KR900007123B1 - Data aquisition system using ibm-pc - Google Patents

Abstract

The system being usable at the IBM-PC compatible computer comprises; a parallel interface (PPI) having A, B, C and D port receiving digital conversion data and providing A/D converter (ADC) start signal on ADC channel selection signal, and converted digital data; an A/D converter (ADC) started with B port signal of the PPI applying the digital data converted from analog signal of sensor and interface circuit to A port of the PPI, and providing an interrupt signal (IRQ2) to I/O slot (IOS) through a terminal (EOC) after completing the data conversion; a counter/timer (CTC) counting the speed check input pulse applied to selected channel (INO) to provide the accessed data to host computer at every sampling period; and an address decoder logic (ADC) applying a chip selecting signal to the CTC and PPI.

Description

Data Acquisition System Using IBM-PC

1 is a circuit diagram of the present invention.

2 is a flowchart of the present invention and an interrupt service routine.

* Explanation of symbols for main parts of the drawings

Bl, B2: Buffer PPI: Parallel Interface

ADC: Analog Digital Converter CTC: Counter / Timer

ADL: address decoder logic IOS: I / O slot

The present invention relates to a general-purpose data acquisition system, and more particularly, to a system for continuously detecting, storing and analyzing desired data using an IBM-PC and a compatible model thereof.

In general, it is best to use a dedicated data acquisition system in conjunction with dedicated measurement equipment to detect continuous data. Dedicated data acquisition system is equipped with independent microprocessor, analog digital converter, timer and input / output port element, control them internally, and store data collected by RAM or floppy disk driver for continuous data storage. It is a system.

However, the dedicated data acquisition system as described above has various advantages such as convenience, high speed processing, and scalability of the data channel. However, there are the following problems.

In other words, the data storage method has a unique data file structure, and the medium for storing the data is different from the commonly used data medium for IBM-PC (for example, 2DD floppy disk). Since there is no method of up loading or uploading through a separate built-in RS-232C port, time is delayed in analyzing and processing the collected data and it is a dedicated system. No change was possible. In addition, the biggest disadvantage of the dedicated data acquisition system is that it is very expensive in terms of cost, and a large amount of investment is required for the use of dedicated equipment.

The present invention has been made to solve all the problems of the dedicated data aquajisin system as described above, and the continuous data detection and storage using the most widely used general purpose computer, IBM-PC or its luxury model and Its purpose is to provide a general purpose data acquisition system that enables analysis.

In order to achieve the above object, in the system of the present invention, a digital and analog input / output card is connected to an internal input / output slot of an IBM-PC, interfaced with measurement data, and control of these cards is performed by the IBM-PC. Collect and store the collected data for immediate use as a data file for analysis and processing software.

Hereinafter, an embodiment of the present invention will be described as an example of data detection such as acceleration / deceleration speed of a print and temperature change of a head in a printer.

In order to develop a printer, it is necessary to continuously store and analyze data in which data must be obtained continuously, that is, acceleration and deceleration speed, head temperature change, and line feed speed data.

Acceleration and deceleration velocity measurement is mainly done using digital tachometer. Digital ride meter uses instantaneous speed. Digital ride meter displays instantaneous speed as a digital value. In case it is not suitable.

In addition, the temperature measurement of the head uses a thermometer, but the thermometer is not suitable because the experimenter has to read the scale one by one, and when the digital thermometer is used, only the instantaneous value of the temperature is displayed and no continuous data is obtained.

Therefore, when continuous data such as acceleration / deceleration speed measurement and head temperature measurement of the above factors are required, it is best to use a dedicated measurement equipment and a dedicated data acquisition system by connecting them. You have a problem.

Hereinafter, a case in which temperature and velocity measurements are performed by applying the present system as shown in the circuit diagram of FIG. 1 will be described.

Referring to the configuration of the present invention with reference to Figure 1, the buffers (B1, B2) connected from the input and output slots (IOS) of the IBM-PC to buffer the data bus and the address bus, respectively, the parallel interface (PPI) The data exchanges data with an analog digital converter (ADC) connected to the sensor and the interface circuit, and the analog digital converter (ADC) converts a signal applied from the sensor and the interface circuit into a digital signal.

In addition, the counter / timer (CTC) counts the pulses input according to the speed, and the address decoder logic (ADL) decodes the address through the buffer B1 to the parallel interface (PPI) and the counter / timer (CTC). The chip select signal CS is applied. On the other hand, the clock generator provides a reference clock signal to the analog digital converter (ADC) and the counter / timer (CTC).

The circuit of the present invention having the above-described configuration is controlled by software such as the flowchart of FIG. 2, and the operation thereof will be described by dividing the temperature measurement time and the speed measurement time.

(1) At the time of temperature measurement

When the control program is loaded and started to run in the command standby state of the IBM-PC, the user is asked whether to select between temperature data and velocity data in step 10, and when the temperature is selected, the data file name is asked in steps 100 to 102. You will be asked to enter a file, ask for a sampling cycle, save the sampling cycle according to the input sampling cycle, and open the data file with the name above.

Then, in step 103, a signal is applied from the host computer (IBM-PC) to initialize each device so as to fit the storage of temperature data. Accordingly, a parallel interface (PPI), an analog digital converter (ADC), and a counter / timer (CTC) are applied. ) Is initialized.

The address output from the input / output slot IOS is sufficiently amplified by the buffer B2, and the data signals are amplified by the buffer B1. The address decoder logic (ADL) determines the address of the parallel interface (PPI) or counter / timer (CTC) and applies a high signal to the chip select terminal (CS) of the parallel interface (PPI) or counter / timer (CTC). The corresponding element is selected, and the central processing unit (CPU) of the host computer controls the input / output of each chip by the address.

That is, a signal for selecting a control register inside the parallel interface is applied from the host computer to initialize the parallel interface (PPI), and the data of the A port is used as the input port, and the B and C ports are used as the output port. Initialize the parallel interface by authorization. In addition, the counter / timer (CTC) is initialized by receiving a signal indicating that the counter mode is used from the host computer, and the analog digital converter (ADC) selects an analog signal input channel to which a temperature sensor is connected. Initialize by applying the selection signal to the channel select port through the C port.

After initializing the device as described above, according to step 104, the host computer outputs a signal for accessing the analog digital converter ADC to the parallel interface PPI for inputting an analog signal of temperature.

At this time, the parallel interface PPI has ports A, B, C, and D, and these ports have different addresses by A2-A15 among the address signals A0-A15 output from the buffer B2. The four ports are selected by A0 and A1 of the address signals A0-A15. The A port is used to read the result data of the analog digital converter (ADC), and the B port is used to start the analog digital converter (ADC). The B0 bit is used, and the C0-C2 bits of port C are used to decode the channel of the analog digital converter (ADC).

Therefore, the above-described processes (sten 104 and 105) of outputting the read signal to the parallel interface PPI will be described in detail. In order to select the analog channel to which the temperature sensor is connected through the C port of the parallel interface (PPI), the address of the C port is applied to the parallel interface (PPI) via the address bus from the host computer, When the input channel selection data of the digital converter ADC is applied, the parallel interface PPI outputs the corresponding input channel data to the channel select terminal of the analog digital converter ADC through the C port.

The analog voltage input from the temperature sensor connected to the selected channel INO is started by applying the high level signal to the start terminal of the analog digital converter ADC with the B0 bit of the port B of the parallel interface PPI in accordance with step 106. To convert to a digital signal. At this time, after the analog digital converter (ADC) is started, the B0 of the parallel interface (PPI) is set to a low level so that start commands are no longer duplicated.

When the conversion is completed, the analog digital converter (ADC) changes the end of conversion (EOC) signal from the low level to the high level and applies it to the interrupt request signal terminal IRQ2 of the I / O slot IOS. This will request an interrupt from the central processing unit of the host computer.

Therefore, the CPU receiving the interrupt request jumps to the analog digital converter intercept service routine (step 20) according to the interrupt vector table to perform the interrupt service. In the interrupt service routine (step 20), the port A of the parallel interface (PPI) is accessed in accordance with step 21 to read the result data D0-D7 of the analog digital converter ADC. Temporarily save in the RAM area of the host computer. The data temporarily stored in the RAM area of the host computer is stored as one data in an initially opened data file, and simultaneously outputs the stored data to the screen (steps 23 and 24).

In this way, when the interpret routine is completed, the internal timer of the host computer is compared with the input sampling period according to steps 107 and 108, and when the user inputs a feature key to notify the end of the program or when there is no free area in the disk, the main routine The data file is completed by closing the file and terminating the program.

With the above operation, the access signal of the analog digital converter (ADC) is output to the parallel interface (PPI) by the command of the host computer at every sampling period. Accordingly, the above-described interrupt service routine is executed at every sampling period to continuously perform temperature data. The value can be saved, and the operation is terminated when a specific key is input or when there is no free space on the disk, so a data file can be created with the digital input of the temperature sensor.

(2) At the speed measurement

In the speed measurement, the speed is selected in step 10, and the data file name and sampling period are input in accordance with steps 200 to 202 and the data file is opened in the same manner as in the temperature measurement.

Next, in step 203, the counter / timer CTC is initialized to select the counter mode to obtain the number of pulses.

In the same operation as in the temperature measurement, the address signal of A2-A15 generates the chip select signal of the counter / timer CTC through the address decoder logic ADL, and the address signals A0-A1 are the counter / timer CTC. Select one of the channel and register. In initialization, the counter / timer (CTC) is initialized by selecting the control register to select channel 0 of the counter / timer (CTC) and outputting a signal through the data bus that sets the mode of this channel to the counter mode. At this time, the reference pulse of the counter mode is applied from the clock generator of FIG.

The host computer continuously accesses the counter / timer (CTC) according to the sampling period, and the counter / timer (CTC) is generated according to the speed and counts the input pulses.

Velocity data to be measured is externally supplied as an input pulse for speed check to the channel 0 input terminal (INO) of the counter / timer (CTC) through an encoder, etc. Since the counter value of is increased by one section, if the counted value is read every fixed sampling period, the sampling period is constant, so that data corresponding to the speed can be obtained according to the change of the counted value.

That is, by accessing the counter / timer (CTC) at regular intervals, the desired speed can be obtained by knowing the number of counted pulses.

Accordingly, as described above, channel 0 of the counter CTC is selected, and the counter CTC causes the read signal to amplify by applying the data of channel 0 to the buffer B1 through the data bus and then amplifying the buffer B1 to the central processing unit of the host computer. (Step 204). The data accessed in this way is temporarily stored in the RAM according to the steps 205, 206, and 207, and also stored in the turned off data file, and output to the screen.

Repeating the above process every sampling period, if a feature key is input or there is no free area on the disk, the file is closed and the program ends (steps 208 and 209).

As described above, the temperature measurement and the speed measurement according to the embodiment of the present invention have been described. In the above-described embodiment, by connecting the interface circuit and various sensors such as a pressure sensor or a humidity sensor to the remaining analog input channel of the analog digital converter (ADC), it is possible to configure a general data aquisin system.

As described above, according to the system of the present invention, a data acquisition system can be configured at low cost by using a board end connection to an input / output slot of a widely-used IBM-PC without using a dedicated data acquisition system. In addition, the data upload system can be uploaded to a computer by creating a data file that conforms to the IBM-PC format so that data analysis can be performed using the widely available utility software of IBM-PC. Therefore, it is possible to perform data processing quickly, and it is possible to freely change the hardware, connect various sensors according to the circuit deformation of the board, and have various advantages such as easy expansion and repair.

Claims (1)

One of four internal ports is selected by the address signals A0-A1 applied through the buffer B2 at the input / output slot (IOS) of the IBM-PC, and the digital converter data of the analog digital converter (ADC) is input to the A port. Outputs the start signal of the analog digital converter (ADC) with the B0 bit of port B, outputs the channel selection signal of the analog digital converter (ADC) with the C0-C2 bit of the C port, and outputs the analog digital converter (ADC) with the D port. A parallel interface (PPI) for applying the converted digital data to the host computer via a data bus, and an analog signal that is started by the B port signal of the parallel interface (PPI) and applied to a channel selected from a sensor and an interface circuit. Is converted into digital data and applied to the A port of the parallel interface (PPI), and the interrupt is interrupted to the input / output slot (IOS) through the terminal (EOC) at the end of conversion. The speed is applied to the selected channel 0 (INO) by selecting a channel by the address signals A0-A1 in synchronization with the clock signal applied from the clock generator and the analog digital converter ADC outputting the signal IRQ2. A counter / timer (CTC) that counts input pulses and outputs the accessed data to a host computer via a data bus at predetermined sampling periods, and decodes the address signals A2-A15 through the buffer B2 to counter / timer (CTC). And an address decoder logic (ADL) for applying a chip select signal to a parallel interface (PPI).

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