SunSaver MPPT MODBUS Document

TriStar MPPT MODBUS Document v10
http://www.morningstarcorp.com 22/26 05 Dec 2011
Emeter _id
[57371][0xE01A](). MeterBus ID
Address which uniquely identifies the controller on the Morningstar proprietary Meter Bus network.
Devices are daisy-chained on the Meter Bus network via the RJ-11 connections. Addresses are limited to
the range of 1-15
EIb_lim
[57374][0xE01D](A). Battery Current Limit
Set to a non-zero value to limit the maximum battery current. Set to zero to use the default 60 Amp
current limit.
EVa_ref_fixed_init
[57377][0xE020](V). Array Voltage fixed target - initialize
Write a voltage value to this register to fix the Array input voltage to a specific value. If this register is a
non-zero value, the MPPT function of the controller will be disabled (sweeping and tracking are
disabled) and the array input will be fixed to the specified voltage. On start-up, the value in this register
is copied to the volatile RAM register 0x005A, which allows for real-time control of Va.
EVa_ref_fixed_pct_init
[57378][0xE021](%). Array Voltage percent of Voc voltage target - initialize
Write a value to this register to fix the Array input voltage to a percent of the Array open circuit voltage.
If this register is a non-zero value, the MPPT function of the controller will be disabled (sweeping and
tracking are disabled) and the array target voltage will be fixed to the specified % of array Voc. The
controller will perform periodic Voc checks and move the array voltage if needed to maintain the correct
% target. On start-up, the value in this register is copied to the volatile RAM register 0x005B, which
allows for real-time control of Va.
Note: if the Va_ref_fixed_init (0xE021) register is non-zero, it will override this setting.