E850-DTU(4440-GPRS) datasheet
Copyright ©2012–2018
，成都亿佰特电子科技有限公司
16
Control switch quantity DO output
Function: 05
，
Write a single coil state, 0F, Write multiple coil states
Address range: 00017(0x0010)~00020(0x0013)
Note: When the device relay is passively output, and the coil is not power on, the NC and COM of
the relay are normally closed, the NO and the COM are normally open; when the coil is power on, the
phenomenon is reversed, the relay NC and COM are disconnected, the NO and the COM are closed,.
The state of relay can be controlled by command.
For example:
Function code 0x05 writes DO2 switch output, making NC2, COM2 disconnect, NO2, COM2
close, writing value FF 00; making NC2, COM2 close, NO2, COM2 disconnect, writing value 00.
Modbus RTU protocol write switch output:
Send
01
05
00 11
FF 00
DC 3F
Device ModBus
address
Function
code
Switch quantity
address
Write value
CRC code
Receive
01
05
00 11
FF 00
DC 3F
Device ModBus
address
Function
code
Switch quantity
address
Write value
CRC code
Modbus TCP protocol write switch output:
Send
00 01
00 00
00 06
01
05
00 11
FF 00
Transmi
ssion
identifie
r
Protocol
identifier
Length
Unit
identifie
r
Functi
on
code
Start address
Read number
of switch
quantity
Receive
00 01
00 00
00 06
01
05
00 11
FF 00
Transmis
sion
identifier
Protocol
identifier
Length
Unit
identifier
Functi
on
code
Start address
Read number
of switch
quantity
Function code 0x0F writes DO2, DO3 switch output, making NC2, COM2 disconnected, NO2,
COM2 closed; making NC3, COM3 disconnected, NO3, COM3 closed. Write value should be 0x03,
corresponding to binary bit 0000 0011
Modbus RTU protocol write switch output:
