Communication Protocols; Modbus Protocol Support; Modbus Rtu; Modbus Tcp - Nuvation Energy NUV300-BC-12 Product Manual

8. Communication Protocols

8.1. Modbus Protocol Support

Nuvation Energy BMS implements the SunSpec battery models defined in the Modular Energy Storage
Architecture (MESA) as the top-level Modbus interface to the product. Specifically the BMS
implements the MESA Draft 3 Storage models (800 Series).
The specifications for these models are available for download at
technical-resources.

MESA Draft 3 is currently implemented on Nuvation Energy BMS.

8.1.1. Modbus RTU

This protocol is used in serial communications. The default configuration is as follows:
▪
Baud rate: 38400
▪
Parity: even
▪
Data bits: 8
▪
Stop bits: 1
The Modbus RTU slave address must be set through software configuration. The default slave address
value is 1.

A slave address of zero is used as a broadcast address and should not be used as the
Modbus RTU slave address.

8.1.2. Modbus TCP

This protocol is used for communications over TCP/IP networks. A single Modbus TCP connection is
supported over port 502 for read and write access. All register data is transmitted as big endian
(most significant byte first).

8.1.3. Implemented MESA Models

The MESA standards contain a number of 'models' that can be implemented by vendors to describe a
storage device at various levels of detail. The models implemented by Nuvation Energy BMS are
described in the sections below.
Detailed register maps for all Draft 3 models are found in the document MESA-Energy-Storage-
Information-Models_Draft_3.xlsx found at the Nuvation Energy technical resources located at
https://www.nuvationenergy.com/technical-resources.
Document ID: NE-PM-002
Nuvation Energy Low-Voltage BMS - Product Manual
https://www.nuvationenergy.com/
138 Rev 1.2, 2021-03-03
Curie Update 1