The example use XMLRPC call but the same approach could also be done with JSON-RPC. And also in other frameworks like NodeJS if the implemitation is JavaScript language.

If you need a client to make XMLRPC call you could use postman https://www.postman.com/

from twisted.web import xmlrpc, server

from twisted.logger import Logger

import logging

import snap7

logging.basicConfig(level=logging.INFO)

logger = logging.getLogger(__name__)

plc = snap7.logo.Logo()

## <ip_address, tsap_snap7 (client) 03.00 = 0x0300, tsap_logo (server) 02.00 = 0x0200>

plc.connect("192.168.0.2", 0x0300, 0x0200)

# vm_address = ("V1107.4") #V1104.N[0-7]

# w = plc.write(vm_address, 0)

# r = plc.read(vm_address)

# print(f"M29: {str(r)}")

class logo_func(xmlrpc.XMLRPC):

def xmlrpc_logo_write(self, *args):

if list(args[0].keys()) == ['m29']:

vm_address = "V1107.4"

# write 'm1' to 0 or 1

w = plc.write(vm_address, args[0]['m29'])

# read the address and print status

r = plc.read(vm_address)

status = (f"M29: {str(r)}")

print(status)

# response status of xmlrpc call

return status

def xmlrpc_fault(self):

"""

Raise a Fault indicating that the procedure should not be used.

"""

raise xmlrpc.Fault(123, "The fault procedure is faulty.")

def handleData(data):

log.debug("Got data: {data!r}.", data=data)

if __name__ == '__main__':

from twisted.internet import reactor

r = logo_func()

reactor.listenTCP(7080, server.Site(r))

reactor.run()

I'm macOS user so I also include a AppleScript that could make XMLRPC call.

tell methodCall

set memoryBit_1 to its methodName:"logo_write" params:{m29:0} --> or m29:1

end tell

script methodCall

on methodName:methodName params:params

tell application "http://localhost:7080"

call xmlrpc {method name:methodName, parameters:params}

end tell

end methodName:params:

end script

Here is 'hello world' for Siemens LOGO :) 

tell methodCall

repeat 5 times

set memoryBit_1 to its methodName:"logo_write" params:{{m29:true}}

delay 2

set memoryBit_1 to its methodName:"logo_write" params:{{m29:false}}

delay 2

end repeat

end tell

script methodCall

on methodName:methodName params:params

tell application "http://localhost:7080"

call xmlrpc {method name:methodName, parameters:params}

end tell

end methodName:params:

end script