Modbus protocol instructions

Using RS485 communication interface, the baud rate is fixed at 9600, the data bits are 8 bits + 1 stop bit, no parity bit; the default local address is 63; the specific protocol is as follows:

1.Device address: can be set between1~63

2.Only supports 03 and 06 commands of MODBUS protocol

3.Holding register definition

Address	Range	Unit	Definition	Remarks
0x0001	0~1000	0.1Hz	Current output frequency value	Read only
0x0002	0~255	0.1A	Current output current value	Read only
0x0003	0~1000	V	Current input voltage value	Read only
0x0004	-10~125	℃	Current temperature display	Read only
0x0005	0~2400	0.01BAR	Actual pressure value	Read only
0x0006	0~31		Error code	Read only
0x0007	0~3		Status code	Read only
0x0010	0~1		Restore factory value
0x0011	10~200	0.01BAR	Starting pressure difference
0x0012	0~2360	0.01BAR	Water shortage pressure value
0x0013	0~60	Second	Water shortage time
0x0014	72,76	72:H 76:L	Carrier frequency
0x0015	20~50	0.1ms	Acceleration and deceleration time
0x0016	0~100	0.01BAR	Allowable pressure error
0x0017	200~400	0.1Hz	Minimum frequency of shutdown
0x0018	0~1		Allow non-stop
0x0019	6,10,16,25	BAR	Measuring range selection
0x0020	60~91	℃ (91 for H)	Over temperature setting
0x0021	0~1		Set direction
0x0022	1~63		Local address
0x1000	0~2400	0.01BAR	Set pressure value
0X1001			KEY value, support key value 0x00: invalid 0x01: running 0x04: stop 0x11: fault clear

4. Fault code definition (register address 0x0006)

Error code	Definition
0	Indicates no fault
1	Indicates hardware overcurrent, short circuit
2	Indicates overload
3	Indicates underpressure (no pressure sensor)
4	Indicates excess pressure
5	Indicates underpressure
6	Indicates excess pressure
7	Indicates phase loss (power phase loss)
8	Indicates overtemperature
9	Indicates insufficient power
10	Indicates software overcurrent
11	Indicates communication failure
12	Default
13	Indicates that the motor is blocked
14	Indicates motor phase loss
15	Indicates motor overspeed
16	Indicates memory failure (FLASH failure)