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King Pigeon Hi-Tech. Co., Ltd.
Ver 1.3
GSM/SMS/GPRS/3G/4G
Cellular IoT Gateway
Write Data
2
00 64H
Data writing value is Decimal data 100
16 CRC Verify
2
9E C3H
CRC0 CRC1 low byte in front, high behind
Receiver Return Data Format:
Content
Bytes
Data
(H: HEX)
Description
Device Address
1
01H
01H Device, according to the data Master send
Function Code
1
06H
Write single holding register
Mapping Register
Address
2
4E 20H
Address range: 4E20H-501CH, mapping data type
address range.
Write Data
2
00 64H
Write 100 successfully
16 CRC Verify
2
9E C3H
CRC0 CRC1 low byte in front, high behind
Example: If address 20000 mapping slave data type is Signed Int, sort AB, modify mapping address 20000
register to 100, then:
Server send:
01 06 4E 20 00 64 9E C3
01= Device address; 06= Modify single holding register value; 4E 20=Modify address 20000 register value; 00
64 = Write Decimal value 100;
9E C3 = 16 Bit CRC verify.
Device answer:
01 06 4E 20 00 64 9E C3
01= Device address; 06= Modify single holding register value; 4E 20= R Modify address 20000 register value;
00 64= Modify to Decimal value 100.
9E C3 = 16 Bit CRC verify.
If need to modify multi data type mapping address, pls check function code 16 in Modbus protocol.
8.5 Modbus TCP Master Application
When Ethernet as Modbus TCP master,can extend I/O tags, support slaves for connecting Remote I/O data
acquisition module, Smart meter, Power monitoring module, Smart transducer... Can mapping register value
from Slave to Master, these registers’ can be setup high or low threshold value, and NC/NO type, moreover,
can enable to send SMS to users once alarm occurrence by the registers if required. Also can remote control
Slaves by writing coil.
For example, when device as Modbus TCP master,as below:
1)Ethernet Setting:
In “Ethernet Settings” page, choose correct slave IP and port,click “save” to add,support up to 5 Ethernet
slave.
