Profinet to RS485 connection of three multi-function power meters configuration case

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Profinet to RS485 connection of three multi-function power meters configuration case [Copy link]

This case is a configuration case of using a Profinet to RS485 gateway to connect three multi-function power meters.
Required equipment: a Siemens 1200PLC, a Profinet to RS485 free protocol gateway, and three multi-function power meters;

1. How to use: Open Siemens Portal configuration software and add PLC;

2. Import the Profinet to RS485 gateway GSD file;

3. Set the gateway IP and device name of the Profinet to RS485 gateway (in this case, the name is GW1 and the device IP is 192.168.20.5); Profinet to RS485 gateway;

4. Set the received data length (32 bytes in this example);

5. Download the configuration to PLC, turn on the power meter and set the station number and baud rate of the meter;

6. Set the 485 parameters of the device (output mode, baud rate, data bit, address, etc.) and set the IP address and device name of the Profinet to RS485 gateway (consistent with the PLC);

7. Profinet to RS485 gateway The gateway can be set to master-slave mode and production/consumer mode. The master-slave mode requires the slave station to respond before continuing to send instructions. The input and output of the production and consumer mode do not interfere with each other. The physical standard is changed to 485 interface mode. The gateway is divided into 3 485 ports that need to be set separately;

8. Set the 485 parameters of the Profinet to RS485 gateway, such as baud rate, data bit, checksum, stop bit, etc. (consistent with the connected device). Take the master-slave mode as an example, add nodes and exchange commands;

9. Add sending data;

10. According to the device manual, the slave device uses Modbus communication, so we can write the corresponding modbus message and send it;

11. According to the message example, if the data to be sent is 8 bytes, then you only need to configure the data length to 8. The memory mapping parameter 1500 corresponds to the PLC's Q address QB64. That is, QB64=0CH(1500), QB65=03H(1501), QB66=00H(1502)
QB67=0FH(1503), QB68=00H(1504), QB69=06H(1505), QB70=F5H(1506), QB71=CBH(1507);

12. In addition to the numerical value sent by PLC, the gateway can also send a fixed numerical value, without PLC writing the value to convert the hexadecimal message into decimal. Select the decimal number 12 with the constant value of 0CH;

13. The second one is 03H, the decimal number 3, and so on;

14. The slave station adds the corresponding value (in this example, the slave station response has 17 bytes, so the write data length is 17. If it is a different length, you can choose a variable length);

15. Load the configuration to the Profinet to RS485 gateway and then power it on again. (If you modify the configuration again without changing the gateway IP and device name, you do not need to restart).

kingpower2008

The Profinet to RS485 gateway project seems to be very successful. It is widely used in power integrated meters, generally using the modbus protocol.