How can I communicate Magelis HMI to read data from an energy meter on Modbus using RS-485.
If want to read data from an Energy Meter that means you need to configure that energy meter as modbus slave and HMI as modbus master.
Kindly follow the below steps to achieve this configuration :
In HMI application make sure that in IOManager you have selected the Modbus RTU driver not the Modbus Slave RTU. Modbus Slave RTU will be selected in such case when you wanted to set the HMI as Modbus Slave.
In normal case when HMI is communicating with PLC it is configured as Modbus Master not the slave.
Apart from above you need to configure the Modbus Equipment in HMI application according the setting made in PLC's Modbus Manager port such as put the Slave ID as PLC's Slave ID. Baudrate, Parity, Stop Bit should match exactly as per the setting in energy meter.