modbus 1.3

Modbus TCP Server and Client Programs

Modbus Server and Client programs using Python-3

server.py

client.py

Installation:

sudo pip3 install modbus

Usage Examples:

Server:

sudo python3 -m modbus.server …to run server in commandline

For Register Read, the server sends value starting from 1 and incrementing upto 6000. For example, the client wants to read with FuncCode=3, Address=0, and Length=4. Then the server’s reply for values will be 1,2,3,4 for the first read and values will increment for every subsequent read.

For Coil Reads, the server sends back values 85,86… for the required length.

Client:

python3 -m modbus.client …to run client in commandline

#To run the client within another program or interpreter:

from modbus.client import client

c = client(host=’localhost’) …Change localhost to your IP address

r = c.read(FC=3, ADD=0, LEN=8)

print(“Received Data =”, r)

c.write(FC=16, ADD=0, DAT=[11,22,333,4444]) …DAT should be a list of values