JPWO2013124974A1 - Fault detection method and slave station terminal used for that method - Google Patents

Abstract

In a control / monitor signal transmission system in which data transmission is performed by a transmission synchronization method, even when only one of an output unit or an input unit is connected to one slave station, output is performed on the master station side Provided is a failure detection method capable of discriminating between a failure of a terminal and an input unit, and a slave station terminal used for the method. A plurality of slave stations connected by a common data signal line with a master station take control data for the reference station or monitoring data transmitted from the reference station as reference data from a transmission signal with a predetermined other station as a reference station. . Then, the time from the change in the change direction specified by the reference data to the change in the change direction specified by the output data for the output unit to which the own station corresponds or the input data from the input unit to which the own station corresponds is obtained as the interval time. Then, the interval time is compared with a predetermined threshold value. [Selection] Figure 1

Description

  The present invention reduces the number of signal lines between a master station connected to a control unit and a plurality of output units and input units, or a plurality of slave stations corresponding to a plurality of controlled devices, and connects them with a common data signal line. In a control / monitoring signal transmission system that transmits data using a transmission synchronization method such as synchronizing with a transmission clock, the present invention relates to a failure detection method for detecting a failure in an output unit and an input unit and a slave station terminal used in the method. It is. The output unit operates in accordance with an instruction from the control unit, and an actuator, a (stepping) motor, a solenoid, a solenoid valve, a relay, a thyristor, and the like correspond to this. On the other hand, the input unit transmits information related to the output unit to the control unit, and a reed switch, a micro switch, a push button switch, a photoelectric switch, various sensors, and the like correspond to this. In addition, the controlled device is a device composed of an output unit and an input unit.

  In a control system including a control unit, a plurality of output units and input units, or a plurality of controlled devices, so-called wiring saving, which reduces the number of wirings, is widely implemented. As a general technique for reducing the wiring, a parallel signal and a serial signal are used instead of a parallel connection that directly connects a plurality of output units and input units or signal lines extending from a controlled device to the control unit. The master station and the plurality of slave stations having the conversion function are connected to the control unit, the plurality of output units and the input unit, or the plurality of controlled devices, respectively, and common data between the master station and the plurality of slave stations. A method of exchanging data with a serial signal via a signal line is widely adopted.

  When wiring saving is realized, when a failure of the output unit, input unit, or controlled device cannot be specified on the control unit side in a state where a large number of slave stations are connected, move away from the control unit. It is necessary to check each output unit, input unit, or controlled device, and it takes a lot of man-hours to identify the failed part.

  Therefore, the present applicant has proposed a remote wiring check system disclosed in Japanese Patent Application Laid-Open No. 2011-114449 as a system for identifying a disconnection failure between a slave station and an input unit and an output unit on the control unit side. ing. In this remote wiring check system, in a control / monitor signal transmission system including a single control unit and a plurality of controlled devices, a connection between a master station and a slave station connected by a common data signal line with reduced wiring is possible. A management data area including connection data indicating a wiring state is provided, which is different from a control / monitor data area composed of control data (output data) and monitoring data (input data) transmitted simultaneously in both directions. In the connection data, short-circuit information, disconnection information, and normal information are identified. For this reason, it is possible to easily check the wiring connection state between the slave station itself, the slave station and the input unit, or between the slave station and the output unit without reducing the input data (monitoring data) capacity of the signal.

  Also, in Japanese Patent Laid-Open No. 2006-331449, the ON or OFF state of the OUT terminal to which the output device (output unit) is connected is changed by OUT data serially communicated with the master unit (master station). A function for acquiring start time information, a function for acquiring stop time information when the ON or OFF state of the IN terminal to which the input device (input unit) is connected, and start time information and stop time information A slave (slave station) having a calculation function for calculating an operation time of an output device based on the above is disclosed. According to this slave (slave station), the operation time of the output device or input device is obtained and compared with the setting information for specifying the normal range of the output device or input device. It is possible to determine whether it is normal or whether the replacement time is approaching.

JP 2011-114449 A JP 2006-331449 A

  However, in the above-described conventional method for obtaining the operation time of the output unit and the input unit in the slave station, both the start time information of the OUT terminal to which the output unit is connected and the stop time information of the IN terminal to which the input unit is connected are obtained. There were cases where it was difficult to do. That is, when both the output unit and the input unit are connected to one slave station, the start time information and the stop time information are aggregated in the same slave station, but only the output unit or only the input unit is connected. Usually, only one of the information can be acquired in the slave station. A method of directly exchanging information between slave stations connected to each of the output unit and the input unit in correspondence is also conceivable. However, since this is a so-called command transmission method, data is transmitted by a transmission synchronous method. It is difficult to employ in a control / monitor signal transmission system.

  Therefore, the present invention provides a master station connected to the control unit and a plurality of output units, an input unit, and a plurality of slave stations corresponding to the controlled devices are connected by a common data signal line, and data transmission is performed by a transmission synchronization method. In the control / monitoring signal transmission system that is used, even if only one of the output unit or input unit is connected to one slave station, the master station can determine whether the output unit or input unit is faulty An object is to provide a detection method and a slave station terminal used for the detection method.

  The failure detection method according to the present invention is a control / monitoring signal transmission system in which a master station and a plurality of slave stations are connected by a common data signal line, and data is transmitted by a transmission synchronization method, and transmitted to the common data signal line. The transmission signal to be transmitted is provided with a management data area different from the control / monitor data area composed of the control signal data and the monitor signal data. The slave station takes in control data for the reference station or monitoring data transmitted from the reference station from the transmission signal as reference data with a predetermined other station as a reference station. Then, the change direction specified by the reference data (from the change in the rising or falling direction to the change in the change direction specified by the output data to the output unit to which the own station corresponds or the input data from the input unit to which the own station corresponds) Is obtained as an interval time, the interval time is compared with a predetermined threshold, and when the difference from the threshold is within an allowable range, normal and when the difference is smaller than the allowable range, the first failure state, A case where the value exceeds the allowable range is determined as a second failure state, and a signal constituting data indicating the first failure state or the second failure state is superimposed on the management data area.

  As a synchronization method of the transmission synchronization method of the control / monitor signal transmission system to which the failure detection method according to the present invention is applied, for example, a method using a transmission clock generated by the timing generation means of the master station is suitable. . In this case, under the control of the transmission clock, the master station outputs a series of pulse signals as a control signal to the common data signal line according to the value of the control data delivered from the control unit, The data value of the monitoring signal superimposed on the signal for each cycle of the clock from each of the plurality of slave stations is extracted and transferred to the control unit. On the other hand, each of the plurality of slave stations counts the pulses of the series of pulse signals starting from the start signal indicating the start of the series of pulse signals, and when the count value matches the own station address, Data corresponding to the local station is extracted from the pulse signal, and the monitoring signal is superimposed on a series of pulse signals in the same pulse cycle as the clock from which the data corresponding to the local station is extracted, or the count value is When it matches the station address, data corresponding to the own station is extracted from the series of pulse signals or the monitoring signal is superimposed on the series of pulse signals. However, the synchronization method is not limited, and a method suitable for the system design condition may be adopted.

  The management data area includes a management control data area in which data from the master station is superimposed and a management monitoring data area in which data from the slave station is superimposed, and the management monitoring data area from the slave station May be determined as data disconnection of the common data signal line when the data extracted from the management monitoring data area in the master station is “0”.

  The slave station may switch and superimpose a signal constituting data indicating the interval time and a signal constituting other monitoring data in the management data area.

A slave station terminal according to the present invention includes a synchronization means, a reference station input / output change detection means, a local station input / output change detection means, a failure detection means, a reference station reference address setting means, a local station address setting means, a management Monitoring data transmission means is provided.
The synchronization means is connected to a common data signal line to which a master station is connected, and takes transmission synchronization with the master station.
The reference station input / output change detecting means takes a predetermined other station as a reference station, takes control data for the reference station or monitoring data transmitted from the reference station as a reference data from a transmission signal transmitted to the common data signal line, A change in the change direction specified in advance in the reference data is detected and output as a start trigger.
The own station input / output change detecting means detects a change in a change direction designated in advance in the output data for the output unit corresponding to the own station or the input data from the input unit supported by the own station, and this is detected as an end trigger. Output as.
The failure detection means obtains a time from the start trigger to the end trigger as an interval time, compares the interval time with a predetermined threshold value, and is normal when the difference from the threshold value is within an allowable range. The case where it becomes smaller than the allowable range is judged as the first failure state, and the case where it becomes larger than the allowable range is judged as the second failure state.
The reference station reference address setting means sets a reference station address designating the reference station, a type of the reference data, and a change direction of the reference data.
The own station address setting means sets the address of the own station and the change direction of the output data or the input data.
The interval setting means sets an interval value serving as the threshold value.
The management monitoring data transmission unit superimposes a signal constituting data indicating the first failure state or the second failure state on the transmission signal.

  The failure detection unit may switch and output the interval time measurement data and other monitoring data to the management monitoring data transmission unit.

  In the failure detection method according to the present invention, a slave station uses a predetermined other station as a reference station, and takes control data for the reference station or monitoring data transmitted from the reference station from the transmission signal as reference data, thereby specifying changes in the reference data. The time from the change in direction to the change in the designated change direction of the output data for the output unit to which the own station corresponds or the input data from the input unit to which the own station corresponds can be obtained as the interval time. When the input unit and the output unit are operating normally, the interval time changes while maintaining a certain relationship with respect to the operation. Therefore, by comparing this interval time with the first threshold value and the second threshold value, the failure state of the output unit or the input unit can be determined in the slave station. Furthermore, in the slave station, in order to superimpose the data indicating the failure state on the transmission signal transmitted to the common data signal line, in the control / monitoring signal transmission system in which data is transmitted by the transmission synchronization method, the master station side The failure of the output unit and the input unit can be detected.

  Further, if data superposed on the management monitoring data area from the slave station is data other than “0”, the data extracted from the management monitoring data area at the master station is output from the slave station when the data extracted from the management monitoring data area is “0”. It can be said that information is not transmitted to the master station via the common data signal line. Therefore, at that time, it can be determined that the common data signal line is disconnected, and it is possible to detect the disconnection of the common data signal line together with the failure of the input unit or the output unit.

In the slave terminal according to the present invention, the reference station input / output change detecting means uses the predetermined other station as a reference station, and controls data for the reference station or monitoring data transmitted from the reference station as reference data to the common data signal line. It takes in from a transmission signal to be transmitted, detects a change in a change direction specified in advance in the reference data, and outputs this as a start trigger.
The own station input / output change detecting means detects a change in a change direction designated in advance in the output data for the output unit corresponding to the own station or the input data from the input unit supported by the own station, and this is detected as an end trigger. Output as.
The above is a failure detection in which an interval time from a start trigger based on a change in reference data of a predetermined reference station to an end trigger based on a change in data of the own station is compared with a first threshold value and a second threshold value to determine a failure state. Since it is provided with means, it is suitable for the failure detection method according to the present invention.

It is a schematic diagram of a transmission method between a master station and a slave station in an embodiment of a control / monitor signal transmission system employing a failure detection method according to the present invention. 1 is a system configuration diagram showing a schematic configuration of a control / monitor signal transmission system. It is a system configuration | structure figure of a master station. It is a system block diagram of an input slave station. It is a data block diagram of a reference station input / output reference address setting means. It is a data block diagram of a local station address setting means. It is a data block diagram of an interval setting means. It is a system block diagram of a failure detection means. It is a system block diagram of an output slave station. It is a time chart figure which shows the correlation of a signal. It is a time chart figure of a transmission clock signal. It is a schematic diagram of an IDX address data table stored in the master station.

An embodiment of a control / monitor signal transmission system employing the failure detection method according to the present invention will be described with reference to FIGS.
As shown in FIG. 2, the control / monitor signal transmission system includes a single master station 2 connected to the control unit 1 and the common data signal lines DP and DN (hereinafter also referred to as transmission lines), It comprises a plurality of input / output slave stations 4, output slave stations 6 and input slave stations 7 connected to the common data signal lines DP and DN. In FIG. 2, for convenience of illustration, each slave station is shown one by one, but there is no limitation on the type and number of slave stations connected to the common data signal lines DP and DN.

  The input / output slave station 4, the output slave station 6, and the input slave station 7 are provided with a signal output process for the output unit 8 that operates in response to an output instruction from the control unit 1 and an input unit 9 that incorporates input information to the control unit 1. One or both of the input signal processing is performed. The output unit 8 is, for example, an actuator, a (stepping) motor, a solenoid, a solenoid valve, a relay, a thyristor, or a lamp. The input unit 9 is, for example, a reed switch, a micro switch, a push button switch, or a photoelectric switch. And various sensors. The input / output slave station 4 is connected to a controlled device 5 including an output unit 8 and an input unit 9, the output slave station 6 is connected only to the output unit 8, and the input slave station 7 is connected only to the input unit 9. Has been. The output slave station 6 may include an output unit 8 (output unit integrated slave station 80), and the input slave station 7 includes an input unit 9 (input unit integrated slave station). 90).

  The control unit 1 is, for example, a programmable controller, a computer, and the like, and is extracted from the output unit 11 that sends out the control parallel data 13 and the control management parallel data 14, and the monitoring signals from the input / output slave station 4 and the input slave station 7. And an input unit 12 for receiving the first management monitoring parallel data 16 and the second management monitoring parallel data 17 obtained based on the management monitoring data extracted from the monitoring monitoring data 15 and the management monitoring data extracted from the management monitoring signal. . These output unit 11 and input unit 12 are connected to the master station 2. In addition, management judging means 18 for calculating data transmitted from the output unit 11 based on data received from the input unit 12 is provided.

  As shown in FIG. 3, the master station 2 includes an output data unit 21, a management data unit 22, a timing generation unit 23, a master station output unit 24, a master station input unit 25, and an input data unit 26. A control signal (hereinafter referred to as a transmission clock signal) that is connected to the common data signal lines DP and DN and is a series of pulse signals corresponding to the transmission signal of the present invention is connected to the common data signal lines DP and DN. Monitoring signal and management monitoring signal transmitted from the input / output slave station 4, the output slave station 6, or the input slave station 7 (hereinafter referred to as "slave stations 4, 6, 7" when referring to all of them) The monitoring parallel data 15, the first management monitoring parallel data 16 and the second management monitoring parallel data 17 extracted from the above are sent to the input unit 12 of the control unit 1.

  The output data unit 21 delivers the control parallel data 13 from the output unit 11 of the control unit 1 to the master station output unit 24 as serial data.

  The management data unit 22 includes a storage unit 29 that stores an IDX address table in which information on each of the slave stations 4, 6, and 7 is aggregated, and the control management parallel data 14 and the IDX address table from the output unit 11 of the control unit 1. Based on the above, management control data composed of first management control data ISTo and second management control data IDXo, which will be described later, is created and delivered to the master station output unit 24 as serial data. The IDX address table includes data for specifying any one of the input / output slave station 4, the output slave station 6 and the input slave station 7. In this embodiment, the IDX address table includes the data of the slave stations 4, 6, and 7. The start address is used. FIG. 12 shows an example of an IDX address table using the head address.

  As shown in FIG. 12, the station to which the address of # ad0 is assigned has a 1-bit monitoring signal data value, and the data in the IDX address table has a continuous value of # ad0 and # ad1. On the other hand, since the data value of the monitoring signal is 2 bits for the station to which the address of # ad1 is assigned, the pulse of # ad2 is also assigned to the same station as # ad1. Therefore, in the data of the IDX address table, # ad3 is stored as the next value of # ad1. In this embodiment, even if the data value of the monitoring signal is 1 bit, that is, # ad0 is also set as the head address similarly to # ad1. Further, the IDX address table of this embodiment also stores the classification data of the slave stations corresponding to each address. In the example shown in FIG. 10, “1” is assigned to the input slave station 7, “2” is assigned to the output slave station 6, and “3” is assigned to the input / output slave station 4. It is remembered.

  The timing generation unit 23 includes an oscillation circuit (OSC) 31 and a timing generation unit 32. Based on the OSC 31, the timing generation unit 32 generates a timing clock of this system and delivers it to the master station output unit 24.

  The master station output unit 24 includes control data generating means 33 and a line driver 34. Based on the data received from the output data unit 21 and the management data unit 22 and the timing clock received from the timing generation unit 23, the control data generation unit 33 applies a series of data to the common data signal lines DP and DN via the line driver 34. A transmission clock signal is transmitted as a pulse signal.

  As shown in FIG. 1, the transmission clock signal has a control / monitoring data area following the start signal ST and a management data area following the control / monitoring data area. The control / monitoring data area includes control signal data OUTn (n is an integer) sent from the master station 2 and monitoring signal data INn (n is an integer) sent from the input / output slave station 4 or the input slave station 7. Consists of. As shown in FIG. 11, the pulse of the transmission clock signal has a high potential level (+ 24V in this embodiment) in the second half of one cycle and a low potential level (+ 12V in this embodiment) in the first half. The pulse width interval of the first half of the pulse that becomes the level becomes the output data period, and the first half of the pulse that becomes the low potential level also becomes the input data period. The pulse width interval of the low potential level represents the control signal data OUTn, and the presence or absence of the current superimposed on the low potential level represents the monitoring signal data INn. In this embodiment, when one cycle of the transmission clock signal is t0, the pulse width interval of the low potential level is extended from (1/4) t0 to (3/4) t0. As long as it corresponds to the value of each data of the control parallel data 13, the width is not limited and may be determined appropriately. Also, the input data period and the output data period can be appropriately determined. For example, the input data period is set to the first half of the pulse (low potential level) as in this embodiment, and the pulse width interval of the second half of the pulse (high potential level) is set. Alternatively, the output data period may be the first half of the pulse (low potential level) and the second half of the pulse (high potential level) may be the input data period as in this embodiment. Further, the latter half of the pulse (high potential level) may serve as both the output data period and the input data period. The same applies to the case where the second half of one cycle of the transmission clock signal is at a low potential level. In FIG. 1, the upper row shows the output data period, and the lower row shows the input data period.

  The management data area of the transmission clock signal includes a management control data area in which the management control signal transmitted from the master station 2 is superimposed, and management monitoring data in which the management monitoring signal transmitted from the slave stations 4, 6, 7 is superimposed. Consists of regions. The management control data transmitted by the management control signal is composed of the first management control data ISTo and the second management control data IDXo, and is expressed as a pulse width interval of a low potential level, like the control signal data OUTn. Further, the management monitoring data transmitted by the management monitoring signal is composed of the first management monitoring data STi and the second management monitoring data IDXi. Like the monitoring signal data INn, the presence / absence of the current superimposed on the low potential level is determined. expressed. In this embodiment, the first management control data ISTo and the second management control data IDXo are instruction data for specifying the type of data requested to the slave stations 4, 6, 7, or the slave stations 4, 6, 7 Address data for specifying any one of these. On the other hand, the first management monitoring data STi and the second management monitoring data IDXi are data indicating the status of the own station, and data other than “0” is always transmitted as management monitoring data. Details will be described later.

  The start signal ST has the same potential level as the high potential level of the transmission clock signal and is a signal longer than one cycle of the transmission clock signal.

  The master station input unit 25 includes a monitoring signal detection unit 35 and a monitoring data extraction unit 36. The monitoring signal detection means 35 detects the monitoring signal and the management monitoring signal sent from the slave stations 4, 6, and 7 via the common data signal lines DP and DN. As described above, the data values of the monitoring signal and the management monitoring signal are represented by the presence / absence of a current superimposed on the low potential level. After the start signal ST is transmitted, first, the input / output slave station 4 or the input A monitoring signal is sequentially received from each of the slave stations 7, and subsequently, a management monitoring signal is received from any one of the slave stations 4, 6, and 7. Data of the monitoring signal and the management monitoring signal is extracted by the monitoring data extracting unit 36 in synchronization with the signal of the timing generating unit 32. The monitoring signal data is sent to the input data unit 26 as serial input data 37. Management monitoring data 39 extracted from the management monitoring signal is also sent to the input data unit 26.

  The input data unit 26 converts the serial input data 37 received from the master station input unit 25 into parallel (parallel) data, and sends the parallel data to the input unit 12 of the control unit 1. Further, the management monitoring data 39 received from the master station input unit 25 is separated into the first management monitoring parallel data 16 and the second management monitoring parallel data 17 and sent to the input unit 12.

  The input slave station 7 corresponds to the slave station terminal of the present invention. As shown in FIG. 4, the transmission receiving means 41, the management control data extracting means 42, the address extracting means 43, the own station address setting means 44, the management Monitoring data transmission means 45, monitoring data transmission means 46, own station input / output change detection means 47, reference station input / output reference address setting means 48, reference station input / output change detection means 49 failure detection means 50, interval setting means 71 and input means 72 Is provided. Further, a first disconnection detecting means 49 disposed between the slave station input unit 70 and the input unit 9 is provided. The input slave station 7 of this embodiment includes an MCU that is a microcomputer control unit as an internal circuit, and this MCU functions as the slave station input unit 70. Calculations and storages necessary for the processing are executed using the CPU, RAM, and ROM included in the MCU, and the CPU, RAM, and ROM in the processing of each of the above-described means constituting the slave station input unit 70 The relationship is omitted for convenience of explanation.

  The output slave station 6 is another embodiment of the slave station terminal of the present invention. Like the input slave station 7, the output slave station 6 includes an MCU which is a microcomputer control unit as an internal circuit, and this MCU is a slave station. It functions as the output unit 60. Similar to the MCU of the slave station input unit 70, calculations and storages necessary for the processing of the output slave station 6 are executed using the CPU, RAM, and ROM included in this MCU.

  Both the output unit 8 and the input unit 9 that are in a corresponding relationship are connected to the input / output slave station 4. Similarly to the output slave station 6 and the input slave station 7, the input / output slave station 4 includes an MCU that is a microcomputer control unit as an internal circuit, and this MCU functions as the slave station input / output unit 40. It has become a thing. Similar to the MCU of the slave station output unit 60 and the MCU of the slave station input unit 70, calculations and storages necessary for the processing of the input / output slave station 4 are performed using the CPU, RAM, and ROM included in this MCU. It is supposed to be executed.

  The transmission receiving means 41 of the input slave station 7 receives the transmission clock signal transmitted to the common data signal lines DP and DN, and receives them as management control data extracting means 42, address extracting means 43, and management monitoring data transmitting means 45. To hand over. The management control data extracting unit 42 extracts management control signal data from the management data area of the transmission clock signal, and delivers them to the failure detection unit 50. On the other hand, the address extracting means 43 counts pulses starting from the start signal ST indicating the start of the transmission clock signal, and the count value is set to the own station address data (the own station address described later) set by the own station address setting means 44. (SADR) at the timing that coincides with the monitoring data transmission means 46, and at the timing when the count value coincides with the reference station input / output reference address (reference station input / output reference address RADR described later), the designated signal (input / output described later). The signal designated by the designated value RD), that is, the control signal for the reference station or the monitoring signal transmitted from the reference station is delivered to the reference station input / output change detecting means 49.

  The monitoring data transmitting unit 46 sets the base current of the transistor TR to “on” or “off” based on the serial data delivered from the input unit 72 at the timing when the control signal is delivered from the address extracting unit 43. When the base current is “on”, the transistor TR is turned “on”, and a current signal as a monitoring signal is output to the common data signal lines DP and DN. In this embodiment, as shown in FIG. 12, when the data value of the monitoring data is “1”, it is expressed by passing a current (for example, 30 mA) of a predetermined value Ith or more. Therefore, for example, the monitoring data at addresses 0 (# ad0), 1 (# ad1), 2 (# ad2), and 3 (# ad3) of the signal shown in FIG. It represents 0 ”,“ 1 ”,“ 0 ”. The data delivered from the input unit 47 to the monitoring data transmission unit 47 is based on the output logic data from the input unit 9.

  The management monitoring data transmission means 45 counts pulses starting from the start signal ST of the transmission clock signal, and obtains the timing of the management data area. Then, based on the data delivered from the failure detection means 50, the base current of the transistor TR is output, and a current signal which is a management monitoring signal is output to the common data signal lines DP and DN.

  As shown in FIG. 5, the local station address setting unit 44 delivers the local station address SADR to the address extraction unit 43 and the failure detection unit 50, and also indicates an end change direction instruction value indicating the change direction of input data from the input unit 9. The ET is delivered to the local station input / output change detecting means 47.

  As shown in FIG. 6, the reference station input / output reference address setting means 48 passes the reference station input / output reference address RADR and the input / output designation value RD for specifying the type of signal to be fetched to the address extraction means 43, and controls the control signal or The start change direction instruction value ST indicating the change direction of the monitoring signal transmitted from the reference station is delivered to the reference station input / output change detecting means 49.

  The own station input / output change detecting means 47 uses the data delivered from the input means 72 as the own station data, and the own station data is defined by the end change direction instruction value ET delivered from the own station address setting means 44. When the direction changes to the same direction, the end trigger is handed over to the failure detection means 50.

  The reference station input / output change detecting means 49 uses the signal data delivered from the address extracting means 43 as reference data, and the reference data is defined by the start change direction instruction value ST delivered from the reference station input / output reference address setting means 48. When the direction is changed in the same direction as the change direction, the start trigger is delivered to the failure detection means 50.

  As shown in FIG. 7, the interval setting unit 71 delivers two interval values TM1 and TM2 that are threshold values for failure determination in the failure detection unit 50 to the failure detection unit 50. The interval values TM1 and TM2 stored in the interval setting means 71 can be changed by downloading from the control unit 1 side.

  As shown in FIG. 8, the failure detection means 50 includes an ISTo extraction means 51, an IDXo extraction means 52, a slave station address designation detection means 53, a TM measurement means 55, an encoding means 56, and a data addition means 57. Yes.

  The ISTo extraction means 51 extracts the first management control data ISTo from the management control signal data delivered from the management control data extraction means 42 and delivers it to the slave station address designation detection means 53. Further, the IDXo extraction unit 52 extracts the second management control data IDXo from the management control signal data delivered from the management control data extraction unit 42, and delivers it to the slave station address designation detection unit 53. The own station address data is delivered from the own station address setting means 44 to the slave station address designation detecting means 53.

  The slave station address designation detecting means 53 compares the second management control data IDXo with the data value of the local station address, and if they match, the predetermined address data is encoded by the encoding means 56 or data according to the first management control data ISTo. Delivered to the adding means 57. That is, when the first management control data ISTo is data instructing failure detection based on the interval time, the failure detection command data is delivered to the encoding means 56 and the data adding means 57.

  The TM measuring means 55 includes a start trigger delivered from the reference station input / output change detecting means 49, an end trigger delivered from the own station input / output change detecting means 47, and a threshold (first interval) delivered from the interval setting means 71. Failure detection processing is performed based on the value TM1 and the second interval value TM2). That is, as shown in FIG. 10, the time difference from the input time To of the start trigger indicating the change of the reference data to the input time Tn of the end trigger indicating the change of the local station data is the first interval value TM1 and the second interval. It is determined whether the value TM2 is within an allowable range set in advance. When the time difference is within the allowable range (the first interval value TM1 or more and the second interval value TM2 or less), information indicating a normal state is displayed, and the time difference is smaller than the first interval value TM1 (FIG. 10). In FIG. 10, when the end trigger time is Ts), the information indicating the first failure state is displayed. When the second interval value TM2 is exceeded (in FIG. 10, when the end trigger time is Tl), the second failure state is displayed. The indicated information is output to the encoding means 56. Further, the time difference data is delivered to the data adding means 57.

  As described above, the start trigger is delivered to the failure detection means 50 when the data changes in the same direction as the change direction defined by the start change direction instruction value ST and the end trigger is defined by the end change direction instruction value ET. Therefore, the failure detection means 50 can cope with any change in the reference data and the local station data by setting the start change direction instruction value ST and the end change direction instruction value ET. In FIG. 10, (a) shows the case where both the reference data and the local station data change from “0” to “1”, and (b) shows the local data from “0” to “1”. (C) shows the case where the reference data changes from “1” to “0”, and the local station data changes from “0” to “1”. The case where both the reference data and the local station data change from “1” to “0” is shown.

  Based on the first management control data ISTo delivered from the slave station address designation detection means 53, the encoding means 56 outputs information indicating the normal state, the first failure state and the second failure state outputted from the TM measurement means 55. The data is converted into predetermined code data and delivered to the management monitoring data transmission means 46.

  Based on the first management control data ISTo delivered from the slave station address designation detecting means 53, the data adding means 57 converts the time difference data delivered from the TM measuring means 55 into the second management monitoring data following the first management monitoring data STi. It is handed over to the management monitoring data transmission means 46 as IDXi.

  At this time, a value other than “0” is adopted for the first management monitoring data STi delivered to the management monitoring data transmission means 46, that is, the code data indicating the normal state, the first failure state, and the second failure state. . Therefore, data other than “0” is transmitted as management monitoring data. That is, when the management monitoring data is “0”, it can be said that the information output from the input slave station 7 is not transmitted to the master station via the common data signal lines DP and DN. Therefore, at that time, it can be determined that the common data signal lines DP and DN are disconnected.

  The MCU of the slave station output unit 60 is configured such that the monitoring data transmission unit 46 in the MCU of the slave station input unit 70 is the control data extraction unit 81 and the input unit 72 is the output unit 82. The control data extracting unit 81 extracts a data value from the control data signal delivered from the address extracting unit 43 and delivers it to the output unit 82 as serial data. The data value extracted from the control data signal is also delivered to the own station input / output change detecting means 47 as own station data. The output unit 82 converts the serial data delivered from the control data extraction unit 81 into parallel data, outputs the parallel data to the output unit 8, and causes the output unit 8 to perform a predetermined operation. The other configuration of the MCU of the slave station output unit 60 is the same as that of the MCU of the slave station input unit 70, and thus the description thereof is omitted.

Next, the procedure of the failure detection method in the control / monitoring signal transmission system having the above configuration will be described.
The control unit 1 outputs management control parallel data 14 for instructing the failure detection of the output unit 8 or the input unit 9 to the master station 2 at a timing set appropriately or by an arbitrary input instruction by the user. Receiving this, the master station 2 receives the first management control data ISTo requesting the presence / absence information on the detection of the disconnection of the input signal line, and the second management designating one of the data groups stored in the IDX address table. Control data IDXo is output. The IDX address data table shown in FIG. 12 has already been created in the management data section 22 of the master station 2, and a transmission composed of a start signal ST, a control / monitoring data area and a management data area following the start signal ST. For each cycle, the start address assigned to all of the input slave stations 7 is sequentially specified by the second management control data IDXo.

  The designation of data in the IDX address table by the second management control data IDXo is in accordance with the table number. That is, first, the index address data (# ad0) of the table number 1 is selected and output as the second management control data IDXo. Then, every transmission cycle, the slave station classification data is sequentially changed to head address data corresponding to each table number having “1”. However, the order in which the data of the IDX address table is designated by the second management control data IDXo is not limited, and may be in accordance with the priority order by function, for example.

  Based on the data indicating the first failure state, the second failure state, or the normal state output from the failure detection means 50 when the second management control data IDXo matches the own station address, the input slave station 7 A management monitoring signal composed of data indicating normality is superimposed on the management monitoring data area. In response to this, the master station 2 extracts management monitoring data from the management monitoring signal and delivers it to the control unit 1.

  In the control unit 1, predetermined processing is executed according to the contents of the first management monitoring parallel data 16. Specifically, if the first management monitoring parallel data 16 indicates an abnormality, an abnormality display is performed. If the management monitoring data is “0”, it is determined that the common data signal lines DP and DN are disconnected, and a message to that effect is displayed.

  Through the above procedure, the control unit 1 can grasp the presence or absence of connection abnormality or internal circuit abnormality for each of the input units 9 corresponding to the input slave station 7.

  The first interval value TM1 and the second interval value TM2, which are threshold values, can be appropriately changed from the control unit side. In that case, the data indicating that the first interval value TM1 and the second interval value TM2 are changed, and the changed first interval value TM1 and the second interval value TM2 are superimposed on the management control data area and input. These may be extracted on the slave station 7 and the output slave station 8 side.

  In this control / monitor signal transmission system, it is possible to monitor data different from the measurement data of the interval time. In that case, the gate means 62 indicated by an imaginary line in FIG. 8 is provided, and the data 63 to be monitored is input to the gate means 62, and the measurement data of the interval time is received from the slave station address designation detecting means 53. Command data for switching the monitoring data 63 is output. Then, by transmitting the input monitor command data as the first management control data ISTo from the master station 2 to the corresponding input / output slave station 4, output slave station 6, and input slave station 7, TM measurement is performed via the gate means 62. Since the measurement data of the interval time of the means 55 and the monitoring data 63 are switched and output as management monitoring data, this can be grasped on the control unit 1 side.

1 Control Unit 2 Master Station 4 Input / Output Slave Station 5 Controlled Device 6 Output Slave Station 7 Input Slave Station 8 Output Unit 9 Input Unit 11 Output Unit 12 Input Unit 13 Control Parallel Data 14 Management Control Parallel Data 15 Monitoring Parallel Data 16 One management monitoring parallel data 17 Second management monitoring parallel data 18 Management judging means 21 Output data section 22 Management data section 23 Timing generating section 24 Master station output section 25 Master station input section 26 Input data section 29 Storage means 31 OSC (oscillation circuit )
32 Timing generation means 33 Control data generation means 34 Line driver 35 Monitoring signal detection means 36 Monitoring data extraction means 37 Input data 39 Management monitoring data 40 Slave station input / output unit 41 Transmission reception means 42 Management control data extraction means 43 Address extraction means 44 Local station address setting means 45 Management monitoring data transmission means 46 Monitoring data transmission means 47 Local station input / output change detection means 48 Reference station input / output reference address setting means 49 Reference station input / output change detection means 50 Fault detection means 51 ISTo extraction means 52 IDXo extraction Means 53 Slave station address designation detection means 55 TM measurement means 56 Encoding means 57 Data addition means 60 Slave station output section 62 Gate means 63 Monitoring data 70 Slave station input section 71 Interval setting means 72 Input means 80 Output section integrated slave station 81 Control data extraction It means 82 output unit 90 input unit integrally Katako station TR transistor

Claims (5)

In a control / monitor signal transmission system in which a master station and a plurality of slave stations are connected by a common data signal line and data is transmitted by a transmission synchronization method.
The transmission signal transmitted to the common data signal line is provided with a management data area different from the control / monitor data area composed of control signal data and monitoring signal data,
The slave station takes a predetermined other station as a reference station, takes control data for the reference station or monitor data transmitted from the reference station from the transmission signal as reference data,
The time from the change in the specified change direction of the reference data to the change in the specified change direction of the output data to the output unit corresponding to the own station or the input data from the input unit to which the own station corresponds is obtained as an interval time. The interval time is compared with a predetermined threshold value, when the difference from the threshold value is within an allowable range, normal and when the difference is smaller than the allowable range, the first failure state, and when the larger than the allowable range A failure detection method characterized by determining a second failure state and superimposing a signal constituting data indicating the first failure state or the second failure state in the management data area.   The management data area includes a management control data area in which data from the master station is superimposed and a management monitoring data area in which data from the slave station is superimposed, and the management monitoring data area from the slave station The data superimposed on the data is determined as data other than “0”, and when the data extracted from the management monitoring data area in the master station is “0”, it is determined that the common data signal line is disconnected. Disconnection detection method.   The disconnection detection method according to claim 1 or 2, wherein the slave station switches and superimposes a signal constituting data indicating the interval time and a signal constituting other monitoring data in the management data area. A synchronization means connected to the common data signal line to which the master station is connected, and for synchronizing transmission with the master station;
Taking a predetermined other station as a reference station, control data for the reference station or monitoring data transmitted from the reference station is taken as a reference data from a transmission signal transmitted to the common data signal line, and the reference data changes in advance Reference station input / output change detection means for detecting a change in direction and outputting this as a start trigger,
Local station input / output change detection means for detecting a change in a predetermined change direction of output data for an output section to which the local station corresponds or input data from an input section to which the local station corresponds, and outputting this as an end trigger When,
The time from the start trigger to the end trigger is obtained as an interval time, the interval time is compared with a predetermined threshold value, and when the difference from the threshold value is within an allowable range, normal and smaller than the allowable range A failure detection means for determining that the first failure state and a second failure state when the difference is greater than the allowable range;
A reference station reference address setting means for setting a reference station address for designating the reference station, a type of the reference data, and a change direction of the reference data;
Own station address setting means for setting the address of the own station and the change direction of the output data or the input data;
Interval setting means for setting an interval value as the threshold;
A slave station terminal comprising management monitoring data transmission means for superimposing a signal constituting data indicating the first failure state or the second failure state on the transmission signal. 5. The slave station terminal according to claim 4, wherein the failure detection means switches and outputs interval time measurement data and other monitoring data to the management monitoring data transmission means.

Images