JPH0559368B2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention is applicable to recorders that digitize analog inputs such as current and voltage, sample them at high speed, and display them as dots on a display screen. Concerning what can be displayed and observed.

Conventional technology Conventionally, high-speed sampling recorders sample analog input data at intervals of, for example, 1 msec using an A-D converter, create dot data from the input data, and output it to a printer with a dot matrix configuration in almost real time. Waveforms and the like are printed as dots on the recording paper, or output to a display having a dot matrix configuration, and the waveforms and the like are displayed on the screen as dots. At this time, there are methods that show the sampling points of analog input data as dots on recording paper or a screen, and methods that interpolate between the points and show them as lines. Both sample at high speed, making it possible to create a recorder with good responsiveness.

Problems to be Solved by the Invention However, many of these recorders do not store previous waveforms, and therefore cannot observe the same waveform again except for the portion that remains on the display screen. Furthermore, even if the previous waveform is stored, the memory capacity is limited. For this reason,
Even with high-speed sampling recorders, one sample is
With the normal method of storing data in words in memory, waveforms can be recorded for a long time by slowing down the speed at which the recording paper is fed, but the waveforms are only stored for a fraction of the length of the paper. For example, if the sampling period is 1meec and the memory capacity is 64K words, the storage time will be approximately 65 seconds, so if the paper feed range is 1DIV/min, the waveform can only be stored for 1DIV. In particular, when using a recorder with a display and observing waveforms only on the display screen without printing, it is inconvenient that you cannot see even the waveforms from a while ago.

The present invention has been made in view of these conventional problems, and it is an object of the present invention to provide a recorder that can display the previous screen again.

Means for Solving the Problems Means for achieving the above object will be explained below using FIG. 1 showing the present invention.

The input section of this recorder includes an A-D converter 10 for converting analog input data into digital input data, and an operation section 14 having screen return instruction means for returning to a previously displayed screen. The dot data is created from input data sampled in chronological order through a circular buffer memory 20 which has addresses assigned corresponding to the dot matrix screen of the display 24 and write and read addresses cyclically configured. , a dot data input means 38 that repeats writing by changing the address of the circular buffer memory 20 every fixed sampling number or fixed time; and a dot data input means 38 which sets the read address at an address after the write address and repeats reading from the circular buffer memory 20 by changing the address. ,
A dot data output means 40 displays dot data on the screen of the display 24, and a return screen output means 42 returns the addresses from the circular buffer memory 20 in reverse chronological order by operating the screen return instruction means.
The output section is equipped with a display 24 for displaying a screen composed of dot matrix.

Effect The above means works as follows.

Analog input data coming from channel is A-
A D converter 10 converts digital input data. In this way, the dot data input means 38 creates dot data from the input data sampled in time series, and repeats writing by changing the address of the circular buffer memory 20 every fixed sampling number or fixed time. In addition, the circulation buffer memory 20
Addresses corresponding to the dot matrix screen of the display 24 are assigned to the memory, and write and read addresses are configured cyclically. The dot data output means 40 sets the read address from the circular buffer memory 20 at an address after the write address, changes the address, repeats reading, and displays the dot data on the screen of the display 24. Further, the return screen output means 42 returns the addresses from the circular buffer memory 20 in reverse chronological order by operating the screen return instruction means. Therefore, the previously displayed screen is displayed again. The display 24 displays a screen composed of dot matrix.

Embodiments Hereinafter, embodiments of the present invention will be described based on the accompanying drawings.

FIG. 2 is a block diagram showing the configuration of a recorder to which the present invention is applied. In the figure, 10, 12, 14 are A-D converters, timers, and
This is the operation section. This A-D converter 10 has, for example, 8
It has a bit configuration and converts analog input data such as current, voltage, and power input from the channel 16 into digital input data. At this time, the timer 12 generates an interrupt signal every 1 msec, for example, to start an interrupt routine in order to sample input data from the A/D converter 10. Also, the operation section 1
4 includes a start switch to start displaying the screen, a stop switch to stop displaying the screen, a backward screen return switch to return the display to the previous screen, and a forward screen return switch to return the display from that screen to the previous screen. etc., and each key to operate them is provided. The input data sampled in chronological order in this manner enters a device 18 equipped with a CPU, where dot data is created from the input data, and processing necessary for printing and screen display, such as writing it into memory, is performed. this
The device 18 equipped with a CPU includes a circular buffer memory such as a RAM 20 dedicated to storing dot data, a printer such as a dot printer 22 that prints the dot data read from the buffer memory 20, and a display such as a CRT to display the dot data. Displays 24 and the like are connected respectively.

For example, the device 18 equipped with the above-mentioned CPU includes
CPU (central processing unit) 26, ROM (read-only memory) 28, RAM (read-writable memory) 30, input port 32, output port 34,
A microcomputer consisting of a bus line 36 and the like is used. The CPU 26 corresponds to the central brain part of a microcomputer, and executes overall control according to program instructions, performs arithmetic and logical operations, and temporarily stores the results. It also controls peripheral devices. The ROM 28 stores a control program for controlling the entire recorder, an input data processing program, and the like. Also, RAM3
0 stores data such as calculation results of the CPU 26.
The input port 32 has an A-D converter 10 and a timer 1.
2. The operating section 14 and the like are connected. In addition, the output port 34 has a printer 22 and a CRT display 2.
4th grade is connected. The bus line 36 includes an address bus line, a data bus line, a control bus line, etc. for connecting these, and is also connected to the RAM 20 dedicated to dot data storage. In addition,
This RAM 20 is allocated to the address space of the CPU 26.

The dot printer 22 is a dot matrix printer equipped with a line-type thermal recording head capable of printing by moving the recording paper one dot line at a time. This thermal recording head has 1
There are dot positions along the line from number 1 to number X, for example number 256, indicating the amount of input data. Therefore, the vertical axis corresponding to 256 dots on the recording paper is the voltage axis, and the horizontal axis corresponding to the paper feeding direction is the time axis. For example, if the paper feeding speed is set to 10 sec/DIV, the number of dots of the printer 22 per 1 DIV is calculated. When configured with 50 points, the speed per dot line is 200 msec, so by sampling 200 times per dot line, it is possible to print the waveform shown in FIG. 3 as dots. In addition, such 1
Instead of the sampling number, a sampling time may be assigned to writing per dot line.

Similarly, the screen of the CRT display 24 is composed of a dot matrix, for example, 256 dots x 512 dots. However, 512 dots are on the horizontal axis,
Indicates the number of dot lines. This CRT display 24 includes a video RAM and a CRT controller. In addition, instead of the CRT display 24, a screen composed of dot matrix is displayed.
An LCD display or the like can be used as well.

Therefore, the RAM 20 dedicated to dot data storage has a capacity of, for example, 64 Kbytes, and
Addresses are assigned in correspondence with the dot matrix screen of the CRT display 24. That is, the fourth
As shown in the figure, one unit of memory is made up of 256 bits (one bit line), corresponding to one dot line consisting of 256 dots on the screen. Since this corresponds to 32 bytes, 64 Kbytes can constitute a circular buffer memory that cyclically uses write and read addresses expressed in hexadecimal numbers of 2048 bit lines. By the way, 1 byte corresponds to 8 bits, so
Dividing 256 bits by 8 bits gives 32 bytes,
64K bytes actually equals 65536 bits, so
Dividing 65536 bits by 32 bytes results in 2048 bit lines. Note that the number of bit lines must naturally be greater than the number of bit lines on the screen of the display 24. To write dot data created from input data to such a circular buffer memory 20, for example, first start from address 10000H.
Enter up to address 1001FH, and when you finish entering it,
Enter between addresses 10020H and 1003FH,
Furthermore, change the bit line and repeat the input in the same way, and when you reach address 1FFEOH, return to address 10000H, and so on. At that time, 1
For example, from address 10000H to 1001FH for each bit line.
At the address, as shown in Figure 5, if the sampled input data is 0, set the b0 bit of address 10000H to "1" according to the dot data created from that input data, and if the input data is 255.
Similarly, set bit b7 of address 1001FH to “1”. Incidentally, in order to fill in and interpolate the dots between sampling points on the screen to create a line representation, it is necessary to create and write interpolated data from input data. Further, in order to read from the circular buffer memory 20, the read address is set at an address after the write address, and the read is repeated by changing the address in the same manner.

Next, the operation of this embodiment will be explained.

FIGS. 6, 7, and 8 are flowcharts consisting of steps P1 to P23 showing an example of an input data processing program. To run this program, first set all addresses 10000H to 1FFFFH of the circular buffer memory 20 to 0 in P1.
Also, the video included in the CRT display 24
Set all RAM addresses to 0, and further set the sampling number DATA per 1 bit line to 0.
Next, go to P2 and set the write (input) address IN of the circular buffer memory 20 to address 10000H, and set the read (output) address OUT to address 10000H. Next, go to P3 and enable interrupts. Thereafter, the CPU 26 starts accepting sampling, and accordingly enters the interrupt routine shown in FIG. 7 in response to an interrupt signal every 1 msec from the timer 12. In this interrupt routine, first, A-
Data is input from the D converter 10. Next, go to P32 and convert the input data into dot data from the write address IN to the 32-byte bit line and write it once. Note that the first address of each bit line is an address representative of that bit line. next
Go to P33, add 1 to DATA and create a new
Create DATA and go to P34. In P34, DATA is the set sampling number per 1 bit line.
Determine whether it is 200 or more. If NO, the program returns to the point where the main program was interrupted. When an interrupt occurs again, the process goes through steps P31 to P33.
Perform P34 judgment. Thereafter, when the input data is sampled 200 times, all writing per 1 bit line is completed and YES is determined in P34, so the process goes to P35 and DATA is set to 0.
Next, go to P36, advance the write address IN by one bit line in preparation for the next similar process, and return to the main program. In this way, dot data is created from the input data sampled in time series, and the writing is repeated by changing the address IN of the circular buffer memory 20.

At P4, it is determined whether the stop switch key on the operation section 14 has been pressed. If NO, go to P5. In P5, write address IN is read address
Determine whether it is equal to OUT. In addition, the read address
OUT is set to an address one bit line after the write address IN. If NO, go to P6 and output one bit line from the read address OUT to the printer 22. At this time, the printer 22
One dot line is printed on the recording paper.
Next, go to P7, scroll (move) the screen of the CTR display 24 one dot line to the left, and P8
go to On P8, go to the one-dot line on the right edge of the screen,
Outputs 1 bit line (32 bytes) from read address OUT. That is, dot data for one bit line is written into the video RAM. Next, go to P9, advance the read address OUT by one bit line in preparation for the next similar process, and return to P4. After making the determinations in P4 and P5 again, steps P6 to P9 are repeated. In this way, the read address
Set OUT to an address after the write address IN,
The dot data is read out repeatedly by changing the address OUT from the circular buffer memory 20, printed on the recording paper of the printer 22, and displayed on the screen of the CRT display 24.

If YES in P4, go to P10 and disable interrupts. Next, go to P11 and read the normal read address.
Set a new read address OUT2 to an address 513 bit lines back from OUT. Next, go to P12, determine if there is a new key input, and YES
In this case, go to P13 and determine the type of the key. If the key (→) of the backward screen return switch is pressed, the process goes to P14, and it is determined whether the read address OUT2 is equal to the write address IN. Note that this determination is a process for preventing the circulation buffer memory 20 from outputting data for more than one round. If NO, go to P15,
Scroll the CRT display 24 screen one dot line to the right. Next, go to P16 and output one dot line from readout address OUT2 to the one dot line at the left end of the screen. That is, dot data for one bit line is written into the video RAM. Next, go to P17 and advance the read address OUT2 backward by one bit line in preparation for the next similar process. Next, go to P18 and read the normal read address.
Advance OUT backward by one bit line in preparation for the next similar process and return to P12. Again P12, P13, P14
After the determination, steps P15 to P18 are repeated. In this way, the readout address OUT2 is returned to an address one screen after the normal readout address OUT by key operation of the screen return switch, and then the readout is repeated by changing the address OUT2 from the circular buffer memory, and the CRT display 24 Display dot data indicating the previous screen on the screen.

Previous screen return switch key (←) on P13
In this case, go to P19 and read the normal read address.
Determine whether OUT is equal to write address IN. Note that this determination is also a process for preventing the circulation buffer memory 20 from outputting data for more than one round. If NO, go to P20 and scroll the CRT display 24 screen one dot line to the left. Next, go to P21 and output one bit line from the read address OUT to the one dot line at the right end of the screen. That is,
The dot data for one bit line is stored in the video RAM.
Write it in. Next, go to P22 and advance the read address OUT2 by one bit line in preparation for the next similar process. Next, go to P23, advance the normal read address OUT by one bit line in preparation for the next similar process, and return to P12. P12 again,
After making the determinations in P13 and P19, steps P20 to P23 are repeated. If the start switch key is pressed on P13, go to P1. Here, each time the start switch key (start), the stop switch key (stop), the backward screen return switch key (→), and the front screen return switch key (←) are operated, and the information displayed on the screen is displayed. An example of correspondence with waveform movements is shown in FIG. In this way, if you press the start switch key on the screen (A) where no waveform is displayed, the waveform will be displayed as on the screen (B), and the waveform will change as shown on the screen (C) and (D). do. However, when you press the stop switch key, the waveform stops as shown in the screen (e). Next, pressing the → key returns to the waveform display on the previous screen as shown in screen (f), and if you continue to press that key, the screen returns to the waveform display on the previous screen as shown in screen (g). Therefore, if the ← key is pressed, the screen returns to the waveform display in the opposite direction as shown in screen (H), and if the key is kept pressed, the waveform display returns to the waveform display in the screen in the further opposite direction as shown in screen (R). As a result, the waveform can be easily observed by returning to the previous screen as appropriate.

In the above embodiment, each address has an 8-bit structure, but if a 256-bit structure is used, it is only necessary to assign an address to each bit line.

Further, in the above embodiment, the circular buffer memory is used exclusively for storing dot data that depicts waveforms such as voltage, but a separate buffer memory for outputting to a printer or the like may be provided. For example, data for storage may be dedicated to waveforms, and data for output may be buffered including comment characters. Further, in addition to waveforms, dot data such as comment characters may also be stored in the circular buffer memory.

Also, in the above embodiment, output processing was performed for each bit line, but due to hardware reasons, etc.
Output processing may be performed on multiple lines at once.

In addition, in the above embodiment, the circular buffer memory
Although RAM was used, a floppy disk, etc. may also be used.

Further, in the above embodiment, the operating section is provided with a start switch, a stop switch, etc., but these are not essential and may be processed by a program.

Effects of the Invention According to the present invention described above, input data such as waveforms can be easily observed by returning to the previous screen as appropriate.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the structure of a recorder according to the present invention. FIG. 2 is a block diagram showing the configuration of a recorder to which the present invention is applied. FIG. 3 is a diagram showing an example of printing an input waveform by the same recorder using a dot matrix structure, and FIG. FIG. 5 is a diagram showing the state of writing to one bit line. 6th
7, and 8 are flowcharts showing an input data processing program adopted in the same recorder. FIG. 9 is a diagram showing an example of the correspondence between the operation time of each key on the same recorder and the movement of the waveform displayed on the screen of the CRT display. 10...A-D converter, 12...Timer, 14
...Operation unit, 18...Device equipped with CPU, 20
... Circulating buffer memory, 22 ... Printer, 2
4...Display, 26...CPU, 38...
Dot data input means, 40... dot data output means, 42... return screen output means.

Claims (1)

[Claims] 1. An A-D converter that converts analog input data into digital input data, an operation unit having a screen return instruction means for returning the display to the previous screen, a display that displays a screen composed of dot matrix, and a display Dot data is created from a circular buffer memory in which write and read addresses are configured cyclically with addresses assigned corresponding to the dot matrix screen, and input data sampled in chronological order, and dot data is generated at a fixed number of samples or over a fixed period of time. The dot data input means repeats writing by changing the address of the circular buffer memory each time, and the dot data input means sets the read address at an address after the write address, and repeats reading by changing the address from the circular buffer memory, and writes dot data on the screen of the display. What is claimed is: 1. A recorder comprising: dot data output means for display; and return screen output means for returning addresses from a circular buffer memory in reverse chronological order by operating a screen return instruction means.