modbus_tcp_client#
Overview#
This example demonstrates how to use Modbus TCP protocol to control board LED light.
FreeModbus supports bellow feature:
Read coil(0x01)
Read discrete inputs(0x02)
Read holding registers(0x03)
Read input registers(0x04)
Write single coil(0x05)
Write single holding register(0x06)
Write board LED status(0x0d)
Read board LED status(0x0e)
Write multiple coils(0x0f)
Write multiple holding registers(0x10)
Running the demo#
If the test passes, serial port output:
Please input Modbus Server ip address(for example 192.168.1.2):
Note: don't use backspace key or space key!
Modbus Server ip: 10.91.20.33
Initializing PHY...
[LINK STATE] netif=0, state=down
[LINK STATE] netif=0, state=up, speed=100M_full
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Modbus TCP example
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FOR TASK ETH Get IP address from DHCP...
IPv4 Address : 10.91.20.66
IPv4 Subnet mask : 255.255.255.0
IPv4 Gateway : 10.91.20.254
Enable LED1
0 1 0 0 0 6 1 13 0 0 0 1
Enable LED2
0 1 0 0 0 6 1 13 0 1 0 1
...
Use the MIMXRT1180-EVK board as modbus Server simulator, write board LED status(0x0d) to control LED light