Base memory : 640 kbyte or more
- Hard disk driver : 120 Mbyte
- Floppy disk driver : 1.44 Mbyte 3.5", 1.2 Mbyte 5.25"
- Equipped modem : Full duplex (2400 BPS)
- Modem to PC interface : RS-232C serial port
- Video display board : SVGA
(C) Communication software for remote sensing
- Real time displaying and automatic data saving of the 16 chammels.
- Channel and gain selection functions are offered.
- Menu driven methids are employed in display design.
- In both sides, initiation and termination of the telemetric communication for telemetry is prossible.
2) Method of study
For the efficient development, studies are divided into 4 parts. The first consist of preamplifier, multiplexer and A/A converter, and the second is the main control circuit based on microprocessor. The third and forth consist of transmitter control software and receiver software respectively. Each part is developed arranged as the following procedure : (1) approximating layout, (2) its detailed design, (3) its application test and the modification for improvement.