SunSaver MODBUS Specifications

Logged Data
The SS-MPPT stores approximately 32 days of data. This data is stored in a circular buffer where the oldest
data is over-written by the newest data. The log data must be requested and sorted into correct order before the
data will be useful.
 The logged data is mapped from 0x8000-0x81FF (1kB)
 The data consists of up to 32 blocks of data. (One block is generally one day w/ some exceptions)
 Each block is 32bytes (16 modbus variables)
 It is written in a circular buffer format. All blocks must be read and then put in linear order via the
hourmeter field. Ignore blocks w/ hourmeters of 0x000000 or 0xFFFFFF. The largest hourmeter block
is the most recent.
PDU
Addr
Logical
Addr
Variable name Variable description
0x8000-
800F
32769-
32795
logger[0]
… …
0x81F0-
81FF
33249 -
33280
logger[31]
Data is stored in big endian format.
struct {
Uint24 hourmeter;
Uint24 alarm_daily;
Uint16 Vb_min_daily;
Uint16 Vb_max_daily;
Uint16 Ahc_daily;
Uint16 Ahl_daily;
Uint16 array_fault_daily;
Uint16 load_fault_daily;
Uint16 Va_max_daily;
Uint16 time_ab_daily; v0.7 code and later
Uint16 time_eq_daily; v0.7 code and later
Uint16 time_fl_daily; v0.7 code and later
Uint16 reserved[6];
}
Byte
Offset
Variable name Bytes Variable description Units Scaling or
Range
0 hourmeter 3 h 0 to (2
24
-1)
3 alarm_daily 3 Alarm bitfield – daily -
6 Vb_min_daily 2 Vb minimum voltage – daily V n·100·2
-15
8 Vb_max_daily 2 Vb maximum voltage – daily V n·100·2
-15
10 Ahc_daily 2 Ah charge – daily Ah n·0.1
12 Ahl_daily 2 Ah load – daily Ah n·0.1
14 array_fault_daily 2 Array fault bitfield – daily -