Abstract: The requirements for remote control and networking in engineering projects are increasing and increasing. Fieldbus is increasingly prevalent as a reliable solution for the site, and CANopen is becoming more and more widely used as one of the field buses. Based on a detailed analysis of Hilscher's netTAP gateway products, this article describes how to realize the network communication between Hilscher CANopen gateway and Schneider Twido series PLC.
Keywords: Fieldbus CANopen Schneider Twido PLC Gateway
Abstract: The requirement for remote control and network control in projects become more and more, fieldbus as one reliable solution is so popular, and as one fieldbus CANopen protocol, application is more and more widely, so this article is deeply researching on the CANopen communication Between Hilscher netTAP gateway and Schneider Twido PLC. Hoping it can benefit for engineers.
Key words: FieldBus CANopen Twido PLC Gateway
1 Introduction
The rapid development of industrial automation, the perfect combination of networked concepts and automation has made remote control and engineering networking easier. Fieldbus as a network bus has its advantages in engineering, real-time performance, reliability enhancement, and on-site Wiring is simpler, and more and more projects use fieldbus for remote monitoring and networking. Today's fieldbus technology has grown tremendously, and the number of fieldbus protocols is also very large. CANopen, as a member of the fieldbus family, has received the support of numerous automation vendors with its own advantages. As an expert in the field of industrial communications, Hilscher Germany products cover all major fieldbuses and real-time Ethernet. For the CANopen bus protocol, Hilscher products are also very rich, including NT30-COS-RS, which is widely used in engineering. Can realize the direct interconnection of the serial port equipment and CANopen equipment, after analyzing the technical characteristic of NT30-COS-RS in detail in this article, explain in detail how to realize the communication with Schneider Twido series PLC.
2Features of the German Hilscher NT30-COS-RS
Hilscher's netTAP gateway family enables protocol conversion between serial (RS232/RS422/RS485) and fieldbus (CANopen, Profibus, DeviceNet, etc.) or Ethernet (TCP/IP, Ethernet/IP, ModbusTCP, etc.) The Hilscher configuration software SyCon.net can be used simply for configuration. NT30-COS-RS is one of the members of netTAP. The function is to interconnect the Modbus RTU serial device and the CANopen device. The input and output process image area is used for data exchange. The serial port can be configured as Modbus master or slave by software. The application is very convenient. The size of the process image area in the NT30-COS-RS is 256 Words IO, which means that the serial port can simultaneously receive 256 Words IO data transmissions, which are sent to the CANopen master device through the shared memory pass-through method, so multiple Modbus RTU serial ports Only one NT30-COS-RS is required for the device. The hardware diagram is shown in Figure 1.
Figure 1. The netTAP hardware diagram
3 Composition of Communication System
The system hardware structure diagram is shown in Figure 2. Schneider CANopen master module TWDNCO1M is used as CANopen bus master node, Node ID is set to 1, and Hilscher NT30-COS-RS gateway is used as a slave node in the CANopen bus. Node ID Set to 3, Schneider Twido series PLC model is TWDLMDA20DRT, Modbus RTU serial device brand is not limited.
Figure 2. CANopen communication hardware structure
4 Communication System Implementation
The realization of the interconnection of different manufacturers' equipments is the greatest advantage of the communication system's reference to the concept of networking and the standardization of products. This also makes the engineering application more flexible and the options available for the solution are larger. The prerequisites for the interconnection of different manufacturers' equipments are: The products produced by each manufacturer must strictly follow the standards and provide a unified product description file, such as CANopen's EDS file, Profibus' GSD file, etc. Through these product description files, the configuration and parameter configuration of the network can be realized, which is also a crucial step for realizing the communication function in the networking project.
4.1 Hardware Configuration
Under normal circumstances, each manufacturer will provide a network configuration tool for its own CANopen master station (in the future, if each vendor's equipment is based on FDT/DTM technology, which can realize the interchange of network tools), such as Schneider's Twidosoft, internal integration of Twido series PLC The hardware configuration module. The following uses Twidosoft version 3.5 as an example. It uses Schneider's USB hardware configuration cable to describe in detail how to implement the network configuration of Schneider's CANopen master station and the German Hilscher CANopen slave station NT30-COS-RS. This is also a precondition for implementing communication functions and writing control programs.
After installing the Twidosoft 3.5 software and USB driver, open Twidosoft and select the USB connection method in file-preferences, create a new project, select the PLC model (this article uses the TWDLMDA20DRT model), and right-click on the expansion bus in the hardware configuration. Module, add TWDNCO1M module (Schneider CANopen module), can add multiple modules at the same time, right enter the configuration interface, load and parameter configuration of network slave information. As shown in Figure 3.
Figure 3. CANopen Configuration Screen
Add the Slave EDS file via the Import button. The EDS of the German Hilscher NT30-COS-RS is called "Nt30cos.eds" and can be obtained through various methods, such as the Hilscher website, the netTAP CD or the Hilscher Shanghai. After the EDS information is loaded, the NT30-COS-RS is selected and the basic information of the product is displayed in the lower left corner. In this case, you can double-click to add slaves. You can add multiple slaves. According to Schneider CANopen master module information, up to 16 accept PDOs and 16 transmit PDOs. If the number of PDOs of each slave device is different, connect. The number of slaves will also change. Slave address can be based on the actual address of the slave. Select the address by using the up and down keys. The slave address of the NT30-COS-RS from Hilscher is set via the DIP switch (usually there are two ways to set the slave address). Kind: one set by hardware, one set by software, set slave address to 3. In addition, it is necessary to set the way the master station monitors the status of the slave station. The optional methods include protection time, heartbeat or no setting. In this example, the protection time is selected.
In the CANopen network setting, in addition to setting the slave address to distinguish each slave node, there is also a crucial parameter setting, which is the setting of the baud rate. The CANopen master and slave exchange data. Before, check the baud rate information. If the baud rate is different, the communication connection cannot be performed and the baud rate must be exactly the same. There are many options for baud rate. In this example, 250kbs baud rate is selected. The baud rate of the master station is set at the bottom right of Figure 3, and the NT30-COS-RS slave station is set by Hysoft SyCon.net software.
After the loading of the CANopen slave is completed, and the key communication parameters of the slave address and baud rate are set, the PDO and SDO data of the CANopen slave must be mapped and connected. That is, the Mapping and Link content shown in Figure 3, in addition, in order to facilitate PLC programming, through the parameter instead of the actual parameter, so that the program has a better readability, you can PDO parameter name in the Symbol option.
4.2 Software Implementation
Hilsune's netTAP gateway is extremely flexible. Different firmwares can be downloaded through Hilscher's SyCon.net software to implement different protocol conversions. At the same time, the NT30-COS-RS can configure the serial port as a Modbus RTU master or slave through software, and set various parameters and IO information of the connected serial port device. The following describes the NT30-COS-RS parameter configuration process in detail. The NT30-COS-RS configuration tool is SyCon.net, which can be downloaded for free on the Hilscher Internet, delivered on CD-ROM, or contacted by Hilscher Shanghai Office.
Figure 4. SyCon.net user interface
As shown in Figure 4, after the new project, select the netTAP model you are using, in this case NT30-COS-RSI4. Drag the left button to the left green line and double-click to configure the parameters.
Figure 5. NT30-COS-RS parameter configuration interface
As shown in Figure 5, you first need to load firmware firmware under the Device option and select a different drive method to connect to the NT30-COS-RS in the Device Assignment. After the connection is established, the required firmware can be downloaded, and then the parameters are configured. The MODBUS directory is the basic configuration of the serial port information. The most important option is the Modbus master/slave option. The BUS_COS directory is the setting of the CANopen baud rate and must be the same as above. Schneider CANopen master baud rate settings are the same, the same choice 250kbs. If Modbus is selected as the master station, the parameters in the COMMAND directory are very important. Here you can set the IO data information of the connected Modbus slaves, the connected slave station address information, etc., and can support up to 256 Words IO data settings. See the reference [5] for details. In this case, NT30-COS-RS is used as a Modbus slave on the serial port. Therefore, you do not need to modify too many parameters, and you can directly download the device by right-clicking.
4.3 Software Testing
The following simple test tests whether the CANopen master station establishes a connection with the NT30-COS-RS slave. According to the Schneider CANopen module reference manual [1], specific system bits %SW20-%SW27 in the Twido series PLC can detect the communication connection status of the CANopen slave connected to the CANopen expansion module. The value of this status bit can be used to check whether the communication with the NT30-COS-RS CANopen slave is successful. Since the address of the slave station NT30-COS-RS connected in this example is 3, the data of %SW21 can be read.
Figure 6. Twidosoft Ladder Program
In the Twidosoft PLC program written by the ladder diagram programming language shown in Figure 6, read% SW20 and% SW21 system bit detection slave communication status. After writing a program in the ladder diagram programming language, connect the PLC, download the program, and enter the running state. By running the animation button, you can obtain the values ​​of the %SW20 and %SW21 system bits as 0 and 2, respectively. Compare the Schneider Software Operation Manual [1] In the system bit analysis, it can be seen that the slaves 1 and 2 have no connection module, and the slave 3 is connected to the slave without error and the operation status is good. It also shows that the Schneider CANopen master module successfully communicates with the Hilscher netTAP series NT30-COS-RS CANopen slave module.
5 Summary
This article uses the NT30-COS-RS CANopen slave and serial port protocol conversion modules in the Hayfinet netTAP gateway series, and the Schneider Twido series PLC plus the CANopen master module. The Twidosoft software is used to configure the parameters of the network communication using the Hyersty SyCon. The .net software carries on the parameter configuration to the NT30-COS-RS gateway, and writes the test procedure of Twido PLC through the ladder diagram programming language, tests the communication condition, the test result shows the communication condition is good. Hilscher's NT30-COS-RS CANopen slave module communicates with the Schneider CANopen master module. Hope to help the engineering networking project. At the same time, Hite Networks netTAP gateway series is also very rich. It hopes to bring convenience to engineering application personnel and solve the problems of remote monitoring and networking in engineering.
references
[1] Twidosoft Software Reference Manual V3.2_EN. Schneider, 2005.
[2] Twido Hardware Reference Manual V3.2_EN. Schneider, 2005.
[3] USB Port Programming Cable User Manual_CN. Schneider, 2005.
[4] ComProDTM_en. Hilscher Company. (Hilscher Automation Systems GmbH, Germany), 2004.
[5] NtCosMbr_en. Hilscher Company. (Hilscher Automation Systems GmbH, Germany), 2004.
About the Author
Zou Yuxuan (1980--) Male Master The technical support supervisor of Germany Hirsch Automation Systems Co., Ltd. specializes in network research in the industrial automation industry.