Ebyte E831-RTU User Manual page 15

01
Transmis
Device ModBus
sion
Address
01
Receivin
Device ModBus
g
Address
Function code 0x0F writes DO2 and DO3 digital output. The write value should be 0x03,
corresponding to the binary bit 0000 0011. (Note that the initial address here starts from DO2.)
Modbus RTU protocol write digital output：
01
Transmis
Device ModBus
sion
Address
01
Receivin
Device ModBus
g
Address
4.2.2. Read switch value DI input
Function code: 02，Read（switch value）input status
Address range: 10017(0x0010)~10020(0x0013)
Description: The device defaults to dry contact input. When DI and DIG are short-circuited, the read
value should be 1. When DI and DIG are not short-circuited, the read value should be 0.
Example:
Read 4 digital input values. DI input terminal DI1 and DIG are short-circuited, DI2 and DIG are
not short-circuited, DI3 and DIG are short-circuited, DI4 and DIG are not short-circuited. The read
digital input value is 0x05, corresponding to the binary bit 0000 0101. The 4 bits represent the digital
input value, which are DI4, DI3, DI2, and DI1 in order.
Modbus RTU protocol read digital input：
01
Transmis
Device ModBus
sion
Address
05 00 11
Function Switch value
code address
05 00 11
Function Switch value
code address
0F 00 11
Switch
Function
value
code
address
0F 00 11
Switch
Function
value
code
address
02 00 10
Function Switch value
code initial address
FF 00
Write value
FF 00
Write value
00 02 01
Write Bytes
switch value numbe
numbers rs
00 02
Write value
00 04
Read switch value
numbers
DC 3F
CRC parity code
DC 3F
CRC parity
code
03 62 95
Write CRC
value parity code
84 0F
CRC parity code
78 0C
CRC parity code