SunSaver MPPT MODBUS Document

General Information
The TriStar MPPT supports the industry standard MODBUS® application protocol via its serial RS-232 and
EIA-485 interfaces and MODBUS TCP via the Ethernet port (TS-MPPT-60 models only). This document
assumes the user is familiar with both MODBUS® protocols. Please refer to the documents listed in the
References section for more information.
MODBUS® is a registered trademark of Modbus-IDA (
www.modbus-ida.org
)
Parameters
The TriStar MPPT supports RTU mode only.
16bit MODBUS addresses (per the modbus.org spec)
The serial communication parameters:
 BPS 9600 baud
 Parity None
 Data bits 8
 Stop bits 1 or 2*
 Flow control None
*The TriStar accepts either 1 or 2 stop bits. It will send 2 stop bits to provide extra byte padding. The
connected PC can be set to receive either 1 or 2 stop bits.
The default TCP communication parameters:
DHCP enabled
Port 502
MODBUS ID 1
NETBIOS address tsmppt + serial number (no spaces)
LiveView Web address http://tsmpptXXXXXXX (where X is the serial number)
If DHCP fails, the following default parameters will be assigned:
IP 192.168.1.253
Gateway 192.168.1.1
Primary DNS 192.168.1.1
Secondary DNS 192.168.1.1
Subnet Mask 255.255.255.0
Note: the TCP socket is closed by the TS-MPPT after each MODBUS response (change pending)
All addresses listed are for the request PDU.