CN-121995839-A - Digital control system based on integrated board and design method of control system
Abstract
The invention relates to a digital control system based on an integrated board and a design method of the control system, wherein the system comprises a PLC board card, a frequency converter board card, a touch screen and a motor; the PLC board card and the frequency converter board card are fixedly arranged on the electric board, the PLC board card is provided with a board card interface for connecting an external sensor and an instrument and meter, the PLC board card is used for collecting the external sensor and realizing constant-pressure water supply and some abnormal protection by regulating and controlling the start and stop and the rotating speed of each frequency converter to the motor in real time, all external signals are required to pass through the PLC board card, meanwhile, the PLC board card and the frequency converter board are communicated by adopting an RS485 bus, the working state of the frequency converter board is read, the start and stop and the debugging of the frequency converter board are controlled, the motor is further controlled, the touch screen is connected with the PLC board card by the bus, and the touch screen and the control power supply are provided by the PLC board card. The invention has the advantages of low cost, space saving, high wiring efficiency, convenient maintenance and strong environment adaptation capability.
Inventors
- LIN XIAOLIAN
- DONG XUEFENG
- YU LEI
Assignees
- 上海凯泉泵业（集团）有限公司
Dates
- Publication Date
- 20260508
- Application Date
- 20260410
Claims (8)
- 1. The integrated board-based digital control system is characterized by comprising a PLC board card, a frequency converter board card, a touch screen and a motor, wherein the PLC board card and the frequency converter board card are fixedly arranged on an electric board; the PLC board is provided with a board interface for connecting an external sensor and an instrument and meter, and the frequency converter board is used for receiving a control command of the PLC and feeding back the running state of the motor; the PLC board card is used for collecting external sensors, and realizing constant-pressure water supply and abnormal protection by regulating and controlling the start and stop of each frequency converter on a motor and controlling the rotating speed in real time; The PLC board card is the core of the whole control system, all external signals need to pass through the PLC board card, meanwhile, the PLC board card and the frequency converter board block are communicated by adopting an RS485 bus, the working state of the frequency converter board block is read, the start, stop and debug of the frequency converter board card are controlled, and then the motor is controlled; The touch screen is connected with the PLC plate through a bus, and the touch screen and the control power supply are provided by the PLC plate card.
- 2. The digital control system based on the integrated board of claim 1, wherein the PLC board card and the touch screen adopt an Ethernet TCP communication mode, and the PLC board card and the plurality of frequency converters adopt a Modbus RTU protocol based on an RS485 bus interface to realize the state reading, the control and the parameter modification of the frequency converters.
- 3. The digital control system based on integrated board of claim 1, wherein the electric board is installed inside the frequency converter cabinet, the frequency converter shell is installed through the wall, and the radiating aluminum board and the fan are arranged outside the cabinet.
- 4. The digital control system based on an integrated board of claim 1, wherein the PLC on the PLC board card is provided with at least 3 groups of expansion RJ45 ports with 1-path RS485 communication ports for communicating with the frequency converter.
- 5. The digital control system based on the integrated board of claim 1, wherein a transparent acrylic plate which is convenient to observe and protect is arranged outside after the PLC board card and the frequency converter board card are combined.
- 6. The digital control system based on the integrated board of claim 1, wherein the electronic board is sprayed with the three-proofing coating.
- 7. The digital control system based on integrated board of claim 1, wherein the PLC adds 5 NTC temperature measuring channels.
- 8. A design method based on an integrated board digital control system as set forth in one of claims 1-7, characterized in that the design method comprises the following steps: The design of a frequency converter integrated board, namely, an independent I/O board and a manual operator of a traditional frequency converter are canceled, only a bus interface for data interaction is reserved, and the frequency converter integrated board is used for receiving a PLC instruction to control the start, stop and speed regulation of a motor and feeding back the running state and data of the motor; integrating all I/O functions required by a control system into the PLC integrated board, wherein the I/O functions comprise external sensor signal acquisition, instrument and meter connection, abnormal protection signal processing and execution component control signal output, and the PLC integrated board does not need to be additionally provided with an expansion I/O module; Step 3, constructing a communication framework, namely establishing communication connection between the PLC integrated board and the frequency converter integrated board through a data bus to realize control instruction transmission, running state feedback and parameter data interaction; The integrated hardware installation comprises the steps that a PLC integrated board and a frequency converter integrated board are fixedly installed on an electric board by adopting bare board structures without shells, and three-proofing coatings are laid on the surfaces of the electric board and the integrated board; And 5, man-machine interaction configuration, namely, communicating with a PLC integrated board through a touch screen, realizing parameter setting and running state display of a control system and a frequency converter, and needing no additional configuration of an operation panel of the frequency converter.
Description
Digital control system based on integrated board and design method of control system Technical Field The invention relates to a control system and a design method of the control system, in particular to an integrated board-based digital control system with low cost, small space, convenient maintenance and high wiring efficiency and a design method of the control system. Background The current mainstream variable-frequency water supply control system still adopts a mode of combining a PLC controller with a plastic or metal shell and a frequency converter on hardware, the PLC controls the frequency converter through hard wiring, the switching value controls the frequency converter to start and stop, the analog value controls the frequency modulation scheme of the frequency converter to realize closed-loop constant-pressure water supply regulation, and the parameters of the frequency converter are checked and set through a frequency converter panel. In the prior art, the PLC and the frequency converter are integrated with an external shell body, generally the protection grade of IP21, and meanwhile, the cost of the shell is high, the heat dissipation performance is poor and the installation space is large. The cost problem is that the PLC and the frequency converter in the prior art are provided with metal or plastic shells, the PLC needs to expand the IO module, and the frequency converter needs to be provided with the IO board card, so that the hardware cost is increased. Space utilization, in order to effectively improve the space utilization, the size and space of the main components need to be reduced. The wiring convenience is that the control circuits of the PLC and the frequency converter are more easy to be connected in error and time-consuming in the prior art. And the maintenance convenience is that in the prior art, if the PLC or the frequency converter circuit board burns out or fails, the maintenance cannot be finished only by naked eye observation, and the comprehensive judgment of the shell needs to be dismantled. The environment-friendly circuit board is suitable for the environment, and the circuit board is easy to be damaged due to damp caused by dark and moist environment because the water supply pump house is generally arranged in a basement, and the circuit board in the prior art has no protective coating. Disclosure of Invention Aiming at the problems, the invention mainly aims to provide an integrated board-based digital control system and a design method thereof, wherein the integrated board-based digital control system has the advantages of low cost, small space, convenient maintenance and high wiring efficiency. The integrated board-based digital control system comprises a PLC board card, a frequency converter board card, a touch screen and a motor, wherein the PLC board card and the frequency converter board card are fixedly arranged on an electric board. The PLC board is provided with a board interface for connecting an external sensor and an instrument, and the frequency converter board is used for receiving a control command of the PLC and feeding back the running state of the motor by adopting an RS485 communication mode with the PLC. The PLC board card is used for collecting external sensors, and realizing constant-pressure water supply and abnormal protection by regulating and controlling the start and stop of each frequency converter on a motor and controlling the rotating speed in real time. The PLC board card is the core of the whole control system, all external signals need to pass through the PLC board card, meanwhile, the PLC board card and the frequency converter board block are communicated by an RS485 bus, the working state of the frequency converter board block is read, the start, stop and debugging of the frequency converter board card are controlled, and then the motor is controlled. The touch screen is connected with the PLC plate through a bus, the touch screen and a control power supply are provided by a PLC plate card, and an external sensor and an instrument are connected to the plate card interface. In the specific embodiment of the invention, the PLC board card and the touch screen adopt an Ethernet TCP communication mode, and the PLC board card and the plurality of frequency converters adopt a Modbus RTU protocol based on an RS485 bus interface to realize the state reading, the control and the parameter modification of the frequency converters. In the specific embodiment of the invention, the electric plate is arranged on the inner side of the frequency converter cabinet, the frequency converter shell is arranged through the wall, and the radiating aluminum plate and the fan are arranged outside the cabinet. In the specific embodiment of the invention, at least 3 groups of expansion RJ45 ports of 1-path RS485 communication ports are added on a PLC (programmable logic controller) board card for communicating with a frequency converter. In the specific embodi