JP3731423B2 - Method for creating reference pattern for failure diagnosis and failure diagnosis apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for creating a reference pattern for failure diagnosis and a failure diagnosis device applied to a system controlled by a sequencer.
[0002]
[Prior art]
Conventionally, in a system that controls various devices (equipment) using a sequencer (in the present invention, it means a programmable logic controller), on-off patterns of contacts (input contacts, output contacts, internal contacts) that are mutually related in the sequencer Is created in advance as a reference pattern, and when the equipment is automatically operated using a sequencer, the system determines the on / off pattern of each contact of the sequencer against the reference pattern to determine whether or not they match. A technique for diagnosing the presence or absence of abnormalities (that is, failure diagnosis) has been proposed (Japanese Patent Laid-Open No. 10-97318).
[0003]
The reference pattern is obtained by extracting changes in the ON / OFF of each contact when the sequencer is actually operated as time series information, and extracting what is considered to be related (regularity) in the time series information. Created. In other words, a required contact is selected from all the contacts, contacts that are judged to be regular to the selected contacts are extracted from all the contacts, and the ON / OFF changes of the extracted contact group are detected. It is used as a reference pattern. Here, in the technique described in the above publication, the presence / absence of regularity is determined based on only the on / off timing and the number of on / off times within one cycle.
[0004]
[Problems to be solved by the invention]
As described above, in the technique described in the above publication, the contact point of interest when creating the reference pattern is selected as the reference contact point, and the relationship between the on / off change of the selected reference contact point and the on / off change of other contact points is determined. Based on this, the presence or absence of regularity between the contacts is determined. As a result, when regularity is found by chance even though it is not related to changes in contact on / off, or even if related, it is easily affected by other factors and is likely to change even when it is unstable and operating normally. There is a case where the relationship is as follows. If such a contact point is included in the reference pattern, the degree of coincidence with the reference pattern may be reduced even if it is not abnormal or faulty, and an erroneous diagnosis may occur.
[0005]
The present invention has been made in view of the above reasons, and its purpose is to create a reference pattern with higher reliability than before by setting a reference pattern based on the ON / OFF relationship of related contacts. It is an object of the present invention to provide a method for creating a reference pattern for failure diagnosis, and to provide a failure diagnosis apparatus that further reduces the possibility of erroneous diagnosis by using this reference pattern.
[0006]
[Means for Solving the Problems]
The invention of claim 1 is a reference that is used when diagnosing the presence or absence of an abnormality in a system composed of a sequencer and equipment controlled by the sequencer, and is collated with an on / off pattern of a contact group of interest among sequencer contacts. A method for creating a pattern comprising a sequence program Output instruction at When the required contacts included in the Starting from the output command that includes the specified contact, starting from the sequence program until the next output command appears By tracking, other contacts that affect on / off of the designated contact are automatically extracted, and the designated contact and the extracted contact are defined as the contact group, and a desired plurality of contacts in the contact group are selected. A change in ON / OFF within a predetermined cycle of the contact is adopted as a reference pattern.
[0007]
In the present invention, the term “contact” is not a physical contact, but means an address that the sequencer treats as equivalent to a contact in a relay sequence. That is, an address whose bit value changes according to input or output corresponds to a relay contact of the input unit or a relay contact of the output unit. Further, the bit value stored by the output command is not directly used for external input / output, and an address used only for performing a logical operation with the value of another address is also handled as a contact. This address corresponds to the coil of the relay at the time of writing, and corresponds to the contact of the relay at the time of reading, and is hereinafter referred to as an internal contact. In addition, when mainly describing writing (that is, output) with respect to this address, it may be referred to as a relay coil.
[0010]
Claim 2 The invention of Claim 1 In the present invention, when another contact that affects the designated contact is turned on / off by another output command, the sequence from the other output command as a starting point until the next output command appears. By tracing, another process of automatically extracting other contacts that affect the specified contact from the sequence program is performed recursively.
[0011]
Claim 3 The invention of Claim 1 or claim 2 In the present invention, the contact point that first changes on / off at the start of execution of the sequence program among the contact points is selected as a reference contact, and the period until the next same change occurs in the reference contact is defined as one cycle. The change of ON / OFF within 1 cycle is employ | adopted as a reference | standard pattern about several desired contacts among these.
[0012]
Claim 4 The invention of Claim 3 In the invention, the reference pattern includes a set of a time interval and a change direction until the on / off of each other contact of the contact group first changes after the change of the reference contact within the one cycle. And
[0013]
Claim 5 The invention of Claim 4 In the invention, the reference pattern includes a time interval and a change direction of ON / OFF change of each contact after the ON / OFF of each other contact of the contact group first changes after the change of the reference contact within the one cycle. Is included.
[0014]
Claim 6 The invention of Claim 3 In the invention, the reference pattern includes a set of the number of times each contact constituting the contact group is turned on and off in the one cycle.
[0015]
Claim 7 The invention of Claim 3 In the invention, the reference pattern includes a set of ON / OFF time interval and change direction of each contact of the contact group after the change of the reference contact in the one cycle, and ON / OFF of each contact constituting the contact group. And a set of the number of times of off.
[0016]
Claim 8 The present invention is a failure diagnosis apparatus for diagnosing the presence or absence of an abnormality in a system comprising a sequencer and equipment controlled by the sequencer. Claim 7 A reference pattern creation unit that creates a reference pattern by applying the method for creating a reference pattern described in any one of the above, and ON / OFF of the contact group is compared with the reference pattern while a sequence program is being executed in a sequencer Failure diagnosis means for determining whether there is an abnormality in the system from the degree of coincidence, the reference pattern creation section reads out the sequence program from the sequencer and selects the contact group, and the sequence program in the sequencer From the time-series information recorded in the detection / recording means, the detection / recording means for recording the ON / OFF change of each contact as the time series information, and the ON / OFF change of the contact group selected by the contact selection means A diagnostic reference creation means for creating a reference pattern by extracting .
[0017]
DETAILED DESCRIPTION OF THE INVENTION
In the present embodiment, as illustrated in FIG. 1, a failure diagnosis apparatus 1 attached to a sequencer 2 that controls equipment 3 is illustrated. The failure diagnosis apparatus 1 is connected to the sequencer 2 via an appropriate interface or can perform data communication. The sequence diagnostics 2 (hereinafter simply referred to as a program) can be used to input, output, Capture changes in internal contact on / off. The failure diagnosis apparatus 1 can also read a program stored in the sequencer 2.
[0018]
The failure diagnosis apparatus 1 includes failure diagnosis means 11 for monitoring the operation of the sequencer 2 and diagnosing a failure of the system. The failure diagnosis means 11 pays attention during execution of the program as described in the prior art. By comparing the on / off changes of the input contact, output contact, and internal contact with a preset reference pattern, and determining the degree of coincidence with the reference pattern, it is determined whether there is an abnormality or failure in the equipment 3 or the sequencer 2. Therefore, the failure diagnosing unit 11 receives information about changes in ON / OFF of the input contact, the output contact, and the internal contact from the sequencer 3, and the reference pattern is input from the reference pattern creation unit 10 provided in the failure diagnosis apparatus 1.
[0019]
The reference pattern creation unit 10 includes a diagnostic reference creation unit 12, a detection / recording unit 13, and a contact selection unit 14. The diagnostic reference creation means 12 automatically extracts the reference pattern by extracting the on / off changes of the input contact, the output contact, and the internal contact of interest from the on / off information of each contact obtained by the sequencer 2 executing the program. It has a function to create. That is, the diagnostic reference creation means 12 extracts the on / off pattern of the input contact, output contact, and internal contact designated by the contact selection means 14 from the information stored in the detection / recording means 13 and creates a reference pattern. The detection / recording means 13 stores ON / OFF changes of all input contacts, output contacts, and internal contacts when the sequencer 2 is executing a program.
[0020]
By the way, in this embodiment, based on the program set in the sequencer 2, the input contact, the output contact, and the internal contact to which the contact selecting means 14 pays attention are selected in the following procedure, and the selected input contact and output contact are selected. The feature is that a reference pattern is created for internal contacts. Hereinafter, a procedure for selecting an input contact, an output contact, and an internal contact of interest from a program will be described.
[0021]
In general, a program can be expressed using mnemonics as shown in FIG. In the illustrated example, the left column indicates the step number, the second line indicates the operation part of the instruction, and the third and fourth lines indicate the address part of the instruction. The third line of the address part indicates the type of the input contact (X), the output contact (Y), and the internal contact (R), and the fourth line indicates a number for identifying each contact. In the example shown in the figure, five types of operation part mnemonic codes “ST”, “AND /”, “OUT”, “AND”, “OR” are used. It means an instruction to start operation at a contact, an instruction to connect normally closed settings in series, an instruction to output an operation result, an instruction to connect normally open contacts in series, and an instruction to connect normally open contacts in parallel.
[0022]
In addition, combinations of contacts and numbers (for example, “X12” and “Y10”) in the address part are associated with addresses in the memory, and the addresses of each input contact and each output contact are input units (input units). And each contact of the output unit (output unit). In other words, the input contact “X12” being on means that the information from the switch or sensor provided in the equipment 3 is on, and the output contact “Y10” being on is provided in the equipment 3. This means turning on the actuator and motor. Further, the internal contact is not a physical contact for inputting / outputting to / from the facility 3 but a contact virtually set to represent a logic equivalent to a relay sequence by a program. That is, the internal contact actually means a specific address in the memory. For example, “OUT R10” means that the result is written to the address corresponding to “R10” in the memory, and “OR R10” is the logical sum with the data stored in the address corresponding to “R10” in the memory. means. Therefore, “OUT R10” corresponds to a relay coil in the relay sequence, and “OR R10” corresponds to connecting normally open contacts in parallel.
[0023]
If the program written as shown in FIG. 4 is written as a ladder diagram, it becomes as shown in FIG. In the figure, the two vertical bars mean contacts, the contact with diagonal lines means a normally closed contact, and the contact without diagonal lines means a normally open contact. Further, the parenthesized symbol means output, and when this symbol corresponds to the internal contact, it corresponds to a relay coil. That is, the portion sandwiched between “ST” and “OUT” in the mnemonic program corresponds to one stage in the ladder diagram.
[0024]
By the way, if the program for one stage in the ladder diagram does not include specific application instructions (instructions for various operations, comparisons, data format conversions, etc.) and is described with only basic instructions in 1-bit units, that one stage It is considered that each of the constituent contacts is turned on and off at a substantially constant timing. Similarly, the contacts included in each stage associated by the internal contacts are considered to be turned on and off at substantially constant timing. In other words, each contact point of the basic command and the operation timing of the relay coil included in a program corresponding to one stage each when expressed in a ladder diagram or a program corresponding to a plurality of stages associated with internal contacts are associated with regularity. It can be said that.
[0025]
The contact selection means 14 extracts a contact group of interest from the program based on the above-described knowledge. That is, as shown in FIG. 2, the contact selecting means 14 first reads a program from the sequencer 2 (S1). Next, a person designates an appropriate contact (that is, an appropriate address corresponding to “OUT” in the program) that is the output of the program for one stage in the ladder diagram (S2). That is, the contact that is the address part of the output command is indicated. At this stage, human work is involved, but if the program is expressed in mnemonic, an arbitrary address corresponding to “OUT” may be specified, and if expressed in a ladder diagram, it corresponds to one-stage output. You only need to specify the address, so it doesn't take much time. When the contact is designated in this way, the contact related to the designated contact is extracted from the program by the following procedure (S3).
[0026]
As shown in FIG. 3, the extraction of the contact is started by searching for and extracting an output command in which the designated contact is included in the address part (S1). When an output command including a contact point instructed in the program is extracted, extraction of another related contact point is started from this position (S2). That is, the program is first traced back from the starting point by decrementing the program steps (S3). In each step, it is first determined whether or not the operator is an output command (S4). If it is not an output command, it is determined whether or not the contact is already extracted (S5). If the contact is not already extracted, it is regarded as a contact related to the designated contact and is registered (S6). Further, it is determined whether or not the registered contact is an input contact (S7). If it is an input contact, the process returns to step S3 and the program is further traced back. In this way, the contact extraction ends when the next output command is found. In the above-described processing, since the program is extracted step by step in the program, not only the contacts connected in series on the ladder diagram (contacts where the operator is “AND”), but also the contacts connected in parallel ( All contacts for which the operator is “OR” are also extracted.
[0027]
In the above-described processing, one stage of contacts in the ladder diagram can be extracted. On the other hand, if it is determined in step S7 that the input contact is not an input contact, a process of extracting a related contact using the contact as a designated contact is performed (S8). That is, the procedure shown in FIG. 3 is recursive. For example, in the program shown in FIGS. 4 and 5, if the first designated contact is the output contact Y10, “ANDR11” is extracted, and “R11” is an internal contact and not an input contact. , An output command having “R11” in the address part is extracted, and the program is traced back starting from this output command. Thus, the contact point related to “R11” is extracted, and when the output command is found in step S4, the extraction of the contact point related to “R11” is completed. Next, returning to the original routine, “ST R10”, which is the previous step of the instruction “AND R11” including “R11”, is extracted, and the output instruction including “R10” is programmed as described above as a starting point. The process going back is performed. After the extraction of the contact point related to “R10” is completed, the process returns to the original routine, so that “OUT R11” is extracted. Since this is an output command, the process ends in step S4.
[0028]
In the above example, it is possible to extract related contacts from a multi-stage program in the ladder diagram by recursive processing. However, steps S7 and S8 are omitted, and the process returns from step S6 to step S3. For example, relevant contact points are extracted from only one stage program in the ladder diagram. When a relatively small number of contact ON / OFF timings are used as the reference pattern, such processing may be performed, and the burden required for extracting the contact point of interest and the matching with the reference pattern can be reduced.
[0029]
As described above, the diagnostic reference creation means 12 creates a reference pattern by paying attention to the contacts extracted by the signal selection means 14 by the processing shown in FIGS. That is, when each contact (input contact, output contact, internal contact) is turned on / off while the program is executed in the sequencer 2, the detection / storage means 13 stores the on / off change point as time series information, and the diagnostic criteria The creating unit 12 extracts the on / off pattern related to the contact group extracted as described above from the time series information stored in the detection / storage unit 13.
[0030]
For example, if the output contact Y10 is specified in the programs shown in FIGS. 4 and 5 and all the contacts are extracted by the recursive process shown in FIG. 3, the input contacts X2, X10, X12, X13, the internal contact R10 are extracted. , R11 on / off patterns are extracted. Therefore, the input contacts X2, X10, X12, X13, the output contact Y10, and the internal contacts R10, R11 are taken as a contact group, and the ON / OFF pattern of these contact groups when the program is actually executed by the sequencer 2 is extracted. To do. Now, assuming that the ON / OFF pattern of these contact groups is as shown in FIG. 6, the diagnostic reference creating means 12 takes note of the contact group of interest during one cycle of the program (the sequence program is executed cyclically). First, a contact whose ON / OFF changes is extracted as a reference contact. In the illustrated example, the input contact X2 is a reference contact.
[0031]
Here, during the continuous operation of the equipment 3, it is difficult for the failure diagnosis apparatus 1 to know the start point of one cycle of the program from the ON / OFF pattern of the contact group. The reference contact point is determined by setting the time point at which the start time of the program can be grasped, such as the time point when the operation of the equipment 3 is started), the time point when the operation of the equipment 3 is switched, and immediately after initialization. In other words, the contact whose ON / OFF changes first at the start of program execution is selected as the reference contact.
[0032]
When the reference contact is determined as described above, the period until the next same change in the reference contact ON / OFF is defined as one cycle, and the contact group extracted as the target contact group within the one cycle period is turned on / off. Is recorded using the change point of the reference contact as a reference, and the time series information obtained in this way for the contact group of interest is used as the reference pattern. That is, a set of a time interval and a change direction until the on / off of each other contact of the contact group first changes is used as the reference pattern with the change point of the reference contact as a base point. Since this reference pattern includes only one on / off change for each contact, when setting a more accurate reference pattern, the time for the second and subsequent on / off changes of each contact included in the contact group. A set of interval and change direction is also included in the reference pattern. In short, a set of the time interval and the change direction of the ON / OFF change points of all the contacts in the contact group is used as the reference pattern with the change point of the reference contact as a base point within one cycle. An example of the reference pattern thus set is shown in FIG. In the figure, each row represents a different contact, and the numerical value represents time (for example, the number of clocks). An upward arrow indicates that the change direction is from off to on, and a downward arrow indicates that the change direction is from on to off.
[0033]
As the reference pattern, a set of the number of times each contact of the contact group is turned on and off in one cycle of the program may be used. According to the example shown in FIG. 6, the number of times each contact is turned on and off can be expressed as shown in FIG. That is, in the case of the input contact X2, since it is one cycle from the first turning on to the next turning on, the number of times of turning on is counted as zero during one cycle, and the turning off during one cycle. Since the number of times is 1, it is expressed as 0/1 in the sense that ON is 0 and OFF is 1. In this way, the number of on and off times may be used as the reference pattern. In addition, both the set of the ON / OFF time interval and change direction of each contact constituting the contact group and the set of the number of ON and OFF times may be used together in the reference pattern.
[0034]
When the reference pattern is determined as described above, the failure diagnosis unit 11 reads the on / off state of the contact group during the operation of the sequencer 2, and the on / off state of the read contact group and the reference pattern created by the diagnostic reference creation unit 12 is read. The matching degree (similarity) between the two is obtained by collating the pattern. When the matching degree is low, it is determined that some abnormality or failure has occurred in the sequencer 2 or the equipment 3. Since the contact group that reads the ON / OFF change from the sequencer 2 may be only the contact group included in the reference pattern, the failure diagnosis unit 11 selects the contact group to be read based on the reference pattern. Further, if the change of each contact group is read from the sequencer 2 on the basis of the time when the reference contact in the reference pattern changes in the same manner as the reference pattern, the degree of coincidence can be easily obtained. Here, for the degree of coincidence, the time difference between the reference pattern and the operation time may be used for the ON / OFF pattern of each contact group. A threshold is set for the time difference for each contact, and there is a time difference exceeding the threshold for any contact. When it occurs, it is judged as an abnormality or failure.
[0035]
By the way, in the above example, the period until the same change as the first change occurs in the reference contact is regarded as one cycle of the program, and the on / off pattern for one cycle of the contact group of interest is used as the reference pattern. There may be variations in the on / off timing of the contacts. Therefore, the contact group obtained by the signal discriminating means 14 is treated as a candidate for creating a reference pattern, the contact group on / off timing is obtained for a plurality of cycles, and the on / off timing variation is obtained for each contact. Deviations may be used for evaluation of the degree of variation, and when the deviation is equal to or less than a prescribed threshold value, the variation is employed as little variation. In this way, if a contact group with less variation in on / off timing is extracted from the contact group extracted based on the program and used for the reference pattern, the reliability of the reference pattern is enhanced. Even when the number of times the contact group is turned on and off is used as the reference pattern, the variation may be determined, and only the contact having a small variation may be employed.
[0036]
【The invention's effect】
The invention of claim 1 is a reference that is used when diagnosing the presence or absence of an abnormality in a system composed of a sequencer and equipment controlled by the sequencer, and is collated with an on / off pattern of a contact group of interest among sequencer contacts. A method for creating a pattern comprising a sequence program Output instruction at When the required contacts included in the Starting from the output command that includes the specified contact, starting from the sequence program until the next output command appears By tracking, other contacts that affect on / off of the designated contact are automatically extracted, and the designated contact and the extracted contact are defined as the contact group, and a desired plurality of contacts in the contact group are selected. It is characterized by adopting a change of ON / OFF within a predetermined one cycle period as a reference pattern for the contact, and in the prior art, it is considered that the selected contact is a reference contact and has regularity from the ON / OFF of the contact. In contrast, the invention of claim 1 Specify the contact included in the output command, trace the sequence program from this contact until the next output command appears, Contacts that affect the specified contacts from the program Automatically Since the specified contacts and the extracted contacts are used as contact groups, and the ON / OFF changes of each contact in the contact group are used as a reference pattern, contacts that are not related or that are likely to change even if related There is no possibility of adopting Determine contact groups that affect specified contacts reliably and quickly. A highly reliable reference pattern can be created.
[0038]
In particular, 2 Since the contacts are tracked while being limited between two output commands, the contact groups can be determined in a relatively short time without requiring an unnecessarily long time to determine the contact groups. In addition, since all the contacts between the two output commands are tracked, not only contacts in a series connection relationship but also contacts in a parallel connection relationship are tracked, and related contacts are reliably extracted. be able to.
[0039]
Claim 2 The invention of Claim 1 In the present invention, when another contact that affects the designated contact is turned on / off by another output command, the sequence from the other output command as a starting point until the next output command appears. By tracking, it is characterized by performing recursively the process of automatically extracting other contacts that affect the specified contact from the sequence program, and not only the contact between two output commands, Contacts that affect the contacts between the two output commands will also be tracked, and the related contacts can be extracted without omission.
[0040]
Claim 3 The invention of Claim 1 or claim 2 In the present invention, the contact point that first changes on / off at the start of execution of the sequence program among the contact points is selected as a reference contact, and the period until the next same change occurs in the reference contact is defined as one cycle. The change of ON / OFF within one cycle is adopted as a reference pattern for a plurality of desired contacts of the reference, and the reference contact that is the base point of the reference pattern is the first at the start of execution of the sequence program in the contact group. Since the reference pattern is defined in the period until the same change occurs in the ON / OFF of this reference contact, the base point of the reference pattern can be set clearly and the reference pattern can be set with high reproducibility. can do.
[0041]
Claim 4 The invention of Claim 3 In the invention, the reference pattern includes a set of a time interval and a change direction until the on / off of each other contact of the contact group first changes after the change of the reference contact within the one cycle. Since the time interval from the change of the reference contact to the change of each contact constituting the contact group is used as the reference pattern, the ON / OFF change of each contact and the reference pattern while the sequencer is actually executing the sequence program Can be numerically determined by the time difference and quantitative failure diagnosis can be performed by using this reference pattern.
[0042]
Claim 5 The invention of Claim 4 In the invention, the reference pattern includes a time interval and a change direction of ON / OFF change of each contact after the ON / OFF of each other contact of the contact group first changes after the change of the reference contact within the one cycle. Since the time interval of on / off conversion of each contact within one cycle is used as a reference pattern, the on / off change of each contact during the sequencer actually executing the sequence program is used. The degree of coincidence when collating with the reference pattern can be numerically determined by the time difference, and quantitative failure diagnosis can be performed by using this reference pattern. In addition, by using the on / off time interval of each contact, if this reference pattern is used, failure diagnosis is performed with a large amount of information, leading to accurate failure diagnosis.
[0043]
Claim 6 The invention of Claim 3 In the invention, the reference pattern includes a set of the number of times each contact constituting the contact group is turned on and off within the one cycle, and only the number of times the contact group is turned on / off is collated. In the failure diagnosis, the reference pattern and the operation of the sequencer can be easily verified, and the verification can be performed in a short time. Further, compared with the case where the time interval is used for the reference pattern, the capacity required for storing the reference pattern can be reduced.
[0044]
Claim 7 The invention of Claim 3 In the invention, the reference pattern includes a set of a time interval and a change direction of each contact of the contact group after the change of the reference contact in the one cycle, and ON of each contact constituting the contact group. It is characterized by including a set of the number of times of off, and both the time interval and the number of times of on and off are used for the reference pattern. It becomes possible.
[0045]
Claim 8 The present invention is a failure diagnosis apparatus for diagnosing the presence or absence of an abnormality in a system comprising a sequencer and equipment controlled by the sequencer. Claim 7 A reference pattern creation unit that creates a reference pattern by applying the method for creating a reference pattern described in any one of the above, and ON / OFF of the contact group is compared with the reference pattern while a sequence program is being executed in a sequencer Failure diagnosis means for determining whether there is an abnormality in the system from the degree of coincidence, the reference pattern creation section reads out the sequence program from the sequencer and selects the contact group, and the sequence program in the sequencer From the time-series information recorded in the detection / recording means, the detection / recording means for recording the ON / OFF change of each contact as the time series information, and the ON / OFF change of the contact group selected by the contact selection means A diagnostic reference creation means for creating a reference pattern by extracting The operation of the sequencer is recorded in the detection / recording means as time-series information, and the time-series information regarding the contacts included in the contact group obtained by tracking the sequence program is extracted to create the reference pattern. As in the case of the present invention, there is no possibility of adopting, as a reference pattern, an unrelated contact or a contact that is easily changed even if related, and a highly reliable reference pattern can be created. Also, the reference pattern created in this way is checked against the ON / OFF changes of each contact during sequencer operation to determine the presence or absence of system abnormality from the degree of coincidence. Therefore, the determination of the presence or absence of abnormality can also be performed with high reliability.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a failure diagnosis apparatus used in an embodiment of the present invention.
FIG. 2 is an operation explanatory view of the above.
FIG. 3 is an operation explanatory diagram of the above.
FIG. 4 is a diagram showing an example in which the sequence program is described in mnemonic.
FIG. 5 is a diagram showing an example in which the sequence program is described in a ladder diagram.
FIG. 6 is an operation explanatory diagram showing a time chart of the operation example same as above.
FIG. 7 is an operation explanatory view showing an on / off change example of each contact in the same as above.
FIG. 8 is an operation explanatory diagram showing an example of the number of times each contact is changed between on and off in the same as above.
[Explanation of symbols]
1 Failure diagnosis device
2 Sequencer
3 facilities
10 Reference pattern generator
11 Failure diagnosis means
12 Diagnostic criteria preparation means
13 Detection and recording means
14 Contact selection means

Claims (8)

This is a method for creating a reference pattern that is used when diagnosing the presence or absence of an abnormality in a system consisting of a sequencer and equipment controlled by the sequencer, and that matches the on / off pattern of the contact group of interest among the sequencer contacts. When the required contact included in the output command is specified in the sequence program , the output command including the contact specified in the sequence program is taken as the starting point until the next output command appears. By tracking, other contacts that affect on / off of the designated contact are automatically extracted, and the designated contact and the extracted contact are set as the contact group, and a desired plurality of contacts in the contact group are selected. It is characterized in that a change in ON / OFF within a predetermined cycle of a contact is adopted as a reference pattern. How to create a reference pattern for fault diagnosis. When another contact that affects the specified contact is turned on / off by another output command, by tracing the sequence program starting from the other output command until the next output command appears. 2. The method for creating a reference pattern for fault diagnosis according to claim 1, wherein the process of automatically extracting other contacts that affect the designated contact from the sequence program is performed recursively . Of the contact groups, the first contact point that changes on / off at the start of execution of the sequence program is selected as the reference contact point, and the period until the next same change occurs in the reference contact point is one cycle. 3. The method for creating a reference pattern for fault diagnosis according to claim 1, wherein a change in ON / OFF within one cycle is adopted as a reference pattern for the plurality of contacts . The reference pattern includes a set of a time interval and a change direction until an ON / OFF of each other contact of the contact group first changes after a change of the reference contact within the one cycle. 3. A method for creating a reference pattern for failure diagnosis according to 3 . The reference pattern includes a set of a time interval and a change direction of the ON / OFF change of each contact after the ON / OFF of each other contact of the contact group first changes after the change of the reference contact within the one cycle. The method for creating a reference pattern for fault diagnosis according to claim 4 . 4. The method of creating a reference pattern for fault diagnosis according to claim 3, wherein the reference pattern includes a set of the number of times each contact constituting the contact group is turned on and off in the one cycle . The reference pattern is a set of the on / off time interval and change direction of each contact of the contact group after the change of the reference contact in the one cycle, and the number of times of turning on and off each contact constituting the contact group. The method of creating a reference pattern for fault diagnosis according to claim 3, wherein: A failure diagnosis device for diagnosing the presence or absence of an abnormality in a system comprising a sequencer and equipment controlled by the sequencer, wherein the reference pattern creation method according to any one of claims 1 to 7 is applied. A reference pattern creating unit for creating a reference pattern, and a failure diagnosis means for checking on / off of the contact group with the reference pattern while executing a sequence program in a sequencer and determining whether there is an abnormality in the system based on the degree of coincidence The reference pattern creation unit reads out a sequence program from a sequencer and selects the contact group, and records on / off changes of each contact when the sequence program is executed in the sequencer as time-series information. ON / OFF of contact group selected by detection / recording means and contact selection means Fault diagnosis apparatus characterized by comprising a diagnostic reference creating means for creating a reference pattern by extracting from the time-series information recorded in a change in the detection and recording means.

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