DTSU666 emulation

This mapping emulates a DTSU666 style meter.

Defaults

• Modbus device id: 2

• RS485: 9600 8N1

• Function codes: FC03

• Data types: mixed int16 control registers and float32 measurement registers

Low register block

These are implemented as signed 16-bit style values:

Register	Description	Value
0x0000	software version	204
0x0001	programming code	701
0x0002	power reset	0
0x0003	network selection	0
0x0005	reserved / fixed	0
0x0006	fixed config	1
0x0007	fixed config	10
0x000A	fixed config	0
0x000C	fixed config	0
0x002C	phase mode	3
0x002D	baud selector	depends on baudrate
0x002E	device id	current DevID

Measurement registers

Register	Description	Unit / encoding
0x101E	import energy active	kWh
0x1028	export energy active	kWh
0x2000	line_voltage_l1_l2	V x10
0x2002	line_voltage_l2_l3	V x10
0x2004	line_voltage_l3_l1	V x10
0x2006	voltage_l1	V x10
0x2008	voltage_l2	V x10
0x200A	voltage_l3	V x10
0x200C	current_l1	A x1000
0x200E	current_l2	A x1000
0x2010	current_l3	A x1000
0x2012	active_power_total	W x10
0x2014	active_power_l1	W x10
0x2016	active_power_l2	W x10
0x2018	active_power_l3	W x10
0x201A	reactive_power_total	same sign logic as active total
0x201C	reactive_power_l1	same sign logic as active L1
0x201E	reactive_power_l2	same sign logic as active L2
0x2020	reactive_power_l3	same sign logic as active L3
0x202A	power_factor_total	1000 or -1000
0x202C	power_factor_l1	1000 or -1000
0x202E	power_factor_l2	1000 or -1000
0x2030	power_factor_l3	1000 or -1000
0x2044	frequency	5000 = 50.00 Hz

Device info

Register	Description	Value
0x4006	pre4 meter flag	0 or 1
0x4008	firmware version	packed MMmmpp
0x4010	dongle name	packed P1M3

Notes

• For power registers, export is represented using a negative sign convention.

• This is a targeted subset for inverter compatibility, not a full DTSU666 implementation.