Modbus_tk / tcpslave_example

[Harsha Harish]

Hi All, I'm facing problem to understanding below code. Please help me to explaining. Thanks, Harish. #!/usr/bin/env python
	# -*- coding: utf_8 -*-
	"""
	Modbus TestKit: Implementation of Modbus protocol in python
	(C)2009 - Luc Jean - luc....@gmail.com
	(C)2009 - Apidev - http://www.apidev.fr
	This is distributed under GNU LGPL license, see license.txt
	"""
	import sys
	import modbus_tk
	import modbus_tk.defines as cst
	from modbus_tk import modbus_tcp
	def main():
	"""main"""
	logger = modbus_tk.utils.create_logger(name="console", record_format="%(message)s")
	try:
	#Create the server
	server = modbus_tcp.TcpServer()
	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)
	while True:
	cmd = sys.stdin.readline()
	args = cmd.split(' ')
	if cmd.find('quit') == 0:
	sys.stdout.write('bye-bye\r\n')
	break
	elif args[0] == 'add_slave':
	slave_id = int(args[1])
	server.add_slave(slave_id)
	sys.stdout.write('done: slave %d added\r\n' % 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 added\r\n' % 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: %s\r\n' % 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: %s\r\n' % str(values))
	else:
	sys.stdout.write("unknown command %s\r\n" % args[0])
	finally:
	server.stop()
	if __name__ == "__main__":
	main()