JP2011108070A - Scale transformation method of analog data - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To readily prepare a user program, since there is no need to prepare a program for scale-transforming analog data into digital data, in preparing the user program. <P>SOLUTION: A scale conversion method includes a first step of calling a scale conversion window onto a user program preparing screen of a programming tool; a second step of filling the input range of the analog data and the scale conversion range, corresponding to this into the scale conversion window with the programming tool; a third step of fixing the filling; and a fourth step of incorporating, as firmware, a program for performing the scale conversion to digital data, having the content corresponding to the filling into a PLC based on the filling. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to making it possible to create a user program more easily without the need for creating a program for scale conversion of analog data in programming a user program of a programmable controller (PLC).

  The PLC controls the machine according to a user program, and includes a PLC module and various input / output modules that input / output signals to / from the PLC module. The input / output module includes an input module, an output module, and the like. The PLC module includes a CPU that executes a user program according to firmware, various programs, and various memories that store data such as calculation results of the CPU. The user program is designed by a programming tool. The program designer designs the user program with the programming tool and then transfers the user program to the PLC. The user program transferred to the PLC is stored in the program memory. The PLC executes the user program according to the firmware (see, for example, Patent Document 1).

JP 2009-015751 A

  In the above-described PLC, an analog signal related to temperature detection from, for example, a temperature sensor which is an input device in the input module is converted into a digital signal and then input to the PLC module. The PLC module processes the digital signal from the input module according to the user program. In this case, when the analog signal represents a temperature range of 0 to 100 ° C. in a voltage range of 0 to 5 V, for example, the user who is a program designer converts the analog signal of 0 to 5 V to a 12-bit digital signal of 0 to 4095. In the case of A / D conversion and input to the PLC module, the user program in the PLC module needs to perform scale conversion (scaling) on the digital signal. In this case, the voltage range of 0 to 5 V is not scaled to the temperature range of 0 to 100 ° C., but other voltage ranges, for example, 1 to 3 V are scaled to the above temperature range, or 0 to 5 V The voltage range may be scaled to a temperature range of −50 to 120 ° C.

  If it explains in detail, it is 0-4095 in 0-100 degreeC with respect to 0-5V, 0-100 degreeC with respect to 1-3V, and -50-120 degreeC with respect to 0-5V. Since the scale conversion concept is introduced, the user who is the program designer will eventually handle the scale conversion among the three parties, so it is necessary to incorporate a scale conversion program corresponding to the three parties in the PLC module. The program design has become very complicated and the program design has become troublesome.

  Therefore, in the present invention, when analog data scale conversion is performed in creating a user program, it is an object to be solved to eliminate the need to handle digital data by scale conversion and facilitate the creation of the user program.

  The analog data scale conversion method in the PLC according to the present invention includes a step of calling a scale conversion window on a user program creation screen of a programming tool, an input range of analog data in the scale conversion window, and a scale corresponding thereto. The step of entering the conversion range with a programming tool, the step of confirming the entry, and the confirmation confirms that the user program has a program that performs scale conversion into digital data with the contents corresponding to the entry as firmware. And a step of incorporating.

  In the above PLC, for example, when a temperature detection signal from a temperature sensor is input to the analog input module in the form of analog data, the temperature detection signal from the analog input module to the PLC module is scaled from an analog data format to a digital data format. Need to convert. In this case, enter the analog data input range and the corresponding scale conversion range on the scale conversion window, and confirm the entry to convert the temperature detection signal from analog data format to digital data format. Therefore, the user does not need to create a program for converting the temperature detection signal from the analog data format to the digital data format, and the user program can be easily created.

  According to the present invention, it is not necessary to create a program for converting analog data to digital data when creating a user program, so that it is easy to create a user program.

FIG. 1 is a diagram showing a temperature monitoring control system according to an embodiment of the present invention. FIG. 2 is a diagram showing a block configuration of a PLC module in the PLC of FIG. FIG. 3 is a diagram showing a part of a ladder program executed by the PLC module in the PLC of FIG. FIG. 4 is a diagram showing an editing screen of the programming tool. FIG. 5 is a diagram showing the editing screen of FIG. 4 and the scale conversion window called on the editing screen. FIG. 6 shows the scale conversion window of FIG. 5 in detail. FIG. 7 shows another scale conversion window in detail.

  Hereinafter, a method for converting the scale of analog data in a PLC according to an embodiment of the present invention will be described with reference to the accompanying drawings. FIG. 1 shows the configuration of a temperature monitoring control system that implements this method. Referring to FIG. 1, 1 is a temperature sensor, 2 is a PLC, 3 is a display lamp for temperature monitoring, and 4 is a programming tool.

  The temperature sensor 1 is a sensor that can detect the temperature of a control target (not shown) within a predetermined temperature range, and can output a voltage corresponding to the detected temperature as an analog temperature detection signal. The temperature sensor 1 is a sensor that can output an analog temperature detection signal in the voltage range V1 to V2 with respect to the detection temperature range t1 to t2 ° C., for example, specifically, for example, in the detection temperature range 0 to 100 ° C. On the other hand, an analog temperature detection signal can be output in a voltage range of 0 to 5 V, for example. Of course, the temperature sensor 1 may be a sensor that outputs an analog temperature detection signal in another voltage range of 1 to 3 V with respect to the same detection temperature range of 0 to 100 ° C. A sensor that can output an analog temperature detection signal in a voltage range of 0 to 5 V with respect to a detection temperature range of −50 to 120 ° C. may be used. In the embodiment, for convenience of explanation, an analog temperature detection signal is output in a voltage range of 0 to 5 V with respect to a detection temperature range of 0 to 100 ° C.

  The PLC 2 includes an analog input module 2a, a PLC module 2b, and a digital output module 2c. Note that these modules 2a, 2b, and 2c are not in a module form, and may be referred to as an analog input unit 2a, a PLC unit 2b, and a digital output unit 2c as functional names in the PLC 2.

  The analog input module 2a outputs an analog temperature detection signal in the voltage range 0 to 5V from the temperature sensor 1 as a digital value in the digital range 0 to 4095.

  The PLC module 2b executes a ladder program corresponding to the digital value input from the analog input module 2a and controls lighting of the display lamp 3 via the digital output module 2c. As shown in FIG. 2, the PLC module 2b includes a ladder program execution CPU b1, a firmware (system control program) storage memory b2, a ladder program storage memory b3, an internal memory b4 for storing data related to the results of control operations, It has an output interface b5, a communication interface b6, and a scale calculator b7. An analog input module 2a and a digital output module 2c are connected to the input / output interface b5. A programming tool 4 is connected to the communication interface b6.

  The digital output module 2c drives the display lamp 3 by a control signal from the PLC module 2b.

  The display lamp 3 includes a plurality of color display lamps, for example, a yellow display lamp 3a, a green display lamp 3b, and a red display lamp 3c. In the display lamp 3, the yellow display lamp 3a has an output Y1 from the digital output module 2c, the green display lamp 3b has an output Y2 from the digital output module 2c, and the red display lamp 3c has an output Y3 from the digital output module 2c. Flashes on. Each of the display lamps 3a to 3c is controlled in light emission by a ladder program shown in FIG. In this ladder program, if the temperature detected by the temperature sensor 1 is less than 20 ° C., the input X1 is turned on, the output Y1 is output from the digital output module 2c, and the yellow display lamp 3a is turned on. If below, the inputs X2a and X2b are turned on, the output Y2 is outputted from the digital output module 2c and the green display lamp 3b is lit, and if it exceeds 80 ° C., the input X3 is turned on and the digital output module 2c This is a program for outputting the output Y3 to light the red display lamp 3c.

  The PLC module 2b receives a digital conversion value in the range from 0 to 4095 related to the temperature detection of the temperature sensor 1 from the analog input module 2a. The firmware memory b2 stores firmware for the scale calculator b7 to perform scale conversion calculations. When an analog temperature detection signal having a digital value in the range from 0 to 4095 is input from the analog input module 2a, the CPU b1 performs scale conversion of the digital value by the scale calculation unit b7, and the ladder of FIG. The program is to be executed.

  The firmware for the scale calculation will be described with reference to FIG. FIG. 4 shows an editing screen 4 a of the programming tool 4. On the editing screen 4a, the ladder program of FIG. 3 is displayed. Then, the scale conversion window W1 is displayed on the editing screen 4a as shown in FIG. The edit screen 4a has a title bar, a menu bar, a tool bar, a status bar, and the like, and the screen configuration is divided into a plurality of areas as a user interface screen. In the embodiment, a ladder diagram edit area A1, navigation An area (Navigation) A2 and a parts list area (Instruction List) A3 are provided.

  By operating each area of the editing screen 4a with an operation unit such as a mouse or a keyboard provided in the programming tool 4, operations such as editing, correction, and change of the ladder program are performed. A ladder diagram is displayed in the ladder diagram editing area A1. In this ladder diagram, a ladder program portion is displayed. The device contacts constituting this ladder program part are arranged by selecting the ladder component displayed in the component list area A3. The ladder part is selected from the parts displayed as “Contact”, “Coil”, “Timer / Counter”, etc. in the ladder part list area A3. In the navigation area A2, there are displays such as “Ladder Program” and “Monitor”. By focusing on each display area and clicking the mouse, various screens can be called on the editing screen 4f in a window format.

  As shown in detail in FIG. 6, the scale conversion window W <b> 1 displays “5.0” and a minimum value (Min) in the maximum value (Max) entry boxes 10 and 10 a in the input range 0 to 5 V of the temperature sensor 1 that is analog data. ) “0.0” in the entry boxes 11, 11 a, “100.0” in the scale conversion value entry boxes 12, 12 a corresponding to the maximum value (Max) entry boxes 10, 10 a, and the minimum value (Min) entry box 11, “0.0” is entered in the scale conversion value entry boxes 13 and 13a corresponding to 11a. After this entry, the entry is confirmed by clicking “OK” with the mouse. After this determination, the scale conversion firmware is set in the firmware memory b2 of the PLC module 2b, and the scale calculation unit b7 performs the scale conversion calculation according to the scale conversion firmware. As a result of this calculation, if the temperature detected by the temperature sensor 1 is less than 20 ° C., the input X1 is turned on, the output Y1 is output from the digital output module 2c, and the yellow display lamp 3a is turned on. If the temperature is 80 ° C. or lower, the inputs X2a and X2b are turned on, the output Y2 is output from the digital output module 2c and the green display lamp 3b is lit. If the temperature is higher than 80 ° C., the input X3 is turned on and the digital output module The output Y3 is output from 2c, and the red display lamp 3c is lit.

  In the scale conversion window W2 shown in FIG. 7, for example, the scale conversion range is set to 0 to 100 in the PLC module 2b, and “100.0” and “0.0” are entered in the scale conversion entry boxes 14, 14a, 15, and 15a. When “5.0” is entered in the maximum value entry boxes 16 and 16a of the output range and “0.0” is entered in the minimum value entry boxes 17 and 17a of the output range for the scale conversion, the digital output module The display lamps 3a to 3c can be controlled to be lit within the above voltage range from 2c.

  As described above, in the present embodiment, when the temperature detection signal from the temperature sensor 1 is input to the analog input module 2a in the form of analog data, the temperature detection signal from the analog input module 2a to the PLC module 2b is in the analog data format. Scale conversion from digital to digital data format. In this case, the analog data input range and the corresponding scale conversion range are entered on the scale conversion window W1, and the scale is converted from the analog data format to the digital data format simply by confirming this entry. Since the conversion is performed as firmware, the user does not need to create a program for converting the temperature detection signal from the analog data format to the digital data format, and the user program can be easily created.

  In the embodiment, the temperature monitoring control system is exemplified, but the present invention is not limited to this system.

1 Temperature sensor (input device)
2 PLC
2a Analog input module 2b PLC module 2c Digital output module 3 Indicator lamp 4 Programming tool

Claims (1)

A first step of calling a scale conversion window on a user program creation screen of a programming tool;
A second step of entering an analog data input range and a corresponding scale conversion range by a programming tool in the scale conversion window;
A third step to confirm the entry,
A fourth step of incorporating into the PLC as firmware a program for performing scale conversion into digital data with the contents corresponding to the entry by the confirmation;
A method for scaling analog data in a PLC, comprising:

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