How to read data from Solar Inverter or Meter on a Windows PC

In this blog, we are going to describe how to poll data from any Modbus device (slave) on the pc/laptop (master).

Modbus Slave= Device from which data is to be requested
Modbus Master= Device on which data is to be seen (Windows PC)

Step-1 Gather supplies

Things required to communicate with Inverter or any other modbus based device are as following:

1. Cable for connecting to the device. Modbus RTU (RS485)-USB to RS485 connector with 2 core wire. Link
2. Driver of the above cable which is generally supplied with wire in CD or can be searched online.
3. PC based Modbus Simulator Software. You can try Modscan at this link
   Using this tool, you can query the value of a register from your Modbus Slave.
4. Modbus register mapping (communication protocol)  of the slave device.

Connect the USB to Modbus cable with the Slave. (Example – Connect A pin to RS485A port on slave and B Pin to RS485B port on slave)

Set following communication settings in slave

Modbus ID/Address – 1
Baud Rate-9600
Protocol- Modbus RTU/RS485

Detailed screen by screen settings manual is available at this link

Install driver of the cable used for connecting PC/Laptop to Slave
(Driver CD is generally provided sold with the connector or available online)

If you have purchased the USB to RS485 cable from above link then use this driver. Link

Once driver is installed correctly identify the COM port on which the USB is connected.