Ebyte E821-RTU, Руководство пользователя

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Chengdu Ebyte Electronic Technology Co.,Ltd E821-RTU (0400-ETH)User Manual
Copyright ©2012–2019, Chengdu Ebyte Electronic Technology Co.,Ltd
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4.2 RTU basic function
4.2.1 Read analog-data AI input
Function code: 03, Read hold-register; 04, Read input-register
Address range: 30017(0x0010)~30020(0x0013)
Remark: The unit of analog input value is uA
E.g.:
Function code 0x03, read AI1 input, assuming AI1 input is 9946uA, the corresponding value should be 0x26 DA
Modbus RTU protocol read analog-data input:
Send
01 03 00 13 00 01 75 CF
Device ModBus
address
Function
code
Analog-data start
address
Read the number of
addresses
CRC check code
Receive
01 03 02 26 DA 23 BF
Device ModBus
address
Function
code
Number of bytes
returned
Analog-data input
value
CRC check code
Modbus TCP protocol read analog-data input:
Send
00 01 00 00 00 06 01 03 00 13 00 01
Transmiss
ion
identifier
Protocol
identifier
Length
Unit
identifier
Functio
n code
Analog-data start
address
Read the number
of addresses
Receive
00 01 00 00 00 05 01 03 02 26 DA
Transmiss
ion
identifier
Protocol
identifier
Length
Unit
identifier
Functio
n code
Number of bytes
returned
Analog-data input
value