Ebyte E150-400T30S, User Manual

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Chengdu Ebyte Electronic Technology Co.,Ltd.
E150-400T30S user manual
Copyright ©2012–2022
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Chengdu Ebyte Electronic Technology Co.,Ltd.
10
Chapter 5 Introduction to Modbus RTU Commands
Modbus RTU has a total of 8 function codes (hexadecimal), and their meanings are as follows:
function code illustratation function code illustration
01 Read coil status 05 write coil status
02 Read discrete input 06 write a single register
03 read holding register 0F write multiple coils
04 read input register 10 write multiple registers
E150-400T30S modules can communicate with E22-400Txxx series modules wirelessly, but the following
conditions must be met:
Both modules need to work in "transparent mode";
The parameters of "air rate", "channel address", "module address" and "network number" of both modules
must be consistent;
The following commands related to remote wireless communication must meet the above conditions.
5.1 Read coil status
Using the read coil status (01) function code to read the output coil status, for example: read the status of
do1 ~ do4
01 01 00 00 00 04 3D C9
Device MODBUS
address
Function code Register
head address
Number of output
coils read
CRC check
code
CRC check code note: the CRC check code of the last two bytes of the sending instruction needs to be calculated
by the user.
Serial port sending: 01 01 00 00 04 3D C9
Remote wireless transmission: 01 01 00 00 00 04 3D C9
After the above command is sent to the device through the serial port or wireless, the device will return the
following values to the serial port or wireless:
01 01 01 0F 11 8C
Device MODBUS
address
Function code Number of
bytes of data
Returned status
data
CRC check
code
The returned status data 0f indicates that the outputs do1 to do4 are at a high level.
Serial port receiving return value: 01 01 01 0f 11 8C