1. Field application: Modbus485 to Profinet gateway is applied to the PLC control system of a steel rolling company. In this system, Siemens PLC (S7-1200) is used as the Profinet master station, the high-order high-precision temperature controller TTM509 is used as the Modbus slave station, which supports Modbus485 communication, and the transfer from Modbus485 to Profinet gateway BX-601-PN of Beixun Technology is used as the bridge between the two to realize PLC monitoring and data acquisition of the temperature controller;

2. System requirements: 10 sets of temperature controller systems are monitored by Siemens S7-1200 PLC. Among them, the communication baud rate required by each temperature controller system is different;

3. System realization: according to the user's on-site requirements, each Modbus to Profinet gateway is connected to three sets of temperature controller systems (the baud rate of each Modbus to Profinet gateway on the serial port side should be set to be consistent with the serial port baud rate of the connected temperature controller through the configuration software), and the Profinet end of the Modbus to Profinet gateway is connected to the Profinet bus network (Siemens S7-1200 PLC), The 485 port of the Modbus to Profinet gateway is connected with the 485 port of the temperature controller (wired according to the panel or instructions in the manual), and then the data collected by the temperature controller is mapped to the input and output mapping area of S7-1200 PLC through the Modbus to Profinet gateway, so as to realize the real-time monitoring of 10 sets of temperature controller systems on the site by one PLC. Among them, BX-601-PN is widely used, All devices with Modbus RTU/ASCII (RS485) interface can use this product to realize interconnection with profinet devices of field bus, and quickly realize Modbus RTU/ASCII to profinet; Simple application, free configuration software, simple operation, and connection and communication in a short time; Modbus side supports Modbus master/slave functions;

4. TTM509: high-order high-precision temperature controller, dual channel input can be used for cascade control, remote SP setting, and position proportion control. The sampling period is 0.05s, the accuracy is 0.1%, the 5-digit display supports Modbus (RS485) communication, the serial communication baud rate supports 19200, 9600, etc., the data bit is 8 bits, there is no parity check, and the stop bit is 1;

5. The system structure diagram is as follows:

Beixun Technology Modbus485 to Profinet gateway-5.png

6. PLC configuration: import the GSD file of Modbus to Profinet gateway into the PROFINET master station configuration software. The GSD file provided by Modbus to Profinet can correspond to the functions of Modbus master station and Modbus slave station respectively. import the GSD file in the hardware configuration of Step 7, drag the module of Modbus to Profinet gateway to the PROFINET bus, and then set the configuration. After compiling and downloading, the communication test can be carried out. As shown in the figure below, multiple Modbus to Profinet gateways are configured and connected on the Profinet bus (one Modbus to Profinet gateway is connected to a set of temperature controller system). First drag the Modbus to Profinet gateway to the network, and then drag the data block to the slot at the bottom left of the configuration software. Double click the gateway to set the basic parameters of the device, including the IP address and device name, as shown in the following figure:

Beixun Technology Modbus485 to Profinet Gateway-6.png

7. Open the attribute device page of the data block, configure the Module according to the actual project requirements, and just calculate the total input and output of the connected devices, as shown in the following figure:

Beixun Technology Modbus485 to Profinet gateway-7.png

8. After setting, download the configuration to the PLC gateway configuration: open the gateway configuration software to set Profinet and Modbus. Click the New icon to select PN2MRM3;

Beixun Technology Modbus485 to Profinet gateway-8.png

9. Set the IP address and device name of the Modbus to Profinet gateway, which should be consistent with the PLC configuration;

Beixun Technology Modbus485 to Profinet gateway-9-1.png

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10. Set 485 parameters of each circuit;

Beixun Technology Modbus485 to Profinet gateway-10.png

11. Right click to add station number and function code;

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