JP5818758B2 - PLC system - Google Patents

Description

  The present invention relates to a programmable logic controller (PLC) unit and a PLC system.

  Conventionally, a programmable logic controller system (hereinafter referred to as a PLC system) is configured by appropriately combining various PLC units. The PLC unit includes, for example, a power supply unit of a power supply source, a CPU unit that controls the entire PLC system, and a motion CPU that controls a servo motor via a servo amplifier attached to a drive unit of a production apparatus or facility apparatus ( Central Processing Unit), switches installed at appropriate locations in production equipment and equipment, input units for inputting sensor signals, output units for outputting control output to actuators, etc., and communication units for connecting to communication networks Depending on the intended use, various functional units are prepared.

  For example, as described in Patent Document 1, primary diagnosis of whether or not an abnormality has occurred in a PLC system is performed based on lighting / extinguishing / flashing of an ERR LED (Light Emitting Diode) of a CPU unit.

JP 2005-157665 A

  However, in the above conventional technique, in order to identify a unit in which an error has occurred, it is necessary to connect a computer in which a dedicated application for analyzing the error code is installed to the PLC system.

  Also, when checking the error level indicating the severity of the failure of each unit (for example, the severity level of severe, moderate, or mild), an error code obtained by connecting a computer to the PLC system is used. Since it was necessary to analyze and determine the contents of the error code, individual technical knowledge was required.

  Furthermore, although the PLC system is operating with the desired effect, for example, when there is an error in any unit such as a communication error in the network unit, the LED arrangement, name, and behavior differ from unit to unit. In order to recognize the error, it is necessary to grasp all the arrangements and names of the different LEDs for each unit and check the display state of each unit LED, that is, whether it is lit, extinguished, or blinking. The burden was growing.

The present invention was made in view of the above, P LC system without connecting a computer installed with a dedicated application for analyzing the error code Ru can check and the error level whether an error occurred The purpose is to obtain.

  In order to solve the above-described problems and achieve the object, the present invention provides an error detection unit for detecting an error generated in a PLC unit and an error detection unit in a PLC system formed by connecting a plurality of PLC units. An error level determination unit that determines an error level of a detected error, and an error level display unit that displays a determination result of the error level determination unit. The error level determination unit includes a plurality of error levels common to other PLC units. And the error content generated in the PLC unit associated with the error level, and the error level corresponding to the error content detected by the error detection unit is displayed on the error level display unit.

  According to the present invention, the presence / absence of an error and the error level can be confirmed without connecting a computer in which a dedicated application for analyzing an error code is installed.

FIG. 1 is a diagram showing a configuration of an embodiment of a PLC system using a PLC unit according to the present invention. FIG. 2 is a diagram illustrating a configuration of the PLC unit. FIG. 3 is a diagram illustrating an example of an error definition. FIG. 4 is a flowchart showing the flow of error display operation of the PLC unit. FIG. 5 is a schematic external view of a PLC system in which a plurality of PLC units according to the present embodiment are connected.

  Embodiments of a PLC unit and a PLC system according to the present invention will be described below in detail with reference to the drawings. Note that the present invention is not limited to the embodiments.

Embodiment.
FIG. 1 is a diagram showing a configuration of an embodiment of a PLC system using a PLC unit according to the present invention. The PLC system 10 is configured by connecting a plurality of PLC units 1 (1 ₁ to 1 _n ). In the following description, when it is not necessary to distinguish each of the PLC units 1 ₁ to 1 _n , the suffix is omitted and the PLC unit 1 is described.

  FIG. 2 is a diagram illustrating a configuration of the PLC unit. The PLC unit 1 includes a unit specific function unit 11 and an error diagnosis function unit 12. The unit specific function unit 11 is a function unit that implements a specific function corresponding to the model of the PLC unit. For example, in the case of a CPU unit, the unit specific function unit 11 includes an arithmetic device. In the case of a network unit, the unit specific function unit 11 includes a communication I / F (interface). The unit-specific function unit 11 includes a watchdog timer (hereinafter abbreviated as WDT) 111 and a microcomputer (not shown) that controls the watchdog timer in common with each unit.

  Note that, like an I / O (Input / Output) unit, an input / output terminal is provided as the unit-specific function unit 11, but the above-described WDT 111 may not be provided. As will be described later, the WDT 111 has a function of turning off the first LED 124 when no error is detected in the error diagnosis function unit 12. In the present embodiment, when the PLC unit 10 does not have the WDT 111, the error diagnosis function unit 12 determines the error level using only the detection of the error as a trigger, and the first and second LEDs 124 and 125 The display state of lighting, blinking, and extinguishing is controlled.

  The error diagnosis function unit 12 includes an error detection unit 121, an error level determination unit 122, a display control unit 123, a first LED 124, and a second LED 125.

  The error level determination unit 122 has an error definition 122a. The error level determination unit 122 determines whether the error detected by the error detection unit 121 corresponds to mild, moderate, or severe based on the error definition 122a. The error detection unit 121 detects various errors that occur in the PLC unit 1, and the error detection method differs for each monitoring target. For example, when detecting an error due to a decrease in battery voltage, the error detection unit 121 monitors the battery voltage, and confirms that the error has occurred by confirming that the voltage is lower than the voltage necessary to maintain the function as the battery voltage. To detect. As another example, the error detection unit 121 detects an error by confirming that an appropriate calculation result cannot be output by division using 0 as a parameter. That is, the error detection unit 121 detects an error by confirming whether or not the function of each function unit can be maintained or exhibited.

  FIG. 3 is a diagram illustrating an example of the error definition 122a. The error definition 122a is obtained by classifying the error detected by the error detection unit 121 into “severe”, “medium”, and “mild” for each degree of influence on the stable operation of the PLC unit. The error definition 122a defines which level each error that can be detected by the error detection unit 121 corresponds to. Note that the user may be able to set an error level for at least some of the errors defined in the error definition 122a. For example, an arbitrary error whose level is classified as medium in the default setting can be changed lightly by the user setting.

When the user can change the error definition 122a, the error definition 122a may be shared by each of the PLC units 1 ₁ to 1 _n constituting the PLC system 10. For example, the error definition 122a may be changed on an engineering tool for performing various settings of the PLC system 10, and the changed error definition 122a may be written to each of the PLC units 1 ₁ to 1 _n in _{one operation} . Further, for example, an error definition 122a written in a specific type of PLC unit 1 such as a CPU unit may be read by another connected PLC unit 1.

  When the error detection unit 121 detects an error that is not defined in the error definition 122a, for example, the error level determination unit 122 temporarily determines the error level as “severe”. Then, after confirming the cause of the error by the user, the error is added to the error definition 122a according to the severity of the failure of the unit.

  When the error level determination unit 122 determines the error level as described above, the error level can be determined uniformly without depending on errors inherent in the PLC unit such as the CPU unit, the network unit, and the I / O unit. It is possible to display errors uniformly in the PLC unit.

  Subsequently, the display control unit 123 changes the combination of the display states of the first and second LEDs 124 and 125 according to the presence or absence of error detection by the error detection unit 121 and the determination result of the error level determination unit 122. Thus, the first and second LEDs 124 and 125 are caused to function as an error level display unit. Specifically, the display control unit 123 performs control to turn on the first LED 124 and turn off the second LED 125 when the error detection unit 121 does not detect an error. When the error detection unit 121 detects an error, the display control unit 123 changes the display state of the second LED 125 according to the determination result of the error level determination unit 122. When the determination result of the error level determination unit 122 is mild, the display control unit 123 performs control so that the first LED 124 is turned on and the second LED 125 is turned on. Further, when the determination result of the error level determination unit 122 is medium, the first LED 124 is turned on and the second LED 125 is blinked. Further, when the determination result of the error level determination unit 122 is severe, the display control unit 123 performs control so that the first LED 124 and the second LED 125 are turned off.

  The first LED 124 is mounted so that it turns off when the WDT 111 times out. A microcomputer (not shown) included in the unit specific function unit 11 sends a reset signal to the WDT 111 at a predetermined timing to control the WDT 111 so that it does not time out. When a severe error occurs in the PLC unit 1 and the reset signal is not sent to the WDT 111, the WDT 111 times out.

  The error detection unit 121, the error level determination unit 122, and the display control unit 123 may have a configuration using dedicated hardware (for example, ASIC (Application Specific Integrated Circuit)), or the unit specific function unit 11 may When an arithmetic device is provided, the function may be realized by software processing by the arithmetic device.

  FIG. 4 is a flowchart showing a flow of error display operation of the PLC unit 1. During the operation of the PLC system 10, the error detection unit 121 monitors the occurrence of an error in the PLC unit 1 (step S101). At this time, the display control unit 123 turns on the first LED 124 and turns off the second LED 125. When the error detection unit 121 detects an error (step S101 / Yes), the error level determination unit 122 determines which level the error has occurred in the PLC unit 1 based on the error definition 122a, and the display control unit 123 is notified (step S102). When the error detection unit 121 does not detect an error (step S101 / No), the process returns to step S101.

  When notified from the error level determination unit 122 that the error that has occurred is minor (step S102 / mild), the display control unit 123 turns on the second LED 125 (step S103). When the error level determination unit 122 notifies that the error that has occurred is moderate (step S102 / medium), the display control unit 123 causes the second LED 125 to blink (step S104). Further, when notified from the error level determination unit 122 that the error that has occurred is severe (step S102 / severe), the display control unit 123 turns off the first LED 124 and the second LED 125 (step S102). S105).

  When an error that prevents the PLC unit 1 from operating normally occurs, the microcomputer (not shown) included in the unit specific function unit 11 does not output a reset signal to the WDT 111, so that the WDT 111 times out. In this case, the error detection unit 121 detects that the WDT 111 has timed out as a kind of error, and notifies the error level determination unit 122 that the WDT 111 has timed out (step S101 / Yes). When the error level determination unit 122 is notified from the error detection unit 121 that the WDT 111 has timed out, the error level determination unit 122 performs display control to indicate that a severe error has occurred regardless of the content of the error defined in the error definition 122a. Notification to the unit 123 (step S102 / severe). Thereby, even if the error detection unit 121 does not detect the error defined in the error definition 122a, the function of turning off the first LED 124 when the WDT 111 times out is realized. In this case, since the display control unit 123 cannot control the display state of the second LED 125, it is uncertain whether the display state of the second LED 125 is turned on, turned off, or blinked in the process of step S105. . However, since the first LED 124 is lit when no error is detected or when a minor or moderate error is detected, the occurrence of a severe error can be determined only by the display state of the first LED 124. .

FIG. 5 is a schematic external view of a PLC system in which a plurality of PLC units according to the present embodiment are connected. Since each of the PLC units 1 ₁ to 1 _n having the error diagnosis function unit 12 is connected to form the PLC system 10, even when errors occur simultaneously in a plurality of PLC units 1 in the PLC system 10, It is possible to easily determine which of the PLC units 1 ₁ to 1 _{n has} an error. In addition, each of the PLC units 1 ₁ to 1 _n is arranged in a layout in which the first LED 124 and the second LED 125 are shared regardless of the type of the unit specific function unit 11. Accordingly, when the user confirms whether or not an error has occurred and the error level, the first LED 124 and the second LED 125 are searched for in the PLC unit 1, and which of the two LEDs is the first LED 124. It is not necessary to confirm which is the second LED 125, and it is easy to confirm whether an error has occurred or the error level. In addition, as shown in FIG. 5, by displaying names in the vicinity of each of the first LED 124 and the second LED 125, it is possible to prevent the first LED 124 and the second LED 125 from being mistaken. For example, in the case of a CPU unit or a power supply unit, “READY” is displayed as a name indicating the primary diagnostic LED in the vicinity of the first LED 124, and in the case of a unit other than the CPU unit or the power supply unit, The name “RUN” is displayed near the first LED 124 as a name indicating that the LED is a primary diagnosis LED. For all units, “ERROR” (or “ERR” as an abbreviation) is displayed near the second LED 125 as an error confirmation LED. In this way, the first LED 124 and the second LED 125 can be easily distinguished.

  Here, in the PLC unit, the LEDs are arranged on the front surface of the PLC unit with a common layout. However, in the present embodiment, the arrangement of the LEDs with respect to the front surface of the PLC unit is not limited to common use. If the unit's height direction size is different, the LED may be installed at the same front surface position with respect to the height direction from the PLC unit installation surface, and the PLC unit's width direction size. If they are different, the LEDs may be installed at the same position with respect to the direction from one side surface of the front surface of the PLC unit. In this manner, by providing regularity to the user's line of sight at the LED unit LED installation position, it is easy to check for error occurrence and error level.

  In FIG. 5, the LED is provided above the front surface of the PLC unit, but the LED may be provided in the direction of the installation surface of the PLC unit. Thereby, even when the position of the PLC unit in the height direction is different, regularity can be easily provided in the LED installation position with respect to the height direction from the PLC unit installation surface.

  According to the present embodiment, the user can confirm whether or not an error has occurred and the error level without connecting a computer on which a dedicated application is installed to the PLC system. In addition, since technical knowledge such as error code analysis is not required, it is possible to quickly grasp the level of an error that has occurred.

  In the above embodiment, the case where the error level is classified into three levels of mild, moderate, and severe is taken as an example, but the error level can be classified into four or more levels, It is also possible to classify into a few stages. Moreover, the assignment of the display state to light / medium / severe is an example, and assignment different from the above example may be performed.

  In the present embodiment, the method of displaying the contents of the error level by the combination of two LEDs has been described. However, an LED is provided in the CPU unit for each error level, and the LED corresponding to the error level is turned on or By flashing, the user may be notified of the error level. Alternatively, the blinking speed of the LED may be set for each error level, and the error level may be notified by the blinking speed.

  Moreover, although LED is used in this Embodiment, what is necessary is just a means which can notify an error to a user, and notification by panels, such as a liquid crystal panel, may be sufficient.

  As described above, the PLC unit according to the present invention is useful in that it can display the level of an error that has occurred without connecting a computer in which a dedicated application for analyzing an error code is installed. Suitable for application to large-scale PLC systems.

  1 PLC unit, 10 PLC system, 11 unit specific function unit, 12 error diagnosis function unit, 111 watchdog timer, 121 error detection unit, 122 error level determination unit, 122a error definition, 123 display control unit, 124 first LED 125 Second LED.

Claims (5)

An error detector for detecting errors in the P LC unit,
An error level determination unit for determining an error level of the error detected by the error detection unit;
An error level display unit for displaying a determination result of the error level determination unit,
The error level determination unit holds a plurality of error levels that are common to other PLC units, and details of errors that occur in the PLC unit linked to the error level, and details of errors detected by the error detection unit A PLC system in which a plurality of PLC units are connected , wherein an error level corresponding to the error level is displayed on the error level display unit ,
Each PLC level error determination unit of the PLC unit determines the error level independently of other PLC units, and displays the error level on the error level display unit . 2. The PLC system according to claim 1, wherein an arrangement position of the error level display section in the PLC unit is common to an arrangement position of the error level display section of the other PLC unit. 3. The PLC system according to claim 1, wherein the error level display unit includes a plurality of display means, and displays the error level by a combination of display methods of the display means. 4. The PLC system according to claim 1, wherein the error level display unit is an LED. The error level determination unit determines the error level of the error detected by the error detection unit in one of three levels of mild, moderate, and severe,
4. The PLC system according to claim 3, wherein the error level display unit displays the error level by a combination of lighting and / or blinking of LEDs serving as display means.

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