KR100298038B1 - driving installation and driving method of dot matrix numeric display - Google Patents

Abstract

The present invention relates to a method and apparatus for displaying decimal data on a 4x7 dot matrix decimal display.

The part that makes the 4-digit decimal data signal and the toggled latch enable signal to be displayed on the decimal indicator into one instruction on the computer, and the command that is made on the computer repeatedly to the decimal indicator assembly and the decimal indicator assembly Characterized in that the decimal display by driving the decimal display with a signal sent to the, characterized in that the drive method can reduce the number of PLC output terminals, there is an effect that can minimize the work of the PLC internal program.

Description

Driving installation and driving method of dot matrix decimal display

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for displaying decimal data on a 4x7 dot matrix decimal display. The present invention relates to a "4-digit decimal data signal" and a toggled "latch enable signal". A single instruction from the computer is then sent twice to the decimal display to software generate a "latch enable signal" with a settling time (t _w ) and a rising edge, and then the "latch enable signal" The present invention relates to a method and an apparatus for displaying a "four-digit decimal number" transmitted from a computer to a decimal display assembly.

First, a PLC (hereinafter, referred to as a programmable logic controller) will be described.

A programmable logic controller is a digital controller that inputs a digital or analog signal from a plant, performs a control operation using a user program stored in a memory of the programmable logic controller, and repeats a series of tasks of outputting the result. These programmable logic controllers perform well for simple computations, but there are many limitations to perform advanced computations such as signal processing.

As an example, we will look at displaying 4-digit decimal data on 16 decimal indicator assemblies in a conventional manner.

First, 16 data signals and 1 latch enable signal are required to drive one decimal indicator assembly, and 17 programmable logic controller output terminals are required to interface one decimal indicator assembly in the programmable logic controller. And, to drive 16 decimal indicator assemblies requires a total of 272 programmable logic controller outputs, 17 × 16, so the number of decimal indicators to use increases the number of programmable logic controller outputs required, which can be expensive. A problem occurs.

It also drives 16 decimal indicator assemblies, reducing the number of programmable logic controller outputs from 272 to 32 without any additional hardware configuration. Of the 32 outputs, 16 outputs are connected to the latch enable signal and the remaining 16 Output terminals are connected to the data signal, and the 4-digit decimal number generated by the computer is displayed on the decimal display assembly. In the computer, the decimal data signal and the address of the decimal display assembly are spaced apart. Since they occur simultaneously without a time interval, decimal data is loaded into the decimal indicator assembly, but decimal data cannot be latched. Therefore, a problem arises in that an arbitrary data value is displayed only in a blinking state.

The present invention has been made to solve the above-mentioned conventional problems,

Programmable Logic This command generates programmable logic by reducing the number of output terminals of the controller and continuously generating instructions on the computer to create the settling time (t _w ) required for the latch enable signal without the need for additional hardware. The present invention relates to a method and an apparatus for displaying a "four-digit decimal number" generated by a computer on a decimal display assembly by passing it to a decimal display through a controller.

1 is a block diagram of the present invention.

2 is a decimal controller assembly connection diagram.

3 is a data format generated by the host computer.

4 is a timing diagram for latching data on a decimal indicator.

5 is a flow chart for sending the host computer's variable values to the multiplexed 16 decimal indicator assemblies.

<Description of the symbols for the main parts of the drawings>

100: main computer 110: programmable logic controller

120: plant 130: main control panel

140: decimal indicator assembly 150: TCP / IP network

160: flat cable 300: data format

310: data signal 320: latch enable signal

330: Number of bytes transmitted 340: Programmable logic controller address

400: data load signal 410: data latch signal

A feature of the present invention for achieving the above object is the generation of a command that generates a settling time (t _w ) and a command that generates rising edges in a computer successively, and passing the command to a decimal indicator through a programmable logic controller to a decimal indicator. Solves the problem of decimal data being loaded into the decimal indicator assembly but not latched and displayed only in the flashing state and directly driving the decimal indicator on the computer without the aid of a program inside the programmable logic controller. Generate and drive the decimal indicator, increasing data transfer speed, minimizing the work of the programmable logic controller internal program, and assembling 16 decimal indicators by multiplexing and sending data to be sent to the decimal indicator from the main computer. The logic is driven by only 32 programmable logic controller outputs, reducing the number of programmable logic controller outputs required.

1 is a configuration diagram of the system proposed in the present invention,

In the present invention, the driving device and driving method of the dot matrix decimal display read the input variable of the plant 120 using the programmable logic controller 110, and the value is converted into an Ethernet communication network. 150 to transmit to the main computer 100 to perform a signal processing operation in the main computer 100, and then transfer the calculated result directly to the output terminal of the programmable logic controller 110 to drive the decimal indicator. And

According to the driving device and the driving method described above, the arithmetic function of the programmable logic controller 110 is supplemented, and the programmable logic controller for driving the decimal display assembly by multiplexing data from the main computer 100 and transmitting the data to the decimal display assembly ( 110) The number of output terminals can be significantly reduced.

Decimal display assembly 140 is a latch function as shown in FIG. 2 to display the 4-digit decimal value calculated by the main computer 100, that is, the variable value of "0000"-"9999" to the main control panel 130. Four 4x7 dot matrix type decimal indicators are installed on a PCB to create a decimal indicator assembly, and the latch enable signals of the four decimal indicators are grouped together in a common line. Configures ten decimal indicators to be selected.

As shown in FIG. 2, the 16 decimal indicator assembly 140 is connected to the 32 line flat cable 160, and 16 lines of the 32 line flat cable 160 are used to convey "decimal data" to be displayed on the 4 decimal indicators. The remaining 16 wires are used as a "latch enable" signal for selecting 16 assemblies 140.

A 32-wire flat cable 160 connecting 16 decimal indicator assemblies 140 connects to 32 programmable logic controller digital output terminals.

3 is a data format 300 for representing four-digit &quot; decimal data &quot;. The number of programmable logic controller output terminals can be configured by configuring the latch enable signal in software without any hardware configuration. Can be reduced.

The data format 300 includes 16 bits 310 of information indicating "decimal data" in the host computer 100, 16 bits 320 of "address of the decimal indicator display" information to be used as a latch enable signal, and "length of data to be transmitted." Information 16 bits 330 and a "start address of the programmable logic controller output terminal" 340 to transmit this value.

The generated data format 300 is transferred to the programmable logic controller 110 via an Ethernet communication network 150 by a program in the main computer 100, and the programmable logic controller 110 is connected to the main computer 100. Analyzes the contents of the data format 300 transmitted from the data stream and transmits 16-bit "decimal data" information and 16-bit "assembly address" information to the 32 output terminals designated by the "start address of the programmable logic controller output terminal". And display a four digit decimal number on the corresponding decimal indicator assembly 140 connected to the programmable logic controller output terminal.

In the same manner as described above, the host computer 100 generates all data formats 300 to be transmitted to each of the 16 decimal indicator assemblies 140.

In order to deliver the 16 data formats 300 to each decimal display assembly 140 via 32 programmable logic controller digital output terminals, a process of multiplexing the data formats 300 produced by the host computer 100 is required. The "start address of the programmable logic controller output terminal" of the 16 data formats 300 should be set identically, and corresponding bits of the "decimal indicator assembly address" are the values given in "Latch Enable Signal" of FIG. Will be set.

As shown in FIG. 5, the multiplexed data format 300 repeatedly sends "decimal data" and "latch enable signal" to the same programmable logic controller start address, so that the 16 decimal indicator assembly ( 140 can be driven.

In addition, the present invention maintains the settling time (t _w ) in software without additional hardware and transitions the logic level from L _L to L _H , so that the variable value transmitted from the main computer 100 is displayed on the assembly. It is

The example below is part of a program that performs this function (see attached Figure 4).

* Load "4321" into the first decimal indicator assembly *

strcpy (send_data, '0000200004FFFE4321');

length = strlen (send_data);

send (sockfd, send_data, length, 0);

* Latch '4321' in the first decimal indicator assembly *

strcpy (latch_data, '0000200004FFFF4321');

length = strlen (latch_data);

send (sockfd, latch_data, length, 0);

That is, the main computer 100 transmits the 16-bit information 310 representing "decimal data" to the programmable logic controller 110 and the 16-bit 320 information of the "address of the decimal display assembly" to be used as the latch enable signal. When the data format &quot; 0000200004FFFE4321 &quot; created by combining the data length &quot; 16 bits &quot; information 330 and the &quot; start address of the programmable logic controller output terminal &quot; 340 to transmit this value is transmitted, the programmable logic controller 110 can display &quot; 000020 &quot; From the address, FFFE4321 is delivered to 32 programmable logic controller output terminals.

Here, "4321" is an actual variable value to be displayed on the decimal display, and "FFFE" is used as a signal for maintaining the logic level of the "Latch Enable" signal of the first assembly at L _{L. The} "Latch Enable" signal. the logic level of the variable value passed in L _L state is not displayed "4321" is a decimal number as the indicator will only load (load) to the assembly. 400

In order to latch and reliably display the variable value "4321" loaded in the decimal indicator assembly 140, the logic level of the "latch enable" signal must be shifted from L _L to L _H. 16 bits of information 310 and address of decimal indicator assembly to be used as latch enable signal 16 bits of information 320 and length of data to be transmitted 16 bits 330 of programmable logic controller output It is necessary to transmit the variable value having the format of "0000200004FFFF4321" formed by combining the start address "340 from the main computer 100 to the programmable logic controller 110 once more.

Through this transfer, the "Latch Enable" signal is changed from "FFFE" to "FFFF", and the logic level value is shifted from L _L to L _H , and the four-digit decimal "4321" received from the host computer by this transition is a decimal indicator. Shown at (410).

In order to display the four-digit decimal number "8765" in the second assembly, the host computer 100 uses the data format for data loading, that is, the information 16 bits 310 indicating "decimal data" and the "decimal number" to be used as a latch enable signal. "0000200004FFFD8765" and data created by combining 16 bits 320 of the address information of the indicator assembly, 16 bits 330 of the length of the data to be transmitted, and start address of the programmable logic controller output terminal 340 to transmit the value. "0000200004FFFF8765" for the latch is transmitted to the programmable logic controller 110 twice in succession.

As shown in Fig. 5, the above process is repeated as many decimal indicator assemblies to finally display four decimal digits in all sixteen decimal indicator assemblies.

Although the present invention has been shown and described with respect to particular embodiments, those skilled in the art will recognize that various modifications and changes can be made without departing from the spirit and scope of the invention as indicated by the appended claims. Anyone can easily know.

The present invention continuously generates instructions for generating a settling time (t _w ) and instructions for generating rising edges on a host computer, and then delivers the instructions to the decimal display via a programmable logic controller directly at the computer to drive the decimal display. Programmable Logic Controller By directly generating the decimal display from the computer without the help of the program, the decimal display is driven. This increases the data transfer speed and minimizes the work of the programmable logic controller.

The main computer uses only 32 programmable logic controller outputs to drive the decimal number in the 16 decimal indicator assembly by sending the data to the decimal indicator in data format and sending it twice in succession, resulting in programmable This reduces the number of logic controller output terminals by 88%.

Claims (2)

A device for driving a dot matrix decimal indicator that displays a decimal number by using a programmable logic controller as an interface to transfer information of a main computer to a dot matrix decimal display. Means for creating a data format by combining the assembly address of the decimal data with the decimal indicator in the host computer, the length of the data to be transmitted and the start address of the programmable logic controller output; Means for transmitting the data format to an interface output terminal; Means for maintaining a latch enable signal at a logic level low (L _L ) for a settling time (t _w ) to securely store data in the decimal indicator assembly during the transmission; Means for generating a latch enable signal having a rising edge after holding for a settling time t _w to display decimal data on the decimal indicator assembly; And Decimal indicator driving device having a function of repeating the above steps by a decimal indicator assembly number. A method of driving a dot matrix decimal indicator that displays a decimal number by using a programmable logic controller as an interface to transfer information of a main computer to a dot matrix decimal indicator. Creating a data format in the host computer by combining the assembly address of the decimal data with the decimal indicator, the length of the data to be transmitted and the start address of the programmable logic controller output; Transmitting the data format of the step to an interface output terminal; Holding the latch enable signal at a logic level low (L _L ) for a settling time (t _w ) to securely store data in the decimal indicator assembly upon transmission of the step; Generating a latch enable signal having a rising edge after holding for a settling time t _w to display decimal data on the decimal indicator assembly; And And repeating the above steps by a decimal indicator assembly number.