python modbus控制plc_python 玩转 modbus

import sys

import modbus_tk

import struct

import modbus_tk.defines as cst

from modbus_tk import modbus_rtu

import time

import serial

import threading

PORT = 'com3'

#PORT = '/dev/ptyp5'

def main():

"""main"""

global slave_1

logger = modbus_tk.utils.create_logger(name="console", record_format="%(message)s")

#Create the server

server = modbus_rtu.RtuServer(serial.Serial(PORT))

try:

logger.info("running...")

logger.info("enter 'quit' for closing the server")

server.start()

slave_1 = server.add_slave(1)

slave_1.add_block('0', cst.HOLDING_REGISTERS, 0, 100)

t = threading.Thread(target=updateData)

t.setDaemon(True)

t.start()

while True:

cmd = sys.stdin.readline()

args = cmd.split(' ')

if cmd.find('quit') == 0:

sys.stdout.write('bye-byern')

break

elif args[0] == 'add_slave':

slave_id = int(args[1])

server.add_slave(slave_id)

sys.stdout.write('done: slave %d addedrn' % (slave_id))

elif args[0] == 'add_block':

slave_id = int(args[1])

name = args[2]

block_type = int(args[3])

starting_address = int(args[4])

length = int(args[5])

slave = server.get_slave(slave_id)

slave.add_block(name, block_type, starting_address, length)

sys.stdout.write('done: block %s addedrn' % (name))

elif args[0] == 'set_values':

slave_id = int(args[1])

name = args[2]

address = int(args[3])

values = []

for val in args[4:]:

values.append(int(val))

slave = server.get_slave(slave_id)

slave.set_values(name, address, values)

values = slave.get_values(name, address, len(values))

sys.stdout.write('done: values written: %srn' % (str(values)))

elif args[0] == 'get_values':

slave_id = int(args[1])

name = args[2]

address = int(args[3])

length = int(args[4])

slave = server.get_slave(slave_id)

values = slave.get_values(name, address, length)

sys.stdout.write('done: values read: %srn' % (str(values)))

else:

sys.stdout.write("unknown command %srn" % (args[0]))

finally:

server.stop()

#更新值

def updateData():

global slave_1

while True:

slave_1.set_values('0', 3, 88)

slave_1.set_values('0', 4, 99)

# print(slave_1.get_values('0',3,2))

time.sleep(1)

if __name__ == "__main__":

main()