hpmont HD20 Series User Manual

Appendix B Communication Protocol Shenzhen Hpmont Technology Co., Ltd
―152― HD20 Series Inverters User Manual
MODBUS adopts “Big Endian” encoding mode, higher byte prior to lower byte at sending.
1) RTU mode
In the RTU mode, the idle time of frame head and frame tail passing bus should be not less than
3.5 bytes, and data checking relies on CRC-16. The whole information need be checked. The
concrete CRC checking is referred to the page 162.
Take RTU data for example: To read internal register F00.08=50.00Hz of No. 1 inverter:
The command frame:
Address
Code
Register Address
Read char no.
Checksum
0x01 0x03 0x00 0x08 0x00 0x01 0x5 0xC8
The response frame:
Address Code Response Byte Content of register Checksum
0x01 0x03 0x02 0x13 0x88 0xB5 0x12
2) ASCII mode
In ASCII mode, the frame head is “0x3A”, while the frame tail default is “0x0D”, “0x0A” and the
frame tail can be set by the users. In ASCII mode, all the data bytes will be sent via ASCII code
except frame head and frame tail, higher 4-byte prior to lower 4-byte at sending. In ASCII mode,
data is 7-byte and for the “A”
－
“F” will adopt their uppercase of the ASCII code. The data adopts
LRC checking, covering the slave address and data. Checksum is the character of data that is
involved in checking and the complement code of carry bit.
Take ASCII data for example: To write 4000 (0x0FA0) to the internal register F00.08 of Slave 1.
LRC checking = the complement code of (0x01+0x41+0x00+0x08+0x0F+0xA0) =0x07
Frame
head
Address Parameter Register address Written content
LRC
checking
Frame tail
Character : 0 1 4 1 0 0 0 8 0 F A 0 0 7 CR LF
ASCII 3A 30 31 34 31 30 30 30 38 30 46 41 30 30 37 0D 0A
5. Scaling of Inverter Transmitting Values
Except the parameters of the remarks, all other function codes can define the scaling relationship
of the specified function code via referring the manual’s minimum unit.
Remarks:
1) Communication data 0
－
2000 of F04.03, F16.05, F16.08, F16.22 and F16.24 corresponds to
data -1000
－
+1000.
2) Communication data 0
－
200 of F16.06 and F16.09 corresponds to data -100
－
+100.
Framehead
Frametail
Data
Checking
Modbus dataframe
ASCII mode
(0x0D,0x0A)
(0x3A)
Slave
address
Function
parameter

hpmont HD20 Series Specifications

General

Brand	hpmont
Model	HD20 Series
Category	Inverter
Language	English