Why do dca and dcw return zero or implausible values?

Raw integer readings in SunSpec Model 714 must be multiplied by 10 raised to the power of the corresponding scale factor register (dca_sf or dcw_sf). These scale factors are signed int16 values and can be negative, meaning the decimal point shifts left. Always apply the scale factor before interpreting a measurement.

The gateway connects but no registers respond. What is wrong?

SunSpec Model 714 is located at a dynamic base address, not a fixed one. The correct starting address depends on which models precede it in the device's Modbus map. Use SunSpec model discovery starting at address 40001 (or the device-specific SunSpec base) to walk the model chain and find Model 714's actual offset.

Why does prtalrms always read zero even during a known fault?

The prtalrms register is a uint32 bitmask where each bit corresponds to one DC port. If nprt reads less than the number of physically connected ports, the device firmware may not be populating all alarm bits. Check that the device firmware is current and that nprt reflects the correct port count for your installation.

Energy totals in dcwhinj and dcwhabs seem incorrect after a device reboot.

SunSpec cumulative energy registers are uint64 and may reset to zero on a device power cycle depending on firmware behavior. Cross-check the ModbusCloud historical data against the reset event timestamp to identify discontinuities, and use portal delta calculations rather than raw totals for energy reporting across reboots.

Free Modbus template: SunSpec Model 714 — DER DC Measurement

Name: SunSpec Model 714 — DER DC Measurement
Brand: SunSpec
SKU: 625a5b08-b685-41ff-9ba0-e79661693b28

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Free Modbus template: SunSpec Model 714 — DER DC Measurement | ModbusCloud

Registers (13)

13 read / 0 write

Name	Address	Function	Type	Unit	Access
id SunSpec model identifier, fixed value 714 for this model.	0	FC03	uint16		R
l Model length in 16-bit registers following this header.	1	FC03	uint16		R
prtalrms Per-port alarm bitmask, one bit per active DC port.	2	FC03	uint32		R
nprt Number of DC ports reported by this model instance.	4	FC03	uint16		R
dca Total DC current across all ports, amperes.	5	FC03	int16	A	R
dcw Total DC power across all ports, watts.	6	FC03	int16	W	R
dcwhinj Cumulative DC energy injected (exported) to the system, watt-hours.	7	FC03	uint64	Wh	R
dcwhabs Cumulative DC energy absorbed (imported) from the system, watt-hours.	11	FC03	uint64	Wh	R
dca_sf Scale factor for DC current registers, SunSpec signed exponent.	15	FC03	int16		R
dcv_sf Scale factor for DC voltage registers, SunSpec signed exponent.	16	FC03	int16		R
dcw_sf Scale factor for DC power registers, SunSpec signed exponent.	17	FC03	int16		R
dcwh_sf Scale factor for DC energy registers, SunSpec signed exponent.	18	FC03	int16		R
tmp_sf Scale factor for temperature registers, SunSpec signed exponent.	19	FC03	int16		R