Rayleigh Instruments RI-F220-C Modbus register map

Rayleigh RI-F220-C three-phase panel meter with RS-485 Modbus RTU

Official
101 registers
Modbus RTU
Revision 2 · 2026-10-17
Identity: serial number

Official: Written from the manufacturer's documentation, but not tested on a device yet. Check the map against the manufacturer's documentation before you write to a live device. Tested it? Report a test.

Download .mbmap.json Raw JSON View on GitHub Suggest a correction Report a problem

Communication

Protocol: Modbus RTU
Unit ID: 1
Serial: 9600 8N1 · 9600 baud, 8 data bits, none parity, 1 stop bit
Byte / word order: CDAB · bytes big-endian, words low first (word swap)
Addresses: 0-based

Connection values are defaults: the device may be configured differently.

Map

Registers: 23 holding registers, 78 input registers
Groups: 2
Revision: 2 · 2026-10-17
Added: 2026-10-14 (2026-10-14)
File: maps/rayleigh-instruments/ri-f220.mbmap.json · 17 KB · history
SHA-256: e55f2764a461749142dc318fc088955ba553f3709e585cb2617d135985b51b7e
Manufacturer: rayleigh.com

Device identity

What a tool can read to check that this map fits the connected device (SPEC.md section 4.7). Registers with a role are read like any other register.

Registers
Role	Register	Address	Type	Values
Serial number	Serial No.	input 684	uint32 CDAB

Sources and notes

RI-F220-C Modbus Registers · version V01

Source: Rayleigh Instruments, "RI-F220-C Modbus Registers", RI-F220-C-COMM V01

Defaults: address 1, 9600 baud, 8 data bits, no parity, 1 stop bit. Baud rates 300 to 19200.
Floats are sent low word first (the table's FLOAT REVERSE WORD); a setting in the setup registers can change this.
The table numbers measurements 3xxxx and settings 4xxxx and gives the PDU address in hex; this map reads them as input and holding registers at those addresses. The table also says to add 1 to the address for function 3 holding-register access, so check the addressing on the device.
The integer (HEX) copies of the measurements are not included: the table does not give their scaling.
Settings that take a decimal range (pulse duration, pulse weight) are listed without a scale because the table does not give one.

Area	Address	Type	Access	Unit	Description
IR	0	float32 CDAB	R	V
IR	2	float32 CDAB	R	V
IR	4	float32 CDAB	R	V
IR	6	float32 CDAB	R	V
IR	8	float32 CDAB	R	V
IR	10	float32 CDAB	R	V
IR	12	float32 CDAB	R	V
IR	14	float32 CDAB	R	V
IR	16	float32 CDAB	R	A
IR	18	float32 CDAB	R	A
IR	20	float32 CDAB	R	A
IR	22	float32 CDAB	R	A
IR	24	float32 CDAB	R	kW
IR	26	float32 CDAB	R	kW
IR	28	float32 CDAB	R	kW
IR	30	float32 CDAB	R	kVA
IR	32	float32 CDAB	R	kVA
IR	34	float32 CDAB	R	kVA
IR	36	float32 CDAB	R	kvar
IR	38	float32 CDAB	R	kvar
IR	40	float32 CDAB	R	kvar
IR	42	float32 CDAB	R	kW
IR	44	float32 CDAB	R	kVA
IR	46	float32 CDAB	R	kvar
IR	48	float32 CDAB	R
IR	50	float32 CDAB	R
IR	52	float32 CDAB	R
IR	54	float32 CDAB	R
IR	56	float32 CDAB	R	Hz
IR	58	float32 CDAB	R	kWh
IR	60	float32 CDAB	R	kVAh
IR	62	float32 CDAB	R	kvarh
IR	64	float32 CDAB	R	kW
IR	66	float32 CDAB	R	kW
IR	68	float32 CDAB	R	kvar
IR	70	float32 CDAB	R	kvar
IR	72	float32 CDAB	R	kVA
IR	74	float32 CDAB	R	A
IR	76	float32 CDAB	R	A
IR	78	float32 CDAB	R	A
IR	80	float32 CDAB	R	A
IR	82	float32 CDAB	R	hrs
IR	84	float32 CDAB	R	kWh
IR	86	float32 CDAB	R	kWh
IR	88	float32 CDAB	R	kWh
IR	90	float32 CDAB	R	kWh
IR	92	float32 CDAB	R	kWh
IR	94	float32 CDAB	R	kWh
IR	96	float32 CDAB	R	kWh
IR	98	float32 CDAB	R	kWh
IR	100	float32 CDAB	R	kvarh
IR	102	float32 CDAB	R	kvarh
IR	104	float32 CDAB	R	kvarh
IR	106	float32 CDAB	R	kvarh
IR	108	float32 CDAB	R	kvarh
IR	110	float32 CDAB	R	kvarh
IR	112	float32 CDAB	R	kvarh
IR	114	float32 CDAB	R	kvarh
IR	116	float32 CDAB	R	kVAh
IR	118	float32 CDAB	R	kVAh
IR	120	float32 CDAB	R	kVAh
IR	124	float32 CDAB	R	%
IR	126	float32 CDAB	R	%
IR	128	float32 CDAB	R	%
IR	130	float32 CDAB	R	%
IR	132	float32 CDAB	R	%
IR	134	float32 CDAB	R	%
IR	136	float32 CDAB	R	%
IR	138	float32 CDAB	R	%
IR	140	float32 CDAB	R	%
IR	684	uint32 CDAB	R		Read as hexadecimal
IR	686	float32 CDAB	R
IR	688	uint32 CDAB	R
IR	692	float32 CDAB	R	kW
IR	694	float32 CDAB	R	kvar
IR	696	float32 CDAB	R	kVA
IR	698	float32 CDAB	R	kW	The table prints the decimal register number twice; the hex address is used
IR	700	float32 CDAB	R	kvar
HR	0	uint16	RW		Default 1000
HR	1	uint16	RW		Default 0
HR	2	uint16	RW	A	1 or 5. Default 5
HR	3	uint16	RW	A	CT Sec = 1: 1 - 10000. Default 5
HR	4	uint16	RW	V	Default 350
HR	5	uint32 CDAB	RW	V	Default 350
HR	7	uint16	RW		Default 1
HR	8	uint16	RW		Default 5
HR	9	uint16	RW		Default 0
HR	10	uint16	RW		Default 0
HR	11	uint16	RW	s	Default 0
HR	12	uint16	W		1: Set to factory setting range
HR	13	uint16	W		1: Reset total active energy
HR	14	uint16	W		1: Reset total apparent energy
HR	15	uint16	W		1: Reset total reactive energy
HR	16	uint16	RW		Default 0
HR	17	uint16	RW		Default 15
HR	18	uint16	RW	min	Default 1
HR	19	uint16	W		1: Reset max/min demand
HR	20	uint16	W		1: Reset run hour
HR	21	uint16	W		1: Reset aux interrupt
HR	22	uint16	RW		0.01 - 99.99. Default 0.1

Help improve this map

I tested it on a deviceReport whether it worked, even if you did not write the map.
Suggest a correctionEdit the file on GitHub; it opens a pull request.
Report a problemA wrong address, type, scale or byte order.
Read the formatWhat each key of the file means (SPEC.md).