CN103853121B - A kind of controlled data stream multi-point data acquisition apparatus and method based on PLC - Google Patents

Abstract

The present invention discloses a kind of that can be used for industrial occasions multipoint acquisition data and requires the controlled collecting method of data stream and device.Including an industrial computer, connect at least one PLC by switch, number for each PLC, and numbering is unique, as the mark distinguishing different PLC；Thread pool is opened up, for processing the data communication of different PLC for each PLC；Control the data flow between industrial computer and PLC；At least one PLC, every PLC identify numbering and the numbering of other PLC of oneself, and when communication, numbering is resolved to IP address inside PLC；Every PLC opens two different ports, one as data sending terminal mouth, one as data receiver port.Data flow of the present invention is controlled, has higher motility, can meet the occasion that data collection point distribution regularity is poor.

Description

A PLC-based controllable data flow multi-point data acquisition device and method

technical field

The invention discloses a data collection method and device which can be used for multi-point data collection in industrial occasions and requires controllable data flow.

Background technique

PLC is a commonly used device for data acquisition in the industrial field. PLC has the characteristics of programmable and good stability. PLC-based data acquisition devices or methods are also common. However, these methods or devices often have a fixed data flow direction, such as the main control host computer in the control room. In the absence of the host computer, it often flows to a high-importance PLC, and then the host computer or PLC processes data in a unified manner. . This traditional way of data flow is uncontrollable, lacks flexibility, and cannot adapt to the increasingly complex needs of data collection in new industrial occasions.

Contents of the invention

In view of the above-mentioned deficiencies in the prior art, the technical problem to be solved by the present invention is to provide a controllable data flow multi-point data acquisition device and method based on PLC with controllable data flow direction.

The technical solution adopted by the present invention to achieve the above object is: a PLC-based controllable data flow multi-point data acquisition device, including

An industrial computer, connected to at least one PLC through a switch, number each PLC, and the number is unique, as a sign to distinguish different PLCs; open up a thread pool for each PLC to handle data communication between different PLCs; Control the data flow between industrial computer and PLC;

At least one PLC, each PLC recognizes its own number and the numbers of other PLCs, and the number is resolved into an IP address inside the PLC during communication; each PLC opens two different ports, one as a data sending port and one as an IP address. Data receiving port.

There is no master-slave distinction between the PLCs.

The industrial computer displays the communication status of each PLC and whether there is a fault and the type of fault.

The industrial computer displays all PLC data values in real time.

A PLC-based controllable data flow multi-point data acquisition method, comprising the following steps:

Enter the data source PLC number, data start area address, offset and target PLC number in the industrial computer;

The industrial computer sends communication commands to the data source PLC and the target PLC according to the input information;

The target PLC reads the data from the data start area to the offset of the data source PLC through the read method of the tcp/ip protocol.

The industrial computer sends communication commands to the data source PLC and the target PLC according to the input information, specifically:

The industrial computer corresponds the PLC number that needs to read data with the IP address of the PLC;

The industrial computer transmits the serial number of the target PLC to the data source PLC through the method of Ethernet communication.

The target PLC reads the data from the data start area of the data source PLC to the offset by the read method of the tcp/ip protocol, specifically:

The data source PLC obtains the starting address area and offset of the data to be read by analyzing the data content of the Ethernet communication method;

The data within the specified data start address area to the offset of the industrial computer flows from the data source PLC to the target PLC;

The industrial computer and the target PLC try to establish a connection; if the connection is successful, the industrial computer sends a data flow control command to the target PLC, and if the connection is unsuccessful, retry the connection;

The target PLC reads the data from the data start area to the offset of the data source PLC through the read method of the tcp/ip protocol.

The present invention has the following advantages:

1. The data flow is controllable and has high flexibility, which can meet the occasions where the distribution of data collection points is poor;

2. The industrial computer can display the real-time data of all terminal equipment, which is convenient for the observer to grasp the data collection situation and data value of each point at any time;

3. It can collect Ethernet type data, serial port type data, etc., can connect various types of sensors, and can meet most data collection requirements.

Description of drawings

Fig. 1 is a schematic diagram of the device circuit of the present invention;

Figure 2 is a data flow control method.

detailed description

The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments.

As shown in Figure 1-2, a PLC-based controllable data flow multi-point data acquisition device of the present invention includes: an industrial computer and several PLCs, and the PLC is connected to a digital input module, an analog input module, and a counter module, pulse generator module, RS232 module, RS485 module. Number each PLC, and the number is unique, open up a thread pool for each PLC in the industrial computer to handle the data communication of different PLCs, and record these numbers in the industrial computer as a sign to distinguish different PLCs. Each PLC recognizes its own number and the numbers of other PLCs, and the number is resolved into an IP address inside the PLC during communication. Each PLC opens two different ports, one as a data sending port and one as a data receiving port. Each PLC has the same status, there is no master-slave distinction, so that data can be exchanged between different PLCs. As a communication status display and control device, the industrial computer can display the communication status of each PLC, whether there is a fault and the type of fault, etc., and can also control the data flow through the industrial computer. For example, when the PLC at point A needs to read the data at point B , it can be controlled by the industrial computer, so that the data of point A is transmitted to point B, and the industrial computer can also display the data values of all points in real time.

The DC regulated power supply is WYJ600 DC regulated power supply from Shanghai Wenhua Power Equipment Co., Ltd.

The industrial computer chooses Siemens SIMATIC IPC847C industrial computer. SIMATIC IPC847C is a solid and extremely expandable industrial PC with a 19-inch design (4HM). Its outstanding long-term availability and thus high investment protection ensure reliable operation in harsh industrial environments, for example with high dust concentrations, high temperatures and high shock loads.

The network cable adopts ordinary double-headed RJ45 network cable, and the length of the network cable is less than 100 meters.

Cisco Express500 switches are selected as network switches. Cisco Catalyst Express500 switches provide double-layer network management, can manage Fast Ethernet and Gigabit Ethernet, provide non-blocking wire-speed performance and a secure network optimized for data, wireless and IP communications platform. The Cisco Catalyst Express500 also offers multiple Power over Ethernet (PoE) options to help reduce the cost and complexity of IP communications and support new uses of Ethernet.

PLC selects WAGO field bus controller, which is suitable for data transmission rate of 10/100Mbits/s and complies with IEC61131-3 programming standard. The controller provides 512KB of program memory, 256KB of data memory, and 24KB of hold memory. 32-bit CPU with multi-tasking function and battery-backed real-time clock. The controller provides a variety of different application protocols for data acquisition and control (MODBUS, ETHERNET/IP) or for system management and diagnosis (HTTP, BootP, DHCP, DNS, SNTP, FTP, SNMP and SMTP). The PLC field bus controller needs to be connected with data function modules, including analog input modules, digital input modules, RS232 communication modules, and RS485 modules.

The specific connection is as follows:

The Siemens industrial computer IPC847C and the Cisco Express500 switch are connected through a double-headed RJ45 network cable, and the switch is connected to a remote PLC through a network cable. The PLC controller includes a controller 750-881, an analog input module 750-476, and a digital input module 750-400 , Counter module 750-638, pulse generator module 750-635, RS232 communication module 750-650, RS485 communication module 750-653, terminal module 750-600, the above modules are connected at one time. These modules are connected to various sensors to collect the required data. The digital input module 750-400 can detect the rising edge voltage of 24VDC, connect it to the temperature alarm, and the temperature alarm will send out an alarm when the temperature reaches the preset temperature; the analog input module 750-476 can collect the analog input signal, Connect the pressure gauge, the pressure gauge converts the pressure value into 0~10VDC voltage output; the counter module 750-638 is connected to the counter, the pulse generator module 750-635 is connected to the pulse generator, and the RS232 communication module 750-650 is connected to the RS232 type serial communication Equipment, RS485 communication module 750-653 is connected to RS485 communication equipment.

The control data flow is realized jointly by industrial computer and PLC. First, enter the PLC number, data start area address, offset, and target PLC number in the industrial computer. After inputting the write information, the industrial computer sends communication commands to the data source PLC and the target PLC according to the input information, and the target PLC reads the data from the starting area to the offset through the read method of the tcp/ip protocol to complete the data flow control. Data flow control can also periodically control the data of a certain PLC to be transmitted to another PLC periodically through the timer.

The data flow control method of the present invention: correspond the PLC number to the IP address in the industrial computer; specify the data source PLC number; specify the starting address and offset of the data that the data source PLC wants to read; specify the data flow to the target PLC; industrial control The computer and the target PLC try to establish a connection; if the connection is successful, the industrial computer sends a data flow control command to the target PLC, and if the connection is unsuccessful, retry the connection; the target PLC reads the data through the read method of the tcp/ip protocol; waits for the data again flow control commands.

Claims (7)

1. A PLC-based controllable data flow multi-point data acquisition device, characterized in that, comprising An industrial computer, connected to at least one PLC through a switch, number each PLC, and the number is unique, as a sign to distinguish different PLCs; open up a thread pool for each PLC to handle data communication between different PLCs; Control the data flow between different PLCs; At least two PLCs, each PLC recognizes its own number and the number of other PLCs, and the number is resolved into an IP address inside the PLC during communication; each PLC opens two different ports, one as a data sending port, and one as an IP address. Data receiving port. 2. A PLC-based controllable data stream multi-point data acquisition device according to claim 1, characterized in that there is no master-slave distinction between said PLCs. 3. A kind of PLC-based controllable data flow multi-point data acquisition device according to claim 1, characterized in that, said industrial computer displays the communication status of each PLC and whether there is a failure and the type of failure. 4. A kind of PLC-based controllable data stream multi-point data acquisition device according to claim 1, characterized in that, said industrial computer displays all PLC data values in real time. 5. a PLC-based controllable data flow multi-point data acquisition method, is characterized in that, comprises the following steps: Enter the data source PLC number, data start area address, offset and target PLC number in the industrial computer; The industrial computer sends communication commands to the data source PLC and the target PLC according to the input information; The target PLC reads the data from the data start area to the offset of the data source PLC through the read method of the tcp/ip protocol. 6. a kind of PLC-based controllable data flow multi-point data acquisition method according to claim 5, is characterized in that, described industrial computer sends communication command to data source PLC and target PLC according to the information of input, specifically: The industrial computer corresponds the PLC number that needs to read data with the IP address of the PLC; The industrial computer transmits the serial number of the target PLC to the data source PLC through the method of Ethernet communication. 7. a kind of PLC-based controllable data flow multi-point data acquisition method according to claim 5, is characterized in that, described target PLC reads the data starting area of data source PLC by the read method of tcp/ip agreement to the data within the offset, specifically: The data source PLC obtains the starting address area and offset of the data to be read by analyzing the data content of the Ethernet communication method; The data within the specified data start address area to the offset of the industrial computer flows from the data source PLC to the target PLC; The industrial computer and the target PLC try to establish a connection; if the connection is successful, the industrial computer sends a data flow control command to the target PLC, and if the connection is unsuccessful, retry the connection; The target PLC reads the data from the data start area to the offset of the data source PLC through the read method of the tcp/ip protocol.