Connecting to a SunSpec Device

It is often helpful to quickly visualize, read, and write SunSpec Modbus holding registers. This functionality allows:

  • Software developers a quick way to evaluate the SunSpec implementation
  • Power electronics engineers the ability to configure the equipment
  • DER operators write access to the Modbus server and device measurement feedback
  • Testing laboratories can quickly check on the state of the equipment and make appropriate modifications the device

Connection Types

There are three types of SunSpec-compliant equipment that can be accessed with LabTest Plus:

  • Modbus RTU - A Modbus device connected to the computer using a serial connection.
  • Modbus TCP - A Modbus device connected to the computer via a local area network.
  • Modbus File - A virtual or cloned device represented by a json file.

Connecting to a Device

To connect to the equipment, click Device → Open and select the type of device that you would like to connect to from the menu, and enter the following information:

  • Modbus TCP
    • IP Address - Device IP address
    • IP Port - The IP port for the Modbus server, typically 502
    • Unit ID - The Modbus ID
    • Timeout (secs) - Connection timeout in seconds
  • Modbus RTU
    • Interface Name - Windows serial communication port, e.g., COM0
    • Unit ID - The Modbus ID
    • Baud Rate - Serial communication port baud rate. Options include 9600, 19200, 115200, etc.
    • Parity - Serial communication port parity
    • Timeout (secs) - Connection timeout in seconds
  • Device File
    • File Name - Path to the device information model json file. These files can be generated using the Device → Export As functionality included in LabTest Plus.

Interacting with a Device

Once a device is connected, it is possible to:

  • Inspect the supported SunSpec models and supported SunSpec points.
  • Read the SunSpec models or poll the registers at a set interval.
  • Write Modbus registers to change the operation of the equipment.