JP2001249708A - Programmable controller - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To provide a high-function programmable controller that realizes high functionality by a counter module and does not increase the cost. SOLUTION: A CPU module 6 and a pulse signal 13 are provided.
Function programmable controller 4 provided with a counter module 1 which is a high function module for counting
, The counter module includes an interrupt processing unit 12 that counts by an interrupt due to a pulse signal, a cycle measurement unit 19 that measures the cycle of the pulse signal, and a switching unit 23. Further, the interrupt processing unit includes a plurality of different frequencies. (1KHz, 5KHz, 10KHz, 20KH
count processing execution unit 1 for counting pulse signals in z)
5, 16, 17 and 18, and selects and switches the count processing execution section based on the cycle of the pulse signal measured by the cycle measurement section 19, and executes another processing having a different processing time.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a programmable controller which is used in various kinds of control such as positioning control and can change the contents of control by changing a program thereof. The present invention relates to a programmable controller capable of achieving functions.

[0002]

2. Description of the Related Art Programmable controllers whose control contents can be changed are already widely used in control devices.
Among such conventional programmable controllers, a module type programmable controller will be described with reference to FIGS.

FIG. 6 shows an example of a configuration of a positioning control device using a programmable controller.
As is clear from the figure, the module type programmable controller 4 basically includes a power supply module 5 and a CPU module 6 for performing arithmetic control. It is composed of modules, high-performance modules and the like. In addition,
The high function module is a module for connecting to an external special device, and is provided when a high function is required for the programmable controller. As one of such high-performance modules, there is a so-called counter module 1.

The counter module 1 controls the positioning of the control target 3 in a control device to which the programmable controller 4 is applied.

In such a control device, in order to execute the positioning control, it is usually necessary for the CPU module 6 to detect and grasp the position of the control target 3. In order to achieve this object, generally, an encoder 2 that rotates with the movement of the control target 3 is provided, and the encoder 2 outputs a pulse corresponding to the number of rotations. That is, the count value of the pulse output from the encoder 2 becomes data indicating the position of the control target 3. Then, based on the position detection data, the programmable controller 4 can control the position of the control target 3 while detecting and grasping the position.

As described above, the basic function of the counter module 1 in the programmable controller 4 is to count the pulses 7 from the encoder 2 and pass this information (count value) to the CPU module 6 constituting the basic part of the controller. That is.

However, the above counter module 1
Is not necessarily limited to the basic function described above. For example, if the function is responded to an external data input, and the data is transferred to the CPU module 6 every time to perform the calculation and control, If the response speed is too slow, such a calculation function can be handled by the counter module 1. In such a case, the counter module 1 needs to have a high function capable of performing the high-speed response control. Therefore, conventionally, the price has been reduced by employing a microcomputer.

FIG. 7 shows an example of a high-performance module that is used as the counter module 1 in the programmable controller according to the related art and that is configured by employing the microcomputer 11.

In the high-performance module having the microcomputer 11, the input count pulse 13
Is input to the microcomputer 11, the process 12 is started in the form of an interrupt, and a predetermined count process 15 is generally executed.

However, in such a configuration, such interrupt processing must be set to the maximum expected at the frequency of the count pulse 13 (for example, 2
0 kHz).

This will be described with reference to FIG. 8 showing the timing of the counting process in the counter module 1 constituted by the microcomputer. In FIG. 8, every time the rising edge of the count pulse 13 is input, the microcomputer Is interrupted, and the counting process is executed. Note that this counting process is realized by executing a process of adding 1 or subtracting 1 in accordance with an interrupt process.

As is apparent from this figure, for example, when the moving speed of the control target 3 is accelerated, the frequency of the count pulse 13 naturally increases, and the period between the current pulse and the next pulse is increased. Be shorter. Therefore, for example, if the period between the pulses is shorter than the time of the interrupt processing, a problem that a part of the count pulse 13 is omitted from the count (see reference numeral 10 in the drawing) occurs.

Therefore, in the above-described conventional programmable controller, the counter module 1 composed of a microcomputer must set the count frequency related to the counter processing to the maximum (for example, 20 KHz) despite its capability. Therefore, the function for executing other processing is limited accordingly.

[0014]

That is, the function of the counter module is to execute only the count function by setting the countable pulse frequency to the maximum.
Other functions were fixedly set as restricted functions, which were suppressed accordingly.

Therefore, in the programmable controller having the high-performance (counter) module according to the prior art, in order to further improve the function of the counter module in which the countable frequency is set to the maximum as described above, the count is further increased. This has to be dealt with by adding hardware of the unit or by adopting a high-speed microcomputer. Therefore, there is a problem that this cannot be realized without further increasing the cost.

Accordingly, an object of the present invention is to provide a high-performance module that has already been provided without additional cost, such as adding hardware or employing a high-speed microcomputer, in view of the above-mentioned problems in the prior art. It is an object of the present invention to provide a novel programmable controller capable of realizing a high function of a certain counter module.

[0017]

According to the present invention, there is provided, in accordance with the present invention, an arithmetic processing unit for arithmetically processing an external input signal, and further comprising a pulse signal of the external input signal. In a programmable controller provided with a high-performance module comprising a second arithmetic processing unit, the second arithmetic processing unit may perform an interrupt process for counting a pulse signal by an interrupt from the external pulse signal. Unit, a period measuring unit that measures the period of the external pulse signal, and a switching unit, further, the interrupt processing unit has a count processing execution unit that counts the pulse signal at a plurality of different frequencies Thus, a plurality of counts of the interrupt processing unit are performed based on the cycle of the pulse signal measured by the cycle measuring unit. Switching from management execution unit selects one of the count processing execution unit, a programmable controller configured to different from the process is performed with the processing time corresponding to the plurality of count processing execution section is provided.

According to the present invention, the second arithmetic processing unit further includes means for transferring the frequency of the external pulse signal measured and calculated by the cycle measuring unit to the arithmetic processing unit. It is configured such that the selection of the switching unit is automatically performed by the measurement signal of the period measurement unit, or the selection of the switching unit is manually performed.

[0019]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

FIG. 6 again shows a so-called positioning control device that employs the programmable controller 4 according to the embodiment of the present invention, and in particular controls the position of the control target 3. That is, the position of the control target 3 is converted into a pulse signal 7 by the encoder 2 and input to the programmable controller 4, so that the programmable controller 4
While detecting and grasping the position, the position can be controlled with high accuracy.

In the programmable controller 4 according to the present invention, as is apparent from FIG.
Similarly to the above-mentioned conventional technology, the power supply module 5 and the CPU module 6 for performing arithmetic control are provided, and the pulse signal 7 from the encoder 2 is counted. A so-called counter module 1 is provided as a high-performance module for achieving the function of passing a value).

FIG. 1 shows a microcomputer 11 constituting the counter module 1 as a high-performance module, together with a count input pulse 13 from the encoder 2.
Details of 1 are indicated by its functional blocks. In this figure, reference numeral 12 indicates an interrupt routine (interrupt processing unit), and reference numerals 15, 16, 17, and 18 are provided in the interrupt processing unit 12 and classified according to frequency bands of input count pulses. Four modes (1KHz,
5 KHz, 10 KHz, 20 KHz), reference numeral 19 denotes a period measuring unit, reference numeral 20 denotes a register unit, reference numeral 21 denotes a maximum peak frequency register unit, reference numeral 22 denotes a mode manual operation unit, and reference numeral 23 denotes a switching unit. Is shown.

When the count pulse 13 from the encoder 2 is input to the microcomputer 11 constituting the counter module 1 having such a configuration, the count pulse 13 is input to the microcomputer 11, thereby entering an interrupt processing routine 12.

At the same time as the interrupt processing, the microcomputer 11 measures the cycle of the input count pulse 13 by the cycle measuring unit 19. In the interrupt routine 12 that has been activated as described above, a plurality of different modes (four in this example) that can be processed for each frequency of the count pulse 13 are prepared. Therefore, the microcomputer 11 obtains the frequency based on the data measured by the period measuring unit (frequency = 1).
/ Cycle), and based on this data, which mode function is to be selected is determined, and is switched by the switching unit 23.

In the above-described embodiment, the manual operation unit 22 is further provided, whereby the switching of the switching unit 23 is automatically performed by the microcomputer 11 as described above, and The manual operation unit 22 allows the operator to perform the operation manually.

The above four modes 15, 16, 1
7 and 18 are classified according to the frequency band of the input count pulse 13. According to this classification, in the high frequency mode 15 (20 KHz), the count processing time is short, and therefore, it is impossible to execute many other processings in the count processing time. Becomes smaller. On the other hand, in the mode 18 (1 KHz) whose frequency is low, the count processing time is long, and in this count processing period, many other processes can be executed correspondingly, and the function can be improved. It becomes possible.

On the other hand, the cycle measuring section 19 for measuring the cycle of the input count pulse 13 not only switches the interrupt processing modes 15, 16, 17, and 18 but also stores the obtained frequency data in the register 20. To the CPU module 6 via the
The module 6 can monitor not only the frequency at which the count pulse 13 is currently counted, but also the maximum peak frequency register 2 provided to hold the peak value of the maximum frequency.
By storing it in 1, it can be determined whether or not the count pulse 13 has not been missed.

Next, FIG. 2 shows a specific method for the switching unit 23 for switching to each of the processing modes 15, 16, 17, and 18 described above. The count processing units 15, 16, 17, and 18 in each mode in this example each store a program to be processed in a memory and have a respective start address.

Now, when the count pulse 13 is input and the interrupt processing is started by this, a jump is made to a predetermined address 25, and the instruction stored at this address is executed. The instruction stored at address 25 is
It further includes a command to jump to another address 26, and the address to which the jump is made is input to this address 26. For example, in this example, the CPU jumps to the address "IJKL" and executes the processing mode 17 stored therein. Alternatively, the jump destination address input to the address 26 is replaced with the above-mentioned “IJKL” address, for example, “AJL”.
If preset to "BCD", "EFGH" or "MNOP", it is possible to switch to another mode and execute.

That is, by appropriately setting the address 26 corresponding to the mode determined by the cycle measuring unit 19,
It is possible to lead to a mode to be executed in accordance with the frequency of the input count pulse 13 like a pointer on a railway line.

Next, an example of the execution function in the counting process described above will be described with reference to FIG. In FIG. 3, the count elapsed value is shown in the vertical direction, and the time is shown in the horizontal direction. Then, as apparent from the figure, the four set values 28 (1 KHz), 29 (5 KHz), 30 (1 KHz)
0 KHz) and 31 (20 KHz) are set.

According to this, the microcomputer 11 determines that the count elapsed value 27 has four set values 28,
Equal (=) for 29, 30, and 31, respectively
Is greater than or less than (>, <)
Is always transmitted to the CPU 6 and, if necessary, output to the outside as an output signal, and based on this output signal, the load of an external motor or the like can be stopped. Processing for comparing these set values with the elapsed count value requires time, and the processing time for that is proportional to the number of the set values. That is, advanced processing requires a longer processing time.

Therefore, in the present invention, for example, the four types of processing modes 15, 16, 17, 1 shown in FIG.
8, the processing contents are set as follows.

That is, in the processing mode 18, the comparison processing of the count elapsed value with respect to the four set values is executed, and in the processing mode 17, the comparison processing of the count elapsed value with the two set values is executed. Then, the comparison process of the count elapsed value with respect to one set value is executed,
Then, in the processing mode 15, it is set so that the above-described comparison processing is not performed. That is, for each processing mode,
Processing contents with different processing times are assigned,
The function differs depending on the processing content. In other words, the longer the processing time, the higher the function, while the shorter the processing time, the lower the function, which is the difference between the functions. Note that the enhancement of the functions described here is one example, and it goes without saying that other functions may be used.

The selected processing mode 1
5, 16, 17, and 18 are always sent to the CPU 6, so that the microcomputer 11
It is possible to always determine which information in the above processing contents is invalid.

Next, an example of a period measuring method in the period detecting section 19 of the count pulse of FIG. 1 will be described with reference to FIG.
And FIG. Generally, as shown in FIG. 4, a general-purpose microcomputer is provided with a free-running counter 32 for constantly counting a system clock required for the operation of the microcomputer. This counter value can be converted into time by multiplying it by the clock cycle.

Therefore, the microcomputer 11 executes an interrupt process every time the count pulse 13 is input. Therefore, the cycle of the count pulse 13 is the time from the start of the interrupt by the previous count pulse 13 to the start of the interrupt by the current count pulse 13. Therefore, in this interrupt processing, the following calculation is executed in the cycle measurement processing 34 during the interrupt processing as shown in FIG.

(Cycle) = (previous free running counter value) − (current free running counter value)

By multiplying the obtained cycle by the known clock cycle, the cycle time of the count input pulse is obtained, and the frequency can be calculated from its reciprocal.

As described above, according to the microcomputer 11 which is a high-performance module (counter module) which constitutes a part of the programmable controller 4 according to the present invention, as in the above-described prior art, Without increasing the cost by adding hardware or employing a high-speed microcomputer, that is, the lower the count pulse 13 input from the outside, the lower the count pulse 13
Count pulse (interrupt) for counting data
By increasing the period, many other counting processes can be executed during this period, and the function can be improved.

Accordingly, the cycle of the currently input count pulse is measured, and the mode is automatically switched to a function of a mode corresponding to the measured data, so that the maximum function can be obtained when the count pulse is at a low speed.

[0042]

As is clear from the above detailed description, according to the present invention, the cost is increased by realizing other functions with the counter module set to the maximum countable frequency. Without this, an excellent effect that it is possible to realize a more advanced function of the programmable controller is exhibited.

[Brief description of the drawings]

FIG. 1 is a functional block diagram illustrating details of a counter module which is a feature of a programmable controller according to the present invention.

FIG. 2 is a diagram showing a specific method of a switching unit for switching to each processing mode in the counter module.

FIG. 3 is an explanatory diagram showing an example of an execution function in a count process in the counter module.

FIG. 4 is a diagram showing an example of a period measuring method in the period detecting section of the count pulse.

FIG. 5 is also a flowchart showing an example of a cycle measuring method in the count pulse cycle detector.

FIG. 6 is a block diagram showing a schematic configuration of a positioning control device to which a programmable controller according to the present invention or the prior art is applied.

FIG. 7 is a functional block diagram illustrating details of a counter module of a programmable controller according to the related art.

FIG. 8 is a diagram showing the timing of a count process in the counter module according to the conventional technique.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Counter module 2 Encoder 3 Control object 4 Programmable controller 6 CPU module 13 Count pulse 11 Microcomputer (counter module) 12 Interrupt processing part 15, 16, 17, 18 Count processing 19 Period detection part 20 Count pulse frequency register part 21 Maximum peak Frequency holding register section 22 Mode manual setting section 23 Function mode changeover switch section

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5B098 AA05 BA06 BB11 EE01 EE06 GA01 5H220 BB03 CC03 CX03 CX05 EE09 EE12 EE13 JJ02 JJ16 JJ59 9A001 BB01 BB02

Claims (4)

[Claims] A high-performance processing unit comprising an arithmetic processing unit for arithmetically processing an external input signal, and further comprising a second arithmetic processing unit for counting a pulse signal of the external input signal. In a programmable controller including a module, the second arithmetic processing unit includes an interrupt processing unit that counts a pulse signal by an interrupt due to the external pulse signal, and a cycle measuring unit that measures a cycle of the external pulse signal. And a switching unit, and the interrupt processing unit further includes a count processing execution unit that counts pulse signals at a plurality of different frequencies, and thus the cycle of the pulse signal measured by the cycle measurement unit. Based on, select and switch one count processing execution unit from the plurality of count processing execution units of the interrupt processing unit, A programmable controller characterized in that another processing with a different processing time corresponding to the plurality of count processing execution units is executed. 2. The programmable controller according to claim 1, wherein the second arithmetic processing unit further calculates a frequency of the external pulse signal measured and calculated by the cycle measuring unit. A programmable controller, comprising: means for transferring data to a programmable controller. 3. The programmable controller according to claim 1, wherein the second arithmetic processing unit is configured to automatically select the switching unit based on a measurement signal of the cycle measuring unit. And a programmable controller. 4. The programmable controller according to claim 1, wherein the second arithmetic processing unit is configured to manually select the switching unit.