CN111179462B - PLC operation data recording method based on multi-master station communication mode - Google Patents
PLC operation data recording method based on multi-master station communication mode Download PDFInfo
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- CN111179462B CN111179462B CN201911230105.5A CN201911230105A CN111179462B CN 111179462 B CN111179462 B CN 111179462B CN 201911230105 A CN201911230105 A CN 201911230105A CN 111179462 B CN111179462 B CN 111179462B
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- G—PHYSICS
- G07—CHECKING-DEVICES
- G07C—TIME OR ATTENDANCE REGISTERS; REGISTERING OR INDICATING THE WORKING OF MACHINES; GENERATING RANDOM NUMBERS; VOTING OR LOTTERY APPARATUS; ARRANGEMENTS, SYSTEMS OR APPARATUS FOR CHECKING NOT PROVIDED FOR ELSEWHERE
- G07C3/00—Registering or indicating the condition or the working of machines or other apparatus, other than vehicles
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- G—PHYSICS
- G08—SIGNALLING
- G08C—TRANSMISSION SYSTEMS FOR MEASURED VALUES, CONTROL OR SIMILAR SIGNALS
- G08C17/00—Arrangements for transmitting signals characterised by the use of a wireless electrical link
- G08C17/02—Arrangements for transmitting signals characterised by the use of a wireless electrical link using a radio link
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L43/00—Arrangements for monitoring or testing data switching networks
- H04L43/08—Monitoring or testing based on specific metrics, e.g. QoS, energy consumption or environmental parameters
- H04L43/0805—Monitoring or testing based on specific metrics, e.g. QoS, energy consumption or environmental parameters by checking availability
- H04L43/0811—Monitoring or testing based on specific metrics, e.g. QoS, energy consumption or environmental parameters by checking availability by checking connectivity
Abstract
The embodiment of the invention provides a PLC operation data recording method based on a multi-master-station communication mode, which comprises the following steps: periodically receiving data frames fed back by a target PLC, wherein the data frames are used as channel state monitoring data frames; and if the channel state response data frame is received within the preset time, determining that the data channel between the target PLC and the target PLC is in a connection state, and reading and recording operation data from the target PLC according to a multi-master-station communication mode. The PLC operation data recording method based on the multi-master-station communication mode provided by the embodiment of the invention realizes the tamper-proof recording and transmission of key operation accumulated data even in places without network coverage; on the basis of not changing the original program of the PLC, the functions of inquiring, accumulating, counting and the like of internal data can be realized, and the internal data can be stored in a CPU type IC card which is copy-proof and tamper-proof.
Description
Technical Field
The invention relates to the technical field of industrial automatic control, in particular to a PLC operation data recording method based on a multi-master-station communication mode.
Background
In the process of automatically controlling the operation of equipment, parameters such as the live time, the large current (more than a certain current value is regarded as heavy load, such as 5A) operation time, the maximum current value and the like of a Programmable Logic Controller (PLC) and a control object of the PLC are recorded and managed in many application occasions, and the method has important reference values for the maintenance and the like of the equipment.
In the prior art, an online monitoring technology is adopted to record and manage the operation data of the PLC in most scenes, and the online monitoring technology is to continuously or regularly monitor the operation data of the monitored equipment under the condition that the monitored equipment is in operation, and is generally performed automatically. The detector can synchronously monitor the monitored equipment through the online monitoring platform. However, the method is suitable for fixed-position installation equipment, or can be used for online monitoring in a wireless or wired network coverage mode, and forms a record history data record. Moreover, the method also needs to configure a computer running platform required by monitoring and configuration software.
However, in practical applications, the leasing of a device with a PLC as a core has become a way of device sharing, and for such a scenario, there is usually no network coverage condition, and a leaser and a lessee pay much attention to the operation data of the PLC device, and a corresponding communication network including an upper computer is specially constructed to monitor the use condition of the PLC device, and it is necessary to modify a source program of the PLC device, purchase configuration software, construct the communication network, and even modify a source program of the PLC in the device, so that the system is very complex, many lessees do not have such a secondary development capability, and even such a secondary development capability, the cost is very high, and therefore, a simple PLC operation data recording system capable of preventing tampering is urgently needed.
Disclosure of Invention
The embodiment of the invention provides a PLC operation data recording method based on a multi-master-station communication mode, which is used for solving the technical problems in the prior art.
In order to solve the above technical problem, in one aspect, an embodiment of the present invention provides a PLC operating data recording method based on a multi-master-station communication mode, including:
periodically receiving equipment searching data frames sent by a target PLC, and receiving data frames fed back by the target PLC after responding, wherein the data frames are used as channel state monitoring data frames; the channel state monitoring data frame is used for indicating the target PLC to feed back a channel state response data frame within a preset time;
if the channel state response data frame is not received within the preset time, determining that a data channel between the target PLC and the target PLC is in a disconnected state; and if the channel state response data frame is received within the preset time, determining that the data channel between the target PLC and the target PLC is in a connection state, and reading and recording operation data from the target PLC according to a multi-master-station communication mode.
Further, after determining that the data channel between the target PLC and the target PLC is in the disconnected state, the method further includes:
if the last period also monitors that the data channel between the PLC and the target PLC is in a disconnection state, accumulating the disconnection time between the PLC and the target PLC for one period;
and if the data channel between the PLC and the target PLC is in a connection state during the last period, not accumulating the disconnection time between the PLC and the target PLC.
Further, after determining that the data channel between the target PLC and the target PLC is in a connected state, the method further includes:
if the last period also monitors that the data channel between the PLC and the target PLC is in a connection state, accumulating the connection time between the PLC and the target PLC for one period;
and if the data channel between the PLC and the target PLC is in a disconnected state during the last period, not accumulating the connection time between the PLC and the target PLC.
Further, after the operating data is read from the target PLC and recorded according to the multi-master-station communication mode, the method further includes:
receiving data copying request information sent by a non-contact CPU card, wherein the data copying request information carries a copied data authority identifier;
and if the copy data authority identification passes the verification, writing the recorded running data into a non-contact CPU card.
Further, after determining that the data channel between the target PLC and the target PLC is in a connected state, the method further includes:
reading clock data from the target PLC according to a multi-master station communication mode;
and carrying out clock synchronization with the target PLC.
Further, the operation data at least includes one of switching value input point data, switching value output point data, analog value input point data, analog value output point data, external variables read through the communication interface, and external variables sent to other devices.
On the other hand, an embodiment of the present invention provides a PLC operating data recording apparatus based on a multi-master-station communication mode, including:
the transmitting module is used for periodically receiving equipment searching data frames transmitted by the target PLC, responding, and receiving data frames fed back by the target PLC, wherein the data frames are used as channel state monitoring data frames; the channel state monitoring data frame is used for indicating the target PLC to feed back a channel state response data frame within a preset time;
the recording module is used for determining that a data channel between the target PLC and the recording module is in a disconnected state if the channel state response data frame is not received within the preset time; and if the channel state response data frame is received within the preset time, determining that the data channel between the target PLC and the target PLC is in a connection state, and reading and recording operation data from the target PLC according to a multi-master-station communication mode.
In another aspect, an embodiment of the present invention provides an electronic device, including: a memory, a processor, and a computer program stored on the memory and executable on the processor, the processor implementing the steps of the above method when executing the computer program.
In yet another aspect, the present invention provides a non-transitory computer readable storage medium, on which a computer program is stored, which when executed by a processor implements the steps of the above method.
The PLC operation data recording method based on the multi-master-station communication mode provided by the embodiment of the invention realizes the tamper-proof recording and transmission of key operation accumulated data even in places without network coverage; on the basis of not changing the original program of the PLC, the functions of inquiring, accumulating, counting and the like of internal data can be realized, and the internal data can be stored in a CPU type IC card which is copy-proof and tamper-proof.
Drawings
Fig. 1 is a schematic diagram of a PLC operation data recording method based on a multi-master-station communication mode according to an embodiment of the present invention;
fig. 2 is a schematic diagram of a PLC operation data recording device based on a multi-master-station communication mode according to an embodiment of the present invention;
fig. 3 is a schematic structural diagram of an electronic device according to an embodiment of the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments of the present invention without making any creative effort, shall fall within the protection scope of the present invention.
The multi-master-station communication mode is a communication mode that all devices in a network are master stations, and data transmission is carried out between the master stations by adopting an active protocol, so that data frames are continuously transmitted no matter whether other machines access the network, and the machines in the network can know the existence of the machines. The multi-point interface protocol is a common protocol adopted by a multi-master station communication mode.
Multi Point Interface (MPI) is a protocol developed by siemens for the privacy of communications between PLCs. MPI communication is a simple and economic communication mode which can be adopted when the communication speed requirement is not high and the communication data volume is not large. The MPI communication can use PLC S7-200/300/400, operation panel TP/OP and upper computer MPI/PROFIBUS communication card, such as CP5512/CP5611/CP5613, etc. to exchange data. The communication rate of the MPI network is 19.2 Kbps-12 Mbps, the maximum communication distance can be up to 32 nodes, and the maximum communication distance is 50m, but the length can be extended through the repeater.
Similarly, in a network consisting of more than 1 Siemens S7-200 series of PLCs, there are cases where one PLC of the S7-200 series acts as a master station and others act as slave stations. For example, some PLCs of siemens define communication PORTs with special register words SMB30 (for PORT0, PORT 0) and SMB130 (for PORT1, PORT1 if PORT 1). The communication mode is determined by the lowest two bits of the control word and can be defined as the PPI slave mode (default value) and the PPI master mode.
The PPI protocol is a communication protocol developed by Siemens for the full series of S7-200. PPI is a master-slave protocol, where the master sends a request to the slave, which responds. The slave station does not actively send information, but just waits for the request of the master station and responds. And the PLC working in the master station mode also responds to commands sent by other master stations (including the startup and shutdown system circuit board) and responds.
In the embodiment of the present invention, when data needs to be acquired from the target PLC, a handshake process needs to be completed after mutual confirmation interaction of data frames (similar to broadcast data frames) periodically sent by the target PLC is responded, and then a subsequent communication process can be implemented.
Some of the currently used IC cards have been cracked, and the data stored therein have been cracked by a mature method and have been widely spread in some occasions. The non-contact CPU card is also called smart card, and the integrated circuit in the card has a microprocessor CPU, a storage unit (including a random access memory RAM, a program memory rom (flash), a user data memory EEPROM) and a chip operating system COS. The CPU card equipped with COS is equivalent to a microcomputer, and has not only a data storage function but also functions of command processing, data security protection, and the like. In the aspect of security, compared with a non-contact IC card, the non-contact CPU card has an independent CPU processor and a chip operating system, so that various different application requirements can be supported more flexibly, a data exchange flow can be designed more safely, and no technology and method for cracking and tampering exist at present. Is an extremely safe storage carrier.
The embodiment of the invention provides a PLC operation data recording method based on a multi-master-station communication mode. On the basis of not changing the original program of the PLC, the purposes of inquiring, accumulating, counting and the like of the on-off record of the channel between the circuit board of the statistical recording system and the PLC-CPU, the on-off input quantity, the on-off output quantity, the analog input quantity and the analog output quantity in the PLC are realized, and the on-off record is stored in the anti-copy and anti-tampering CPU IC card.
Fig. 1 is a schematic diagram of a PLC operation data recording method based on a multi-master-station communication mode according to an embodiment of the present invention, and as shown in fig. 1, the embodiment of the present invention provides a PLC operation data recording method based on a multi-master-station communication mode, where the method includes:
step S101, periodically receiving equipment search data frames sent by a target PLC, and after responding, receiving data frames fed back by the target PLC, wherein the data frames are used as channel state monitoring data frames; the channel state monitoring data frame is used for indicating the target PLC to feed back a channel state response data frame within a preset time.
Step S102, if the channel state response data frame is not received within the preset time, determining that a data channel between the target PLC and the target PLC is in a disconnected state; and if the channel state response data frame is received within the preset time, determining that the data channel between the target PLC and the target PLC is in a connection state, and reading and recording operation data from the target PLC according to a multi-master-station communication mode.
Specifically, the method in the embodiment of the present invention will be described below by taking siemens PLC as an example.
On a DB9 serial interface of a Siemens PLC-CPU, an onboard MPI protocol serial port of a statistical recording system circuit board is connected through a first serial port connecting wire, an onboard non-contact CPU card reader-writer interface of the statistical recording system circuit board is connected through a second serial port connecting wire, and a non-contact CPU card reading-writing coil is installed on the onboard non-contact CPU card reader-writer. A central processing unit CPU, a Flash memory, a random access memory RAM, a power supply processing unit and a clock battery are particularly arranged on the circuit board of the statistical recording system; in addition, a non-contact read-write CPU card host is also configured, and the non-contact read-write CPU card host also comprises a non-contact CPU card upper computer reader-writer.
In particular, the common baud rates are 300bps, 600bps, 1200bps, 2400bps, 4800bps, 9600bps, 19200bps, 38400bps, 43000bps, 56000bps, and,
Standard baud rates of 57600bps, 115200bps and the like can be set for common desktop baud rates with better performance, but the highest baud rate is only 115200 bps; the recommended baud rate of the Siemens MPI interface is as high as 187500bps, even 12Mbit/s, and the baud rate adopted by the onboard MPI protocol serial port of the statistical recording system circuit board is a high baud rate serial port, so that correct communication with the Siemens PLC-CPU can be ensured.
In order to protect the safety of the read-write process of the non-contact CPU card, the circuit protection function is started for the read-write command of the non-contact CPU card, external unauthorized cracking equipment cannot obtain real transmitted data information, and even if technical means are adopted, the transmission data is intercepted and encrypted, so that the information safety of the data in the data transmission process between the non-contact CPU card and a machine-mounted non-contact CPU card reader-writer or a machine-mounted non-contact CPU card reader-writer on the non-contact CPU card is ensured.
The Siemens MPI protocol is selected to control the Siemens PLC-CPU, programming is not needed, and the control program in the Siemens PLC-CPU and the statistical recording system circuit board data transmission scheme is not needed to be changed, and the Siemens PLC-CPU and the statistical recording system circuit board data transmission scheme is as follows: depending on the characteristics of the siemens MPI device, in which state (RUN or STOP) the siemens PLC-CPU is, once it is powered up, it will send out data frames continuously and respond to the correct data frames received. And the Siemens PLC-CPU sends a data frame to a statistical recording system circuit board through a DB9 serial interface, a first serial port connecting line and an onboard MPI protocol serial port of the statistical recording system circuit board. And the data frame written to the Siemens PLC-CPU is transmitted to the Siemens PLC-CPU from the statistical recording system circuit board and an onboard MPI protocol serial port of the statistical recording system circuit board through a first serial port connecting wire and a DB9 serial interface.
The state monitoring and recording object of the communication channel between the Siemens PLC-CPU and the statistical recording system circuit board is the communication channel between the statistical recording system circuit board and the Siemens PLC-CPU, and the communication channel is formed by connecting an onboard MPI protocol serial port of the statistical recording system circuit board through a first serial port connecting wire and a DB9 serial port.
The state monitoring and recording of a communication channel between the Siemens PLC-CPU and the statistical recording system circuit board are divided into two directions: the first direction is from Siemens PLC-CPU to statistics recording system circuit board data channel, the second direction is from statistics recording system circuit board to Siemens PLC-CPU data channel.
According to the on-off judgment scheme of the first direction channel, if the statistics recording system circuit board does not receive the data frame sent by the Siemens PLC-CPU for a short time (such as 0.5 second, 1 second and the like), a receiving channel from the Siemens PLC-CPU to the statistics recording system circuit board is judged to be in an off state; otherwise, the channel is judged to be in a connection state.
The scheme for monitoring, recording and counting the channel state accumulation time and the on-off switching time of the first direction according to the channel is as follows: the statistical recording system circuit board is fixed in time interval (such as 1 second, 1 minute or other values), whether a data channel from the Siemens PLC-CPU to the statistical recording system circuit board is in an open state or a connected state in a first direction is judged, and the data channel is stored in a certain storage space of the random access memory RAM, and the processing method comprises the following four conditions.
In the first case: if the connection state of the circuit board data channel from the Siemens PLC-CPU to the statistical recording system is the same as the connection state of the circuit board data channel of the last time, the running time length of the storage space in the Siemens PLC-CPU is accumulated for a fixed time interval (such as 1 second, 1 minute or other values) and written into a Flash storage.
In the second case: if the data channel from the Siemens PLC-CPU to the statistical recording system circuit board is in the disconnection state which is the same as the disconnection state at the last time, the disconnection time length of the storage space in the Siemens PLC-CPU is accumulated for the fixed time interval (such as 1 second, 1 minute or other values) at this time, and the fixed time interval is written into a Flash storage.
In the third case: if the data channel from the Siemens PLC-CPU to the statistical recording system circuit board is in a disconnected state and is in a connected state last time, the unobstructed/interrupted time length of the storage space in the Siemens PLC-CPU is not accumulated for the fixed time interval and is not written into a Flash storage, but the current time is recorded as the interrupted time of the channel and is written into the Flash storage.
In a fourth case: if the data channel from the Siemens PLC-CPU to the statistical recording system circuit board is in a connection state different from a disconnection state last time, the unobstructed/interrupted time length of the storage space in the Siemens PLC-CPU is not accumulated for a fixed time interval (such as 1 second, 1 minute or other numerical values) of the time, and is not written into a Flash storage, but the time of the time is recorded as the recovery time of the channel, and is written into the Flash storage.
And the on-off judgment scheme of the second direction channel is as follows: the statistical recording system circuit board sends a data frame to the Siemens PLC-CPU according to an MPI protocol, and receives a correct data frame responded by the Siemens PLC-CPU in a short time (such as 0.5 second, 1 second and the like), and then the channel from the statistical recording system circuit board to the Siemens PLC-CPU is judged to be in a connection state; otherwise, the channel is judged to be in an off state.
The scheme for monitoring, recording and counting the channel state accumulation time and the on-off switching time of the channel in the second direction is as follows: the statistical recording system circuit board is fixed in time interval (such as 1 second, 1 minute or other values), whether the circuit board from the statistical recording system circuit board to the Siemens PLC-CPU is in an off state or a connected state is judged, and the circuit board is stored in a certain storage space of the random access memory RAM, and the following four conditions are divided.
In the first case: if the connection state from the statistical recording system circuit board to the Siemens PLC-CPU data channel is the same as the connection state at the last time, the running time length of the storage space in the statistical recording system circuit board is accumulated for a fixed time interval (such as 1 second, 1 minute or other values) and written into a Flash storage.
In the second case: if the data channel from the statistical recording system circuit board to the Siemens PLC-CPU is in the disconnection state which is the same as the disconnection state at the last time, the disconnection time length of the storage space in the statistical recording system circuit board is accumulated for the fixed time interval, and the fixed time interval is written into a Flash storage.
In the third case: if the data channel from the statistical recording system circuit board to the Siemens PLC-CPU is in a disconnected state and is different from the last connection state, the unobstructed/interrupted time length of the storage space in the statistical recording system circuit board is not accumulated for the fixed time interval (such as 1 second, 1 minute or other values) of the time, and is not written into the Flash storage, but the time of the time is recorded as the interrupted time of the channel, and is written into the Flash storage.
In a fourth case: if the connection state from the statistical recording system circuit board to the Siemens PLC-CPU data channel is different from the disconnection state at the last time, the unobstructed/interrupted time length of the storage space in the statistical recording system circuit board is not accumulated for the fixed time interval (such as 1 second, 1 minute or other numerical values) at this time, and is not written into the Flash storage, but the time at this time is recorded as the recovery time of the channel, and is written into the Flash storage.
When in actual use, firstly, the non-contact CPU card is initialized, and the scheme is as follows: firstly, judging whether useful data exists in a non-contact CPU card through a non-contact read-write CPU card host and a computer reader-writer on the non-contact CPU card, if so, reading a data record in the non-contact CPU card, and emptying the card; and secondly, writing a copying data authority identifier into the non-contact CPU card through a non-contact reading and writing CPU card host and a non-contact CPU card upper computer reader-writer, wherein the identifier indicates that the non-contact CPU card has the authority of copying data.
Siemens PLC-CPU clock and statistics record system circuit board clock, both need form common time data (year, month, day, hour, minute, second), and its solution is: in order to solve the problem that after the clock on any circuit board runs for a long time (such as one day, one week and the like), time difference exists between the clock and a standard clock reference (such as Beijing time), the two clocks are certainly slightly different because the Siemens PLC-CPU and the statistical recording system are respectively provided with the clock on the circuit board. The common time data (year, month, day, hour, minute, second) of the two are formed by the following method: every other time (such as 60 seconds), the statistical recording system circuit board reads PLC-CPU clock data from Siemens PLC-CPU to a random access memory RAM in the statistical recording system circuit board by adopting MPI protocol through a first serial port connecting line and a DB9 serial interface; and the statistical recording system circuit board judges and compares the onboard clock data in the statistical recording system circuit board with the PLC-CPU clock data. Two cases can be distinguished.
In the first case, if the difference between the two clock data is less than a small value (e.g. 5 seconds), the middle value (called as the median time data) between the board-mounted clock data and the PLC-CPU clock data is taken; the statistical recording system circuit board executes a clock setting instruction of the statistical recording system circuit board, and the 'median time data' is set as a clock value of the internal statistical recording system circuit board; meanwhile, the circuit board of the statistical recording system sends the 'median time data' to the Siemens PLC-CPU by the MPI protocol through the first serial port connecting line and the DB9 serial interface, and the Siemens PLC-CPU completes the internal clock value setting according to the instruction.
In the second case, if the difference between the two clock data is greater than the small value (for example, 5 seconds), the larger value (called as large-value time data) in the board-mounted clock data and the PLC-CPU clock data is taken; the statistical recording system circuit board executes a clock setting instruction of the statistical recording system circuit board, and the large-value time data is set as a clock value of the internal statistical recording system circuit board; meanwhile, the circuit board of the statistical recording system sends the large-value time data to the Siemens PLC-CPU through the first serial port connecting line and the DB9 serial interface by adopting an MPI protocol, and the Siemens PLC-CPU completes the internal clock value setting according to the instruction.
The perception type for the Siemens PLC to its control object is six types of signals: the first type is a switching value Input node (e.g., I0.0), the second type is a switching value Output node (e.g., Q0.0), the third type is an Analog Input node (e.g., AIW0), and the fourth type is an Analog Output node (e.g., AQW 0). In particular signals of the fifth and sixth type: external variables (e.g., rotational speed monitoring signals of an external frequency converter) read through a communication interface (e.g., DB9, ethernet, etc.), referred to herein as signals of a fifth type; external variables (e.g., rotational speed commands for the inverter, etc.) sent to other devices via a communication interface (e.g., DB9, ethernet, etc.), referred to herein as signals of the sixth type.
In the first category, a control system for a switch-type operation feedback signal of a controlled object has been introduced into a switching value IO contact of a siemens PLC, and a scheme for acquiring statistical records is as follows: the statistical recording system circuit board is used for reading a signal (generally, 0 represents that a controlled device is not in an operating state, and 1 represents that the controlled device is in an operating state) of 0 or 1 of a point (such as I0.0) where an operating signal is accessed from a Siemens PLC-CPU to a certain storage space of a random access memory RAM by using an MPI protocol through a first serial port connecting line and a DB9 serial interface at fixed time intervals (such as 1 second, 1 minute or other numerical values).
In the first case: if the value of the read-back is the same as the last read state (as if it is 1), the running time length of the storage space inside the Flash memory is accumulated once for a fixed time interval (e.g. 1 second, or 1 minute, or other value) and written into the Flash memory.
In the second case: if the read value of the memory is the same as the last read state (e.g. 0), the running time length of the memory space in the memory is not accumulated for the fixed time interval (e.g. 1 second, 1 minute or other values) and is not written into the Flash memory.
In the third case: if the read value is different from the last read state (last time is 1, this time is 0), the running time length of the storage space in the storage space is not accumulated for the fixed time interval (such as 1 second, 1 minute or other values) and is not written into the Flash storage.
In a fourth case: if the read value is different from the last read state (0 last time, 1 time), the running time length of the storage space in the memory is not accumulated for the fixed time interval (such as 1 second, 1 minute or other values) and is not written into the Flash memory.
In the second category, a control system of a switch type operation control signal of a controlled object is introduced into a switching value IO contact of the Siemens PLC, and the scheme of collecting statistical records is as follows: the statistical recording system circuit board is used for reading a signal (generally, 0 represents that a controlled device is not in an operating state, and 1 represents that the controlled device is in an operating state) of 0 or 1 of a control point (such as Q0.0) of an operating signal from a Siemens PLC-CPU to a certain storage space of a random access memory RAM by using an MPI protocol through a first serial port connecting line and a DB9 serial interface at fixed time intervals (such as 1 second, 1 minute or other values).
In the first case: if the value of the read-back is the same as the last read state (like 1), the running time length of the storage space inside the device is accumulated for a fixed time interval (such as 1 second, or 1 minute, or other values), and written into the Flash storage.
In the second case: if the read value of the memory is the same as the last read state (e.g. 0), the running time length of the memory space in the memory is not accumulated for the fixed time interval (e.g. 1 second, 1 minute or other values) and is not written into the Flash memory.
In the third case: if the read value is different from the last read state (last time is 1, this time is 0), the running time length of the storage space in the storage space is not accumulated for the fixed time interval (such as 1 second, 1 minute or other values) and is not written into the Flash storage.
In a fourth case: if the read value is different from the last read state (0 last time, 1 time), the running time length of the storage space in the memory is not accumulated for the fixed time interval (such as 1 second, 1 minute or other values) and is not written into the Flash memory.
In the third category, a control system for monitoring the analog quantity of the controlled object has been introduced into the analog quantity input contact of the siemens PLC, that is, the siemens PLC collects the analog quantity parameters (such as the operating current of the motor) of the controlled object, and the scheme of collecting the statistical records is as follows: the statistical recording system circuit board is used for reading a digital signal of an analog quantity point (such as AIW0) accessed by an operation signal from a Siemens PLC-CPU by using an MPI protocol through a first serial port connecting line and a DB9 serial interface according to the MPI protocol at a fixed time interval (such as 1 second, 1 minute or other numerical values), and after range conversion (such as 65535 corresponding to 100 amperes and 0 corresponding to 0 ampere), the digital signal is transferred to a certain storage space of a random access memory RAM. If the measured working current value of the controlled object after the range conversion is greater than a certain threshold value (such as 50 amperes), the load state of the controlled object is considered to be in a heavy load state, otherwise, the load state is judged to be in a light load state, and the following four conditions are processed by the method.
In the first case: if the load state of the controlled object is judged to be the same as the last time (as if the controlled object is a heavy load), the running time length of the storage space in the controlled object is accumulated once for a fixed time interval (such as 1 second, 1 minute or other values) and written into a Flash storage.
In the second case: if the load state of the controlled object is judged to be the same as the previous load state (like light load), the running time length of the storage space in the controlled object is not accumulated for the fixed time interval (such as 1 second, 1 minute or other values) at the time, and is not written into a Flash storage.
In the third case: if the load state of the controlled object is judged to be different from the previous time (for example, the previous time is light load, and the current time is heavy load), the running time length of the storage space in the controlled object is not accumulated for the fixed time interval (for example, 1 second, 1 minute or other numerical values) of the time, and is not written into a Flash storage.
In a fourth case: if the load state of the controlled object is judged to be different from the previous time (if the previous time is a heavy load, the current time is a light load), the running time length of the storage space in the controlled object is not accumulated for the fixed time interval (such as 1 second, 1 minute or other numerical values) of the time, and is not written into a Flash storage.
And in the fourth category, for an analog quantity output connection point of the Siemens PLC, the analog quantity output connection point is externally sent to a control system of a parameter input control channel of the controlled object, namely, the Siemens PLC is connected with the controlled object through the analog quantity output channel (for example, different analog quantities correspond to corresponding valve opening degrees), and the scheme for collecting statistical records is as follows: the statistical recording system circuit board is used for reading and outputting a digital signal of an analog quantity point position (such as AQW0) from a Siemens PLC-CPU by using an MPI protocol through a first serial port connecting line and a DB9 serial interface according to the MPI protocol at a fixed time interval (such as 1 second, 1 minute or other numerical values), and the digital signal is transferred to a certain storage space of a random access memory RAM after range conversion (such as 65535 corresponding to 100% valve opening degree and 0 corresponding to 0% valve opening degree). If the measured value of the controlled object after the range conversion is greater than a certain threshold value (for example, 50%), it is determined that the opening degree state of the controlled object is in the large opening degree state, otherwise, it is determined that the controlled object is in the small opening degree state, and the processing method is divided into the following four cases.
In the first case: if the opening state of the controlled object is judged to be the same as the previous opening state (like large opening), the running time length of the storage space in the controlled object is accumulated once for a fixed time interval (such as 1 second, 1 minute or other values) and written into a Flash storage.
In the second case: if the opening state of the controlled object is judged to be the same as the previous opening state (like small opening), the running time length of the storage space in the controlled object is not accumulated for the fixed time interval (such as 1 second, 1 minute or other values) at the time, and is not written into a Flash storage.
In the third case: if the opening state of the controlled object is judged to be different from the previous time (for example, the previous time is a small opening, and the current time is a large opening), the running time length of the storage space in the controlled object is not accumulated for a fixed time interval (for example, 1 second, 1 minute or other numerical values) of the current time, and is not written into a Flash storage.
In a fourth case: if the opening state of the controlled object is judged to be different from the previous opening state (such as the previous opening state is a large opening state, and the current opening state is a small opening state), the running time length of the storage space in the controlled object is not accumulated for a fixed time interval (such as 1 second, 1 minute or other numerical values) of the current time, and is not written into a Flash storage.
The fifth type, the processing method is the same as the third type through external feedback analog variables (such as the rotating speed acquisition feedback signals of an external frequency converter) read by a communication interface (such as DB9, Ethernet and the like); the processing method of the external feedback switch variables (such as the on/off state signals of the external frequency converter) read by the communication interface (such as DB9, Ethernet and the like) is the same as the first type.
The sixth type, the external analog type variables (such as rotating speed instruction of an external frequency converter, valve opening instruction and the like) sent to other equipment through a communication interface (such as DB9, Ethernet and the like) and the processing method is the same as the fourth type; the processing method of the external switch variables (such as on/off command signals of an external frequency converter) sent to other equipment through a communication interface (such as DB9, Ethernet and the like) is the same as the second type.
Particularly, for the third category and the sixth category which relate to the maximum numerical value of the analog quantity (such as the rotating speed instruction and the valve opening instruction of the external frequency converter, the rotating speed acquisition feedback signal of the external frequency converter, and the like), the scheme for acquiring the statistical record is as follows: the method comprises the steps of counting and recording a fixed time interval (such as 1 second/time, or 1 minute/time, or other numerical values) of a system circuit board, reading and outputting a numerical value signal of an analog quantity point (such as AQW0) or a certain intermediate variable from a Siemens PLC-CPU by adopting an MPI protocol through a first serial port connecting line and a DB9 serial interface according to the MPI protocol, and transferring the numerical value signal into a certain storage space of a Random Access Memory (RAM) after range conversion (such as 65535 corresponding to 100% of valve opening degree and 0 corresponding to 0% of valve opening degree). If the value is smaller than the value stored in the corresponding storage unit in the Flash storage, no processing is carried out; otherwise, updating the numerical value in the Flash memory and recording the clock of the moment in the Flash memory.
When the non-contact CPU card approaches to the non-contact CPU card reading and writing coil of the airborne non-contact CPU card reader-writer, the non-contact CPU card reading and writing coil senses that the non-contact CPU card approaches, and the airborne non-contact CPU card reader-writer sends a card approaching signal to the statistical recording system circuit board through the second serial port connecting line and the airborne non-contact CPU card reader-writer interface of the statistical recording system circuit board. And the circuit board of the statistical recording system issues a card reading command to the onboard non-contact CPU card reader-writer. And the onboard non-contact CPU card reader-writer reads the authority information of the copied data in the non-contact CPU card and sends the authority information to the statistical recording system circuit board through a second serial port connecting line and an onboard non-contact CPU card reader-writer interface of the statistical recording system circuit board. And the circuit board of the statistical recording system judges whether the non-contact CPU card has the permission to copy data. And after judging that the data in the non-contact CPU card has the authority of reading the data, writing key numbers such as the accumulated duration, the maximum current value, the maximum opening degree value and the like of various variables into the non-contact CPU card. And the non-contact CPU card with the data reading authority reads the accumulated numerical value in the circuit board of the statistical recording system.
And finally, reading the copied data in the non-contact CPU card and resetting the copied data into the non-contact CPU card with the copying authority, wherein the scheme is as follows: firstly, reading data in a non-contact CPU card from the non-contact CPU card through a non-contact CPU card host computer and a non-contact CPU card upper computer reader-writer, and writing an identifier into the non-contact CPU card, wherein the identifier indicates that the non-contact CPU card has the authority of reading the data.
In order to avoid the problems that the Siemens PLC-CPU and the statistical recording system circuit board are not started and are not powered off at the same time, the Siemens PLC-CPU and the statistical recording system circuit board are powered from the same power supply.
Likewise, six types of signals based on the above-described type of perception of the subject of control by the Siemens PLC. In the six types of signals, the change of the switching value or the analog value exceeding a certain threshold value is generally called a control system event. Based on the above thought, under the premise of not paying creative labor, other records of accumulated time or event occurrence time are obtained through different event processing methods.
Similarly, for the PLCs of other manufacturers, the same effect on the PLCs of other manufacturers can be achieved by adopting the programming ports (also called program downloading interfaces and downloading interfaces) through the connection mode provided by the invention and through the special protocol of the manufacturers.
The PLC operation data recording method based on the multi-master-station communication mode provided by the embodiment of the invention realizes the tamper-proof recording and transmission of key operation accumulated data even in places without network coverage; on the basis of not changing the original program of the PLC, the functions of inquiring, accumulating, counting and the like of internal data can be realized, and the internal data can be stored in a CPU type IC card which is copy-proof and tamper-proof.
Based on the foregoing embodiment, further, fig. 2 is a schematic diagram of a PLC operating data recording device based on a multi-master-station communication mode according to an embodiment of the present invention, and as shown in fig. 2, an embodiment of the present invention provides a PLC operating data recording device based on a multi-master-station communication mode, which includes a sending module 201 and a recording module 202, where:
the sending module 201 is configured to periodically receive device search data frames sent by a target PLC, and after responding, receive data frames fed back by the target PLC, where the data frames are used as channel state monitoring data frames; the channel state monitoring data frame is used for indicating the target PLC to feed back a channel state response data frame within a preset time; the recording module 202 is configured to determine that a data channel between the target PLC and the target PLC is in a disconnected state if the channel status response data frame is not received within the preset time; and if the channel state response data frame is received within the preset time, determining that the data channel between the target PLC and the target PLC is in a connection state, and reading and recording operation data from the target PLC according to a multi-master-station communication mode.
The PLC operation data recording device based on the multi-master-station communication mode provided by the embodiment of the invention realizes the tamper-proof recording and transmission of key operation accumulated data even in places without network coverage; on the basis of not changing the original program of the PLC, the functions of inquiring, accumulating, counting and the like of internal data can be realized, and the internal data can be stored in a CPU type IC card which is copy-proof and tamper-proof.
Fig. 3 is a schematic structural diagram of an electronic device according to an embodiment of the present invention, and as shown in fig. 3, the electronic device includes: a processor (processor)301, a communication Interface (communication Interface)302, a memory (memory)303 and a communication bus 304, wherein the processor 301, the communication Interface 302 and the memory 303 complete communication with each other through the communication bus 304. The processor 301 and the memory 302 communicate with each other via a bus 303. Processor 301 may call logic instructions in memory 303 to perform the following method:
periodically receiving equipment searching data frames sent by a target PLC, and receiving data frames fed back by the target PLC after responding, wherein the data frames are used as channel state monitoring data frames; the channel state monitoring data frame is used for indicating the target PLC to feed back a channel state response data frame within a preset time;
if the channel state response data frame is not received within the preset time, determining that a data channel between the target PLC and the target PLC is in a disconnected state; and if the channel state response data frame is received within the preset time, determining that the data channel between the target PLC and the target PLC is in a connection state, and reading and recording operation data from the target PLC according to a multi-master-station communication mode.
In addition, the logic instructions in the memory may be implemented in the form of software functional units and may be stored in a computer readable storage medium when sold or used as a stand-alone product. Based on such understanding, the technical solution of the present invention may be embodied in the form of a software product, which is stored in a storage medium and includes instructions for causing a computer device (which may be a personal computer, a server, or a network device) to execute all or part of the steps of the method according to the embodiments of the present invention. And the aforementioned storage medium includes: a U-disk, a removable hard disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), a magnetic disk or an optical disk, and other various media capable of storing program codes.
Further, embodiments of the present invention provide a computer program product comprising a computer program stored on a non-transitory computer-readable storage medium, the computer program comprising program instructions which, when executed by a computer, enable the computer to perform the steps of the above-described method embodiments, for example, including:
periodically receiving equipment searching data frames sent by a target PLC, and receiving data frames fed back by the target PLC after responding, wherein the data frames are used as channel state monitoring data frames; the channel state monitoring data frame is used for indicating the target PLC to feed back a channel state response data frame within a preset time;
if the channel state response data frame is not received within the preset time, determining that a data channel between the target PLC and the target PLC is in a disconnected state; and if the channel state response data frame is received within the preset time, determining that the data channel between the target PLC and the target PLC is in a connection state, and reading and recording operation data from the target PLC according to a multi-master-station communication mode.
Further, an embodiment of the present invention provides a non-transitory computer-readable storage medium, on which a computer program is stored, and when the computer program is executed by a processor, the computer program implements the steps in the above method embodiments, for example, including:
periodically receiving equipment searching data frames sent by a target PLC, and receiving data frames fed back by the target PLC after responding, wherein the data frames are used as channel state monitoring data frames; the channel state monitoring data frame is used for indicating the target PLC to feed back a channel state response data frame within a preset time;
if the channel state response data frame is not received within the preset time, determining that a data channel between the target PLC and the target PLC is in a disconnected state; and if the channel state response data frame is received within the preset time, determining that the data channel between the target PLC and the target PLC is in a connection state, and reading and recording operation data from the target PLC according to a multi-master-station communication mode.
The above-described embodiments of the apparatus are merely illustrative, and the units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of the present embodiment. One of ordinary skill in the art can understand and implement it without inventive effort.
Through the above description of the embodiments, those skilled in the art will clearly understand that each embodiment can be implemented by software plus a necessary general hardware platform, and certainly can also be implemented by hardware. With this understanding in mind, the above-described technical solutions may be embodied in the form of a software product, which can be stored in a computer-readable storage medium such as ROM/RAM, magnetic disk, optical disk, etc., and includes instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to execute the methods described in the embodiments or some parts of the embodiments.
Finally, it should be noted that: the above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.
Claims (9)
1. A PLC operation data recording method based on a multi-master-station communication mode is characterized by comprising the following steps:
periodically receiving equipment searching data frames sent by a target PLC, and receiving data frames fed back by the target PLC after responding, wherein the data frames are used as channel state monitoring data frames; the channel state monitoring data frame is used for indicating the target PLC to feed back a channel state response data frame within a preset time;
if the channel state response data frame is not received within the preset time, determining that a data channel between the target PLC and the target PLC is in a disconnected state; and if the channel state response data frame is received within the preset time, determining that the data channel between the target PLC and the target PLC is in a connection state, and reading and recording operation data from the target PLC according to a multi-master-station communication mode.
2. The method as claimed in claim 1, wherein after determining that the data channel with the target PLC is in an off state, the method further comprises:
if the last period also monitors that the data channel between the PLC and the target PLC is in a disconnection state, accumulating the disconnection time between the PLC and the target PLC for one period;
and if the data channel between the PLC and the target PLC is in a connection state during the last period, not accumulating the disconnection time between the PLC and the target PLC.
3. The method as claimed in claim 1, wherein after determining that the data channel with the target PLC is in a connected state, the method further comprises:
if the last period also monitors that the data channel between the PLC and the target PLC is in a connection state, accumulating the connection time between the PLC and the target PLC for one period;
and if the data channel between the PLC and the target PLC is in a disconnected state during the last period, not accumulating the connection time between the PLC and the target PLC.
4. The PLC operation data recording method according to claim 1, wherein after the operation data is read from the target PLC and recorded according to the multi-master communication mode, the method further comprises:
receiving data copying request information sent by a non-contact CPU card, wherein the data copying request information carries a copied data authority identifier;
and if the copy data authority identification passes the verification, writing the recorded running data into a non-contact CPU card.
5. The method as claimed in claim 1, wherein after determining that the data channel with the target PLC is in a connected state, the method further comprises:
reading clock data from the target PLC according to a multi-master station communication mode;
and carrying out clock synchronization with the target PLC.
6. The PLC operation data recording method based on multi-master station communication mode according to any one of claims 1 to 5, wherein the operation data includes at least one of switching value input point data, switching value output point data, analog value input point data, analog value output point data, external variables read through the communication interface, and external variables transmitted to other devices.
7. The utility model provides a PLC operation data recorder based on many main website communication mode which characterized in that includes:
the transmitting module is used for periodically receiving equipment searching data frames transmitted by the target PLC, responding, and receiving data frames fed back by the target PLC, wherein the data frames are used as channel state monitoring data frames; the channel state monitoring data frame is used for indicating the target PLC to feed back a channel state response data frame within a preset time;
the recording module is used for determining that a data channel between the target PLC and the recording module is in a disconnected state if the channel state response data frame is not received within the preset time; and if the channel state response data frame is received within the preset time, determining that the data channel between the target PLC and the target PLC is in a connection state, and reading and recording operation data from the target PLC according to a multi-master-station communication mode.
8. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the steps of the PLC operation data recording method based on multi-master station communication mode according to any one of claims 1 to 6.
9. A non-transitory computer readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the steps of the PLC operation data recording method based on multi-master station communication mode according to any one of claims 1 to 6.
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| CN113219898B (en) * | 2021-07-08 | 2021-09-21 | 宜科(天津)电子有限公司 | Communication system of upper computer and PLC |
| CN113985800A (en) * | 2021-09-30 | 2022-01-28 | 中国船舶重工集团公司第七一八研究所 | Control system of PLC system expansion IO sub-station based on Ethernet communication |
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