JP2914100B2 - Analog signal processor for programmable controller - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an analog signal processor for a programmable controller mounted on a main body of a programmable controller and controlling an analog voltage or an analog current.

[0002]

2. Description of the Related Art A conventional technique will be described. FIG.
1 is a configuration diagram of a programmable controller (hereinafter, referred to as a PC) using a conventional analog input / output unit. In the figure, reference numeral 170 denotes a CPU unit of a PC mounted on the main body of the programmable controller, 171 denotes a sequence processing unit for processing a sequence program, 172
Is a sequence program memory for storing a sequence program, 173 is an interface unit for exchanging data with the analog input / output unit, 174 is an analog input / output unit, 175 is a processing unit for managing the overall operation of the analog input / output unit, Reference numeral 176 denotes an A / D conversion value memory for the analog input / output unit 175 to transfer the A / D conversion value to the CPU unit 170, and 177 is used when the CPU unit 170 transfers the D / A conversion value to the analog input / output unit 175. A D / A conversion value memory 178, an A / D converter for converting an analog amount into a digital value, 17
9 is an analog input unit, 17a is a D / A converter for converting a digital value into an analog amount, 17b is an analog output unit, 1
Reference numeral 7c denotes an object to be controlled in the control system, and reference numeral 17d denotes a switch unit for setting an offset value and a gain value of the A / D conversion unit 178 and the D / A conversion unit 17a of the analog input / output unit 174.

FIG. 19 is a diagram showing an example of a sequence program for controlling this system. In the figure, reference numeral 181 denotes A / A from the analog input / output unit 174.
The D-converted value is read, and a value to be D / A-converted is calculated by an arithmetic processing.
Sequence program to be written into D conversion value memory, 18
0 and 182 are sequence programs for other processing.

Next, the operation will be described. First, the analog input signal from the control target 17c is converted, and the A / D
The operation until the data is stored in the conversion value memory unit 176 will be described. An analog signal indicating the state of the control target 17c is input to an analog input unit 179 and then converted to a digital value by an A / D conversion unit 178. The A / D converted value is written to the A / D converted value memory 176. This series of processing is sequentially repeated by the processing unit 175, and the digitally converted value of the analog signal amount input to the analog input unit 179 is sequentially stored in the A / D conversion value memory 176.

Next, the operation of the sequence processing section 171 fetching an A / D converted digital value, performing arithmetic processing, and writing the result in the D / A converted value memory 177 will be described. The sequence processing section 171 processes the analog input / output unit program 181 shown in FIG. 19 while repeatedly processing the first step to the last step of the program stored in the sequence program memory 172. A / D-converted values are read from the A / D-converted value memory 176 by the analog input / output unit program 181, and D / A-converted values are calculated by a program that executes a function formula combining four arithmetic operations and the like, The data is written to the D / A conversion value memory 177.

After the analog input / output unit program 181 is executed once, there is a time interval between the next execution of the analog input / output unit program 181. This interval corresponds to a cycle time from when the sequence processing unit 171 processes the first step to the last step of the sequence program until the process returns to the first step again. The larger the size of the sequence program, the longer this cycle time Is also longer. Processing unit 1
A process 75 periodically reads the digital value written in the D / A conversion value memory 177, converts the digital value into an analog amount by the D / A conversion unit 17a, and outputs the analog value to the control target 17c via the analog output unit 17b. Has been repeated.

Next, setting of the offset value and the gain value of the A / D converter 178 and the D / A converter 17a will be described. First, the setting of the offset value and the gain value of the A / D conversion unit 178 is performed externally by the analog input unit 17.
A voltage of 0 V for setting an offset value and a voltage of 10 V for setting a gain value are applied to 9, and in each case, an offset setting switch (not shown) and a gain setting switch (not shown) of the switch section 17 d are turned on. As a result, the conversion output of the A / D conversion section 178 is stored in the offset / gain storage section 1c as an offset value and a gain value. The setting of the offset value and the gain value of the D / A conversion unit 17a is performed by connecting a voltmeter to the analog output unit 17b,
The output voltage of the analog output unit 17b is set to 0V when an offset value is set by an up / down switch (not shown) of the switch unit 17d, and 10V when a gain value is set.
Adjust so that When the voltage is adjusted to 0V, the input value of the D / A converter 17a is stored as an offset value in the offset / gain storage unit 1c by the offset setting switch of the switch unit 17d, and when the voltage is adjusted to 10V, the switch unit 17d is adjusted. The input value of the D / A conversion unit 17a is stored as a gain value in the offset / gain storage unit 1c by the gain setting switch.

[0008]

The conventional analog input / output unit 174 executes only a process of converting an analog input amount from the control target 17c into a digital value and a process of converting a digital value into an analog output amount. The arithmetic processing for determining the analog output amount with respect to the analog input amount is P
The CPU unit of C is performing. For this reason, the delay time until the analog output amount changes with respect to the change in the analog input amount largely depends on the period time required for the A / D conversion and the D / A conversion and the cycle time in which the sequence program is processed. Also, the larger the sequence program is, the longer this delay time is, and the control target 1
Conventionally, there has been a problem that it becomes difficult to control 7c with high speed and high accuracy.

Here, for the analog input / output unit
An operation means for performing a predetermined operation is provided, and a sequence
Analog output amount to analog output amount independent of program
When calculating and outputting this, for example, when turning on the power
When starting, the analog output is
Changes instantaneously from the amount of input to the amount of output calculated
Therefore, there is a problem that the control target 1b is shocked.
Sometimes.

The conventional analog input / output unit 17
In No. 4, for each analog input channel or analog output channel, the offset value and gain value could only be set to fixed values. In the analog input / output unit 174, it is general that either 0-10 V or 4-20 mA is used as a specified condition voltage or specified condition current of the offset value and the gain value of each channel. Therefore, the manufacturer of the unit sets the offset value and the gain value at either 0-10 V or 4-20 mA before shipping, but the user sets the offset value and the gain under specified conditions different from the manufacturer's settings. You may want to set a value and use it. In this case, there is a problem that the user has to set the offset value and the gain value again.

The conventional analog input / output unit 174
When setting the offset value and gain value of the analog input channel in, the voltage for setting the offset value and the voltage for setting the gain, or the current for setting the offset and the current for setting the gain are externally input to the analog input channel. After the voltage is applied to the channel, a predetermined switch provided in the unit is turned on, and the offset value and the gain value are stored. On the other hand, in the case of setting the offset value and the gain value in the analog output channel, the voltage or current output by the switch provided in the unit is increased or decreased, and then another predetermined switch is turned on to set the offset value. And the gain value were stored. That is, there has been a problem that manual operation of the switch is required for setting the offset value and the gain value of both the analog input channel and the analog output channel.

The present invention has been made to solve the above-mentioned problems, and has the following objects.
You.

The analog output to be output to the object to be controlled is switched off.
To get an interchangeable analog signal processor
Aim.

It is another object of the present invention to easily set or change the offset value and the gain value.

It is another object of the present invention to easily set an offset value or a gain value.

[0016]

A program according to the present invention is provided.
The analog signal processor for the mable controller
Programmable components that operate based on
Programmable controller provided in the controller
Analog signal processing device, input from control object
A / A that converts the analog input signal to a digital signal
D conversion means and a conversion output of the A / D conversion means.
Based on instruction information from the programmable controller itself
Operation means for performing an operation according to a predetermined function formula;
Calculation output calculated based on the means or programmable
Select one of the command values from the controller
Selecting means, and the arithmetic output or the arithmetic output selected by the selecting means.
Outputs an analog output based on the command value to the control target.
An output unit that is the also equipped with.

The offset value and the gain of the A / D conversion
In value, D / A conversion offset value and gain value
It has a plurality of storage means for storing, from this plurality of storage means
Offset value based on the storage content of the selected storage means
And a gain value.

Also, an analog input input from a control object is provided.
A / D conversion means for converting a force signal into a digital signal,
An operation for performing a predetermined operation on the conversion output of the A / D conversion means
Means, an analog output based on the operation output of the operation means
Output means for outputting to a controlled object
Analog signal processor for
D / A change by command from Gramble Controller
Voltage reading means or current capable of reading the conversion output of the conversion means
Read means and command of programmable controller
A predetermined voltage value or current value is output based on this output
Input to the A / D conversion means.
Power supply and the constant voltage power supply or the constant current power supply
Is the conversion output of the A / D converter when the current value is output.
Store the value as an offset value or gain value for A / D conversion.
Write to the column and the programmable controller itself
More based on the reading output of the voltage reading means or current reading means
Command to increase or decrease the input value to the D / A conversion means
And a predetermined voltage value by the voltage reading means or the current reading means.
Alternatively, the input value when a predetermined current value is read is changed by D / A conversion.
Write to the storage means as a new offset value or gain value
Writing means.

[0019]

[Action] Programmable controller in the present invention
Analog signal processor for programmable controllers
Selection means is programmable based on commands from the
Command value from the controller body or calculation of the calculation means
One of the outputs is selected and output, and the output means selects this output.
And outputs an analog output based on the control object.

The offset value and the gain of the A / D conversion
In value, D / A conversion offset value and gain value
It has a plurality of storage means for storing, from this plurality of storage means
Offset based on the storage content of the selected storage means
Value and gain value are set.

In addition, the programmable controller
The constant voltage power supply or constant current power supply
When a voltage value or a current value is input to the A / D conversion means,
The conversion output of the A / D conversion means is A / D converted by the writing means.
Is written to the memory as the offset value or gain value of
And voltage reading means or current reading means
A program based on the read conversion output of the D / A conversion means.
Input from the main controller to the D / A converter
A command to increase or decrease the value is issued, and the conversion output of the D / A converter is output.
D / A conversion when the voltage reaches a predetermined voltage value or a predetermined current value
The input value of the conversion means is an offset value of D / A conversion or a gay value.
Is written into the storage means by the writing means.

[0022]

【Example】 Embodiment 1 FIG. FIG. 1 shows an analog input / output unit according to the present invention.
FIG. 2 is a configuration diagram of a control system according to an embodiment.

In the figure, reference numeral 10 denotes a programmable controller.
The CPU unit 11 of the PC mounted on the roller body, 11
Sequence processing unit for processing a sequence program, 1
2 is a sequence program for storing a sequence program.
Program memory 13 is analog input / output unit and data
Interface for sending and receiving data, 14 is a program
Programmable mounted on the ramable controller body
Analog signal processing device for controller, for example, analog
It is an input / output unit.

Reference numeral 15 denotes the entire analog input / output unit 14
16 is a processing unit for managing the operation of the PC.
Dual port memo for exchanging data with 10
A / D converter 17 for converting an analog amount into a digital value.
Conversion means, for example, an A / D converter.

Reference numeral 18 denotes an analog input unit, and 19 denotes a digital value.
D / A conversion unit for converting into an analog amount, 1a is an analog
The output unit, 1b is the control object, 11c is the offset value and
And gain value storage unit.
You.

[0026] The calculation means may be embodied by the processing unit 15, output means is constituted by D / A converter 19 and the analog output section 1a.

FIG. 2 shows the dual port memory 16 of FIG.
FIG. In the figure, reference numeral 20 denotes an A / D conversion value memory for storing a digital value obtained by converting an analog input amount, and reference numeral 21 denotes a CPU for storing a digital value for analog output.
A D / A conversion value memory for CPU written by the sequence processing unit 11 of the unit 10, a calculation result storage memory 22 for storing a value calculated by the processing unit 15 of the analog input / output unit 14 from an analog input amount based on a function formula , 23
Is a D / A output permission memory storing information indicating whether or not output of an analog output is permitted, and 24 is one of an offset value and a gain value stored in the offset / gain storage unit 11c. Offset / gain selection memory for storing information indicating the D
An output switching memory for storing information specifying which of the / A conversion value memory 21 and the operation result storage memory 22 to output a value, 26 is a constant for storing a constant parameter A in a function expression Parameter A memory 27 is a constant parameter B for storing a constant parameter B in the function formula.
Memory.

28 is an analog input amount 1 memory, 29 is an analog output amount 1 memory, 2a is an analog input amount 2 memory, 2b is an analog output amount 2 memory, 2c is an analog input amount 3 memory, 2d is an analog output amount 3 memory And
Each value stores the relationship between the analog input amount and the analog output amount. 2e selects A / D conversion or D / A
A / D, D in which information for selecting or specifying conversion is stored
/ A conversion memory, 2f is an offset command memory storing information indicating whether to store an offset value, 2g is a gain command memory storing information indicating whether to store a gain value, and 2h is D The output down command memory 2i stores information indicating whether or not to increase the analog output amount during the offset / gain setting of the A / A converter.
This is an output down command memory for storing information indicating whether or not to reduce the analog output amount during the setting of the offset / gain of the / A conversion unit.

FIG. 3 is a diagram showing a sequence program executed by the sequence processing section 11. In the figure, reference numeral 30 denotes an instruction for writing a numerical value -1 to the internal register D0 of the CPU, reference numeral 31 denotes an instruction for writing a numerical value 4000 to the internal register D1, and reference numeral 32 denotes a value stored in the internal register D0 and the internal register D1, respectively. An instruction to write to the A memory 26 and the constant parameter B memory 27 is an instruction to write information for permitting D / A output to the D / A output permission memory 23.

Next, the operation will be described. When the device 34, which is turned on once after the power is turned on, is turned on, the sequence processing unit 11 executes the commands 30, 31 and 32 of FIG. 3 and stores the numerical values in the constant parameter A memory 26 and the constant parameter B memory 27, respectively. 1, 4000 are written as constant parameter A and constant parameter B.
Thereafter, while the control start device 35 is ON, information for permitting the D / A output is written in the D / A output permission memory 23 by the instruction 33.

FIG. 4 is a flowchart of the processing executed by the processing unit 15 of FIG. In the figure, 40 is A in FIG.
A process for taking in the digital value converted by the / D conversion unit 17, a process 41 for writing the taken A / D converted value into the A / D converted value memory 20, and a process 42 for storing the constant parameter A memory 26 and the constant parameter B memory 27 A process for taking in the stored constant parameter A and the constant parameter B, a process 43 for performing an operation of y = Ax + B using the constant parameter A and the constant parameter B with an A / D converted value as x, and a process result 44 Is written to the operation result storage memory 22; 45 is the D / A output permission memory 2
A process of reading the contents of No. 3 and judging whether or not the contents are information permitting the D / A output, and a process 46 of setting the result y to the D / A conversion unit 19 as a value for analog output. It is.

The processing unit 15 of the analog input / output unit
Processing is performed according to the flowchart shown in FIG. First,
The processing unit 15 converts the analog input amount input to the analog input unit 18 by the processing 40, the processing 41, and the processing 42 into A
It is converted into a digital value by the / D conversion unit 17 and written into the A / D conversion value memory 20, and the constant parameter A and the constant parameter B are read from the constant parameter A memory 26 and the constant parameter B memory 27. take in. Next, the analog input amount x converted into the digital amount obtained by the process 40 in the process 43 is substituted into the function expression y = Ax + B to calculate the analog output amount y. Then, the value of y is stored in the calculation result storage memory 22 by the process 44.

Next, at step 45, it is determined whether or not the content stored in the D / A output permission memory 23 is information for permitting the D / A output. If not, the process returns to step 40, where D / A
If the information permits output, y of the operation result is output as an analog output amount through the D / A converter 19. According to the first embodiment, the processing time from the input to the output of the analog amount does not depend on the execution cycle of the sequence program, so that the processing time is prevented from increasing.

Embodiment 2 FIG. 5 is a diagram showing a relationship between an analog input amount and an output amount when control is performed by an analog input / output unit according to another embodiment of the present invention. In the figure, the horizontal axis represents the amount of analog input, the vertical axis represents the amount of analog output, and the number on each axis represents the amount of analog input or output on each axis indicating the positions of points A, B and C on the graph. Is a digitized value of these analog quantities.

FIG. 6 is a diagram showing a sequence program stored in the sequence program memory 12 of the CPU unit 10 of the PC. In the figure, 60 is a CPU
An instruction to write a numerical value 0 to the internal register D0 of the unit 10, an instruction to write a numerical value 4000 to the internal register D1, an instruction to write a numerical value 1000 to the internal register D2, an instruction to write a numerical value 2000 to the internal register D3, an instruction 64 Is an instruction to write a value 4000 to the internal register D4, 65 is an instruction to write a value 500 to the internal register D5, and 66 is a value stored in the internal register D5 from the internal register D0. Power 1 memory 29, analog input 2 memory 2a, analog output 2 memory 2b, analog input 3 memory 2c, analog output 3 memory 2
The instruction 67 is an instruction to write information for permitting D / A output in the D / A output permission memory 23. Note that the function formula calculating means is embodied by the processing unit 15.

Next, the operation will be described. The sequence processing unit 11 shown in FIG.
8 is turned on, the analog input amount 1 memory 28, the analog output amount 1 memory 29, the analog input amount 2 memory 2a, the analog output amount 2 memory 2
b, a predetermined numerical value is written in each of the analog input amount 3 memory 2c and the analog output amount 3 memory 2d. Here, the numerical value to be written in the analog input amount 1 memory 28 and the analog output amount 1 memory 29 is a value indicating the position of the point A in FIG. 5, and when the digital conversion value of the analog input amount is 0, the analog value of the digital value 4000 is obtained. Indicates that the output amount is output.

Similarly, the analog input amount 2 memory 2a and analog output amount 2 memory 2b, analog input amount 3 memory 2c, and analog output amount 3 memory 2d indicate the positions of points B and C on FIG. Analog input 1 memory 2
8, analog output 1 memory 29, analog input 2 memory 2a, analog output 2 memory 2b, analog input 3 memory 2c, and analog output 3 memory 2d
After the value is set, the sequence processing unit 11 writes information indicating permission of output from the analog input / output unit 14 to the D / A output permission memory 23 while the control start device 69 is ON.

FIG. 7 is a flowchart of the internal processing of the analog input / output unit. In the figure, 70 is a process for converting an analog input amount into a digital value, 71 is a process for writing the digital value converted by the process 70 into the A / D conversion value memory 20, 72 is an analog input amount 1 memory 28, an analog output amount 1 memory 29, analog input amount 2 memory 2a,
A process 72 takes in the values of the analog output amount 2 memory 2b, the analog input amount 3 memory 2c, and the analog output amount 3 memory 2d, and generates a function formula for calculating the analog output amount from the analog input amount. A process for substituting the digital value converted in the process 70 into the function formula generated in the step 70 to calculate a value for analog output, and a process 74 for storing the result calculated in the process 73 in the operation result storage memory 22
75 determines whether or not the content of the D / A output permission memory 23 is information for permitting the D / A output.
If not, the process returns to the process 70. If the information permits the D / A output, the process proceeds to the process 76. In the process 76, the result calculated in the process 73 is converted by the D / A converter 19 into an analog output amount. Processing.

The processing section 15 of the analog input / output unit 14 shown in FIG. 1 is processed according to the flowchart shown in FIG.
In a process 70, the analog amount input to the analog input unit 18 in FIG. 1 is converted into a digital value.
In the A / D conversion value memory 20 of FIG. In the process 72, the analog input amount 1 memory 28, analog output amount 1 memory 29, analog input amount 2 memory 2a, analog output amount 2 memory 2b, analog input amount 3 memory 2c, and analog output amount 3 memory 2d in FIG. Generate a function expression from the written value.

First, a linear equation is obtained from the analog input amount 1 memory 28 and the analog output amount 1 memory 29, and the analog input amount 2 memory 2a and the analog output amount 2 memory 2b. According to the sequence program of FIG. 6, the analog input amount 1 memory 28, the analog output amount 1 memory 29, the analog input amount 2 memory 2a, the analog output amount 2 memory 2b
Are written with numerical values 0, 4000, 1000, and 2000, respectively, so that y = (− 2) x + 4000 (function expression 1) is obtained from these numerical values. Next, analog input amount 2 memory 2a, analog output amount 2 memory 2b, analog input amount 3
Y = (− 0.5) x + 2500 (Functional Expression 2) is obtained from the numerical values written in the memory 2c and the analog output amount 3 memory 2d. In the functional expressions 1 and 2, x is a digital conversion value of an analog input amount, y is an operation result,
It is a digital value that is converted to an analog quantity.

Next, in a process 73, the analog input amount converted into the digital value obtained in the process 70 is substituted into the function formula generated in the process 72 to obtain an analog output amount. First,
The analog input amount converted into the digital value is compared with the value written in the analog input amount 2 memory 2a. If the analog input amount converted into the digital value is smaller than the value of the analog input amount 2 memory 2a, The operation is performed using the function expression 1, and in the case of more than that, the operation is performed using the function expression 2. In the process 74, the calculation result obtained in the process 73 is written in the calculation result storage memory 22. In the process 75, it is determined whether or not the information for permitting the D / A output is written in the D / A output permitting memory 23.
Proceeds to step 70 if not written. In the process 76, the result calculated in the process 73 is input to the D / A converter 19 in FIG. 1, converted into an analog amount, and output to the control target 1b via the analog output unit 1a. In this way, according to the second embodiment, it is possible to easily set the function formula indicating the relationship between the analog input amount and the analog output amount.

Embodiment 3 As in the first or second embodiment, the analog input / output unit 14 calculates the analog output amount from the analog input amount without depending on the sequence program of the PC,
When this is output, the analog output amount changes instantaneously from a state where there is no output to an output amount calculated from the analog input amount at the start such as when the power is turned on.
b may be impacted. The purpose of the third embodiment is to prevent such a sudden change in the analog output amount at the time of starting. FIG. 8 is a diagram showing a sequence program of the CPU unit of the PC according to the third embodiment of the present invention. In the figure, reference numeral 80 denotes an internal register D of the CPU.
An instruction to write a numerical value -1 to 0, an instruction to write a numerical value 4000 to the internal register D1 of the CPU, and an instruction 82 to store the numerical values stored in the internal register D0 and the internal register D1 in the constant parameter A memory 26 and the constant parameter B memory, respectively. 27, 83 is a command to write information for permitting D / A output in the D / A output permission memory 23, 84 is a command to turn on M0 while the operation result is output by the analog input / output unit 14, 85 Is an instruction to write information for switching the output to the output switching memory 25, 86 is an instruction to write an arbitrary value to be output as an analog output amount to the internal register D2, and 87 is a D / D for CPU for writing the value written to the internal register D2. This is an instruction to write to the A conversion value memory 21. Note that the selecting unit is embodied by the processing unit 15.

Next, the operation will be described. The sequence processing unit 11 determines that the device 88 that is turned on once after the power is turned on is
When N, the constants -1 and 4000 are written as constant parameters A and B in the constant parameter A memory 26 and the constant parameter B memory 27 according to the instructions 80, 81 and 82 of FIG. While 89 is ON, information for permitting D / A output is written in the D / A output permitting memory 23, and analog output is permitted.

Next, the instruction 85 controls whether the analog output is a value written by the sequence program or a value calculated in the analog input / output unit. That is, while the M0 signal is OFF, the output switching memory 25 is OFF (that is, information designating to output the value written by the sequence program is written in the output switching memory 25), and the instruction 86,
The value output as an analog quantity is written to the CPU D / A conversion memory 21 by the instruction 87. When the M0 signal is turned on by the automatic control start device 8a, the output switching memory 25 is turned on (that is, information designating to output the value calculated by the analog input / output unit 14 is written in the output switching memory 25). .

FIG. 9 is a flowchart of the processing executed by the processing unit 15 of FIG. In the figure, reference numeral 90 denotes a process for capturing a digital value converted by the A / D converter 21;
Reference numeral 91 denotes an A / D conversion value memory 2 for storing the fetched A / D conversion value.
0 is a process of writing data to the constant parameter A memory 26
And a process of taking in the constant parameter A and the constant parameter B stored in the constant parameter B memory 27. Reference numeral 93 substitutes the constant parameter A, the constant parameter B, and the value obtained by the A / D conversion into the function expression y = Ax + B. This is a process for obtaining a digital value y to be output as an analog quantity.

Reference numeral 94 denotes a process for writing the y obtained in the process 93 to the operation result storage memory 22, and reference numeral 95 reads the contents of the D / A output permission memory 23, and the read contents permit the D / A output. A process 96 for judging whether or not the information to be read out is performed. 96 reads out the content of the output switching memory 25 and determines whether the read out content is the information for outputting the value obtained in the process 94 or the CPU unit 10. To determine whether to output the value written in the D / A conversion value memory 21 for CPU from the CPU.
2 is a process of D / A converting the content of 2 and outputting it as an analog quantity.
/ A conversion and output as an analog quantity.

The processing section 15 of the analog input / output unit 14 of FIG. 1 is processed as shown in the flowchart of FIG. First, an analog amount input to the analog input unit 18 of FIG. 1 is converted into a digital value by the processing 90 and the processing 91 and written into the A / D conversion value memory 20. Next, processing 9
2, using the constant parameter A and the constant parameter B set in the constant parameter A memory 26 and the constant parameter B memory 27 by the processing 93 and the processing 94, the function formula y
= Ax + B is substituted for the analog input amount converted into the digital value, and the result y is written to the operation result storage memory 22. In the process 95, the content of the D / A output permission memory 23 is
It is determined whether or not the information permits the A output. If not, the process returns to the process 90 without outputting the analog amount, but proceeds to the process 96 if the information permits the D / A output.

In step 96, the contents of the output switching memory 25 are read. If the instruction 85 in FIG. 8 indicates that the output switching memory 25 performs D / A conversion on the contents of the operation result storage memory 22 and outputs the result, the process proceeds to step 97, where the output switching memory 25 sets the CPU D / A. If the information indicates that the content of the conversion value memory is to be D / A converted and output, the process 98
Proceed to. In step 97, the value calculated in step 93 and stored in the operation result storage memory 22 is D / A converted and output as an analog quantity. In the process 98, the values written by the instructions 86 and 87 in FIG. 8 are D / A converted and output as analog quantities. According to the third embodiment, the CPU D
After the analog amount based on the predetermined digital amount stored in the / A conversion value memory is output in advance, the analog amount based on the contents of the operation result storage memory 22 can be output. Etc. can be prevented.

Embodiment 4 FIG. Next, still another embodiment of the present invention will be described.
FIG. 10 is a diagram showing the internal configuration of the A / D converter 17 in FIG. In the figure, reference numeral 100 denotes a V / F converter for converting an analog input voltage into a pulse train having a frequency proportional to the magnitude of the analog input voltage, and 101 denotes a pulse output from the V / F converter 100 within a predetermined time. It is a counter for counting. FIG. 11 is a diagram showing the internal configuration of the D / A converter 19 in FIG. In the figure, reference numeral 110 denotes a gate circuit which outputs an input constant voltage amount while a gate control signal is ON. An integration circuit 111 integrates a constant voltage amount (pulse), which is a signal output from the gate circuit 110, and is input at regular intervals, and converts it into a voltage amount.

FIG. 12 is a diagram showing the configuration of the offset / gain storage section 11c of FIG. In the drawing, reference numeral 120 denotes a first A / D offset value memory storing a first A / D conversion offset value, 121 denotes a first A / D gain value memory storing a first A / D gain value, and 122 denotes a second A / D. A second A / D offset value memory for storing a conversion offset value, a second A / D gain value memory for storing a second A / D conversion gain value, and a second A / D gain value memory for storing a first D / A conversion offset value. 1D / A offset value memory,
A first D / A 125 stores a first D / A conversion gain value.
A gain value storage memory 126 is a second D / A offset value memory for storing a second D / A conversion offset value,
27 is a second D in which the second D / A conversion offset value is stored
/ A gain value memory. Note that the first A / D offset value memory 120, the first A / D gain value memory 121,
A first D / A offset value memory 124;
/ A gain value storage memory 125 constitutes one storage means, and includes a second A / D offset value memory 122 and a second
A / D gain value memory 123, second D / A offset value memory 126, and second D / A gain value memory 12
7 constitute one storage means.

FIG. 13 is a diagram showing a relationship between an analog amount and a digital value when 0-10 V is a voltage defining an offset value and a gain value, and 4-20 mA is a current defining an offset value and a gain value. is there. The offset value is an analog amount when the digital value is 0, and the gain value is an analog amount when the digital value is 4000.

Next, an operation for setting an offset value and a gain value in two cases of 0-10 V and 4-20 mA will be described. First, the A / D converter 17
The setting of the offset value and the gain value will be described. A voltage of 0 V, 1
0 V, a current of 4 mA, and a current of 20 mA are sequentially input. The input voltage value is input to the V / F converter 100 in FIG. Then, a pulse having a frequency proportional to the input voltage value is output to the V / F converter 1.
00 and is counted by the counter 101. 4 mA, 20 mA input to the analog input unit 18
Are converted into pulses having frequencies corresponding to the voltage values of 2 V and 10 V, respectively, and then input to the counter 101, where the number of pulses is counted. Then, the value of 0 V converted into the number of pulses is stored in the first A / D offset value memory 120 as the first offset value, and the value of 1 V converted into the number of pulses is stored.
The value of 0 V is stored in the first A / D gain value memory 121 as a first gain value, and the value of 4 mA is stored in the second A / D offset value memory 122 as a second offset value.
The value of 20 mA is stored in the second A / D gain value memory 123 as a second gain value.

Next, setting of the offset / gain value of the D / A converter 19 will be described. First, the processing unit 15 shown in FIG.
Indicates that the output voltage value of the analog output unit 1a is 0 V, which is the first offset value, based on a command from the CPU unit 10.
Thus, the pulse width of a pulse having a constant period inputted as a gate control signal of the gate circuit 110 of FIG. 11 is adjusted. Then, the digital value indicating the pulse width at that time is stored in the first D / A offset value memory 124 in FIG. Similarly, voltage 1 as the first D / A gain value
The digital value indicating the pulse width of the gate control signal that outputs 0 V, 4 mA as the second D / A offset value, and 20 mA as the second D / A gain value is stored in the first D / A gain value memory 125 in FIG. 2nd D / A
They are stored in the offset value memory 126 and the second D / A gain value memory 127, respectively.

Next, means for selecting an offset value and a gain value will be described. The CPU unit 10 of the PC stores information indicating whether to select the first offset / gain value or the second offset / gain value in the offset / gain selection memory 24 shown in FIG. 2 according to the sequence program. Note that the first offset / gain value is the first A / D offset value, the first A / D gain value, the first D / D
An A offset value and a first D / A gain value, and the second offset / gain value is a second A / D offset value, a second A / D gain value, a second D / A offset value, and a second D / A gain. It shall consist of values. on the other hand,
The processing unit 15 of the analog input / output unit 14 in FIG.
One of the offset / gain value and the second offset / gain value is read from the offset / gain storage unit 11c shown in FIG. 12, the read offset value is a digital value 0, and the read gain value is a digital value. 40
A / A
Execute D conversion and D / A conversion. According to the fourth embodiment, the offset value and the gain value can be easily set or changed as described above.

Embodiment 5 FIG. FIG. 14 is a diagram showing a system configuration according to still another embodiment of the present invention. In the figure, 140 is the PC C
A sequence processing unit of the PU unit; 141, a sequence program memory; 142, an interface unit with the analog input / output unit; 143, an interface unit;
4 is a processing unit of the analog input / output unit, 145 is a CPU
A dual port memory 146 for exchanging data with the unit 146 is an A / D conversion and analog input unit.
Denotes a D / A conversion and analog output unit, 148 denotes a constant voltage / current power supply device, and 149 denotes a voltmeter. The interface unit 143 is provided for transmitting and receiving signals to and from the constant voltage / current power supply device and the volt / ammeter. The voltage reading means and the current reading means are constituted by a voltage / ammeter 149 and an interface unit 143, and the constant voltage power supply and the constant current power supply are constituted by a constant voltage / current power supply device 148 and the interface unit 143. The writing means is embodied by the processing unit 144.

FIG. 15 shows the sequence program memory 14.
FIG. 2 is a diagram showing a sequence program stored in the first program.
In the figure, reference numeral 150 denotes the interface unit 143 of FIG.
2. A command 151 for outputting a voltage of 0 V to the constant voltage / current power supply device through the A / D / D / A selection memory 2e of FIG.
FF is an instruction for indicating that the offset / gain setting of the A / D conversion unit is performed.
This is a command to turn on the offset command memory 2f in FIG. 2 when a voltage of 0 V is applied to the / D converter 146. As will be described later, when the offset command memory 2f is turned on,
The conversion output of the A / D converter at this time is stored as an offset value. The command 150, the command 151, and the command 152 are executed when the offset setting command device of the A / D converter is turned on.

Reference numeral 153 denotes an instruction to output a voltage of 10 V to the constant voltage / current power supply 148, and reference numeral 154 denotes A / D, D of FIG.
A command to turn off the / A selection memory 2e.
When the D / D / A selection memory 2e is turned off, the offset / gain setting of the A / D converter is selected. Reference numeral 155 denotes a command for turning on the gain command memory 2g in FIG. 2 when a voltage of 10 V is applied to the A / D converter 146. When the gain command memory 2g is turned on, the A / D The output of the D converter is stored as a gain value. The instruction 153, the instruction 154, and the instruction 15
Step 5 is executed when the A / D gain setting command device is turned on.

Reference numeral 156 denotes an instruction to take in a voltage value from the voltmeter 149, and reference numeral 157 denotes an instruction to turn on the A / D and D / A selection memory 2e in FIG. When turned ON, the offset / gain setting of the D / A converter is selected. 158 indicates that the taken voltage value is 0 V
At this time, this is a command to turn on the output down command memory 2i in FIG. 2. When the output down command memory 2i is turned on, the voltage value output from the D / A converter decreases as described later. Reference numeral 159 denotes a command for turning on the output-up command memory 2h when the fetched voltage value is 0 V or less. When the output-up command memory 2h is turned on, the output voltage value from the D / A converter increases as described later. . Reference numeral 15a denotes a command for turning on the offset command memory 2f in FIG. 2 when the taken voltage value is 0 V. When the offset command memory 2f is turned on, the D / A at that time will be described later.
The input value of the conversion unit is stored as an offset value. Note that the instruction 156, the instruction 157, the instruction 158, the instruction 15
9 and the command 15a are executed when the D / A offset setting command device is turned on.

15b is a command for taking in the voltage value of the voltmeter 149 in FIG. 14, and 15c is a command for turning on the A / D and D / A selection memory 2e in FIG. When the memory 2e is turned on, the offset / gain setting of the D / A converter is selected. 15d is a command to turn on the output down command memory 2i in FIG. 2 when the taken voltage value is 10 V or more,
When it becomes N, the voltage value output from the D / A conversion unit decreases as described later. 15e is the fetched voltage value of 10V
This is a command to turn on the output-up command memory 2h in the following cases. When the output-up command memory 2h is turned on, the output voltage value from the D / A converter increases as described later.
15f is a command to turn on the gain command memory 2g in FIG. 2 when the taken voltage value is 10V, and when the gain command memory 2g is turned on, the D / D
The input value of the A conversion unit is stored as a gain value. In addition,
The command 15b, the command 15c, the command 15d, the command 15e, and the command 15f have the D / A gain setting command device of O
Executed when N is reached.

FIGS. 16 and 17 show the processing unit 1 of FIG.
It is a flowchart which shows operation | movement of 44. In FIG. 16, 1
If the A / D and D / A selection memory 2e in FIG. 2 is OFF, the process proceeds to a process of setting an offset value and a gain value of the A / D converter. Processing for setting the value and gain value,
If the offset command memory 2f in FIG. 2 is ON, the process proceeds to the process 162. If the offset command memory 2f is OFF, the process proceeds to the process 163. The process 162 is a process of fetching and storing an offset value from the A / D converter. Gain command memory 2g
If is ON, the process proceeds to process 164, and if OFF, the process returns to process 160. 164 is a process that fetches and stores the gain value from the A / D converter and returns to process 160.

In FIG. 17, if the output up command memory 2h of FIG.
If it is FF, the process proceeds to process 167; 166, the process of increasing the output value to the D / A converter; 167, the process proceeds to process 168 if the output down command memory 2i in FIG. 2 is ON; Processing to proceed to processing 169, 168 is D
The process 169 for lowering the output value to the / A converter is shown in FIG.
If the offset command memory 2f is ON, the process 16a
If it is OFF, the process proceeds to process 16b, 16a
Is a process of storing the input value of the D / A converter as an offset value, 16b is a process of proceeding to a process 16c if the gain command memory 2g in FIG. 2 is ON, and a process of returning to a process 160 if the gain command memory 2g is OFF. The process returns to the process 160 after storing the input value of the A conversion unit as the gain value.

Next, the operation will be described. The processing unit 144 of FIG. 14 performs the processing shown in the flowcharts of FIGS. 16 and 17, and is controlled by the sequence program of FIG.
D, D / A selection memory 2e, offset command memory 2
f, gain command memory 2g, output up command memory 2
h and the state of the output down command memory 2i.
The offset / gain value is fetched and stored from the / D conversion unit, and the output value to the D / A conversion unit is increased or decreased, and the offset value and the gain value are stored after the offset / gain value is adjusted. The values stored as the offset and gain values are the value counted by the counter 101 in FIG. 10 when the voltage of 0 V is supplied from the constant voltage current device in the A / D converter, and the voltage of 10 V. This is a value counted by the counter 101 at times. Also, D
In the / A converter, a digital value indicating the pulse width of the gate control signal of gate circuit 110 when voltage 0V is output, and the pulse width of the gate control signal of gate circuit 110 when voltage 10V is output Is a digital value indicating According to the fifth embodiment, the offset value or the gain value can be easily set in this manner.

[0063]

As described above, the sequence program
Installed in the main controller that operates
Analog signal processor for programmable controller
Analog input that is input from the controlled object.
A / D conversion means for converting a force signal into a digital signal,
The conversion output of the A / D conversion means
A predetermined function formula based on the instruction information from the controller
Calculation means for performing more calculations, and calculation based on the calculation means
Calculation output or programmable controller body
Means for selecting one of the command values from
Based on the calculation output or command value selected by the selection means.
Output means for outputting an analog output to the control object.
So that the analog output can be switched.
For example, when the output changes suddenly at the time of startup at power-on, etc.
Impact on the control object can be prevented.

The offset value of the A / D conversion and the gain
In value, D / A conversion offset value and gain value
It has a plurality of storage means for storing, from this plurality of storage means
Offset value based on the storage content of the selected storage means
Set the offset value and gain value.
It is possible to easily set or change the in value.

The analog input from the control object
A / D conversion means for converting an input signal into a digital signal,
Of performing a predetermined operation on the conversion output of the A / D conversion means.
Calculation means, analog output based on the calculation output of the calculation means
Output means for outputting an image to a control object
In the analog signal processor for logic controllers, flop
D / A by command from the programmable controller
Voltage reading means or a voltage reading means capable of reading the conversion output of the conversion means.
Flow reading means and commands of the programmable controller body
Outputs a predetermined voltage or current value based on the
Constant voltage power supply or constant current for inputting force to A / D conversion means
Make sure that the power supply and the constant voltage or constant current
Or the conversion output of the A / D conversion means when the current value is output
As an A / D conversion offset value or gain value
Means, and a programmable controller book
Also read output of voltage reading means or current reading means from the body
Command to increase or decrease the input value to the D / A conversion means
And a predetermined voltage value by the voltage reading means or the current reading means.
Alternatively, the input value when a predetermined current value is read is changed by D / A conversion.
Write to the storage means as a new offset value or gain value
Offset means or gay
Value can be easily set.

[Brief description of the drawings]

FIG. 1 is a functional block diagram showing an analog input / output unit and a CPU unit of a PC according to the present invention.

FIG. 2 is a memory internal configuration diagram of a dual port memory in FIG. 1;

FIG. 3 is a diagram showing a sequence program for controlling an analog input / output unit according to the first embodiment of the present invention.

FIG. 4 is a flowchart showing internal processing of an analog input / output unit according to Embodiment 1 of the present invention.

FIG. 5 is a diagram showing a relationship between an analog input amount and an output amount when controlled by an analog input / output unit according to Embodiment 2 of the present invention.

FIG. 6 is a diagram showing a sequence program for controlling an analog input / output unit according to Embodiment 2 of the present invention.

FIG. 7 is a flowchart showing internal processing of an analog input / output unit according to Embodiment 2 of the present invention.

FIG. 8 is a diagram showing a sequence program for controlling an analog input / output unit according to Embodiment 3 of the present invention.

FIG. 9 is a flowchart showing internal processing of an analog input / output unit according to Embodiment 3 of the present invention.

FIG. 10 is a diagram showing an internal configuration of an A / D converter of an analog input / output unit according to Embodiment 4 of the present invention.

FIG. 11 is a diagram showing an internal configuration of a D / A converter of an analog input / output unit according to Embodiment 4 of the present invention.

FIG. 12 is a diagram showing a configuration of a memory for storing an offset value and a gain value of an analog input / output unit according to Embodiment 4 of the present invention.

FIG. 13 is a diagram showing a relationship between an analog amount and a digital value of an analog input / output unit according to Embodiment 4 of the present invention.

FIG. 14 shows an analog input / output unit for automatically adjusting and setting an offset value and a gain value of an analog input / output unit according to Embodiment 5 of the present invention, and a CPU of a PC.
It is a functional block diagram showing a unit.

FIG. 15 is a diagram showing a sequence program for automatically adjusting and setting an offset value and a gain value of an analog input / output unit according to Embodiment 5 of the present invention.

FIG. 16 is a flowchart showing internal processing of an analog input / output unit according to Embodiment 5 of the present invention.

FIG. 17 is a flowchart showing internal processing of an analog input / output unit according to Embodiment 5 of the present invention.

FIG. 18 shows a conventional analog input / output unit and a PC.
FIG. 4 is a functional block diagram showing a CPU unit of FIG.

FIG. 19 is a diagram showing a sequence program for controlling a conventional analog input / output unit.

[Explanation of symbols]

10 CPU unit of PC, 11 sequence processing unit, 12 sequence program memory, 13 interface unit, 14 analog input / output unit unit, 15
Processing unit of analog input / output unit, 16 dual port memory, 17 A / D conversion unit, 18 analog input unit,
19 D / A conversion unit, 1a analog output unit, 1b control object, 1c offset / gain storage unit, 20A
/ D conversion value memory, 21 CPU D / A conversion value memory, 22 operation result storage memory, 23 D / A output permission memory, 24 offset / gain selection memory, 25
Output switching memory, 26 constant parameter A memory,
27 constant parameter B memory, 28 analog input amount 1 memory, 29 analog output amount 1 memory, 2a analog input amount 2 memory, 2b analog output amount 2 memory,
2c Analog input amount 3 memory, 2d Analog output amount 3 memory, 2e A / D, D / A selection memory, 2f Offset setting instruction memory, 2g Gain setting instruction memory, 2h Output up instruction memory, 2i Output down instruction memory, 11c Offset / gain storage unit, 100
V / F converter, 101 counter, 111 gate circuit, 112 integrator, 120 first A / D offset value memory, 121 first A / D gain value memory, 122
2nd A / D offset value memory, 123 2nd A / D gain value memory, 124 1st D / A offset value memory, 125 1st D / A gain value memory, 126 2nd
D / A offset value memory, 127 second D / A gain value memory, 140 sequence processing unit, 141 sequence program memory, 142 interface unit, 1
43 interface section, 144 analog input / output unit processing section, 145 dual port memory, 146
A / D conversion unit, 147 D / A conversion unit, 148 constant voltage / current power supply device, 149 voltage / ammeter, 170 PC CPU unit, 171 sequence processing unit, 172
Sequence program memory, 173 interface section, 174 analog input / output unit section, 175 processing section of analog input / output unit, 176 A / D conversion value memory section, 177 D / A conversion value memory section, 178 A /
D conversion section, 179 analog input section, 17a D / A conversion section, 17b analog output section, 17c control object,
17d switch section.

Claims (3)

(57) [Claims] An analog signal processing device for a programmable controller provided in a programmable controller main body that operates based on a sequence program, and converts an analog input signal input from a control target into a digital signal. A / D conversion means, operation means for performing an operation on the conversion output of the A / D conversion means by a predetermined function formula based on instruction information from the programmable controller main body, and operation output calculated based on the operation means Alternatively, there is provided a selecting means for selecting one of the command values from the programmable controller main body, and an output means for outputting an analog output based on the arithmetic output or the command value selected by the selecting means to the control object. Analog signal processor for programmable controllers. 2. An offset value and a gain for A / D conversion.
Stores the offset value and gain value of D / A conversion
And a plurality of storage means for performing selection from the plurality of storage means.
Offset value based on the stored contents of the storage means
And setting a gain value.
Analog signal processing for programmable controller as described
apparatus. 3. An analog input input from an object to be controlled.
A / D conversion means for converting a signal into a digital signal;
An operator who performs a predetermined operation on the conversion output of the / D conversion means
The analog output based on the operation output of this operation means
Output means for outputting to an object to be controlled
In analog signal processors for portable controllers,
D / A by command from the programmable controller
Voltage reading means or a voltage reading means capable of reading the conversion output of the conversion means.
Flow reading means and the programmable controller main body.
Outputs a predetermined voltage or current value based on a command,
A constant voltage power supply or a constant voltage
Current power supply and the above constant voltage power supply or constant current power supply
The above A / D converter when a voltage value or a current value is output
A / D conversion offset value or gain
Write to the storage means as a value and
Voltage reading means or current reading from the controller
Input to the D / A conversion means based on the read output of the
A command to increase or decrease the force value is issued, and the voltage reading means or
Predetermined voltage value or predetermined current value is read by current reading means
The above input value at the time of the
Writing means for writing to the storage means as a gain value or a gain value;
Programmable controller characterized by having
Analog signal processing device.