Hi, I'm using Twisted in an industrial application to replace a multi-threaded C++ driver which I developed some time ago to drive an array of serial ports (COM port expander) simultaneously. This is quite a typical application found in industrial control, building security/access control systems, etc. where an extended multi-drop serial protocol like RS485/422 is used together with a standard message format such as Modbus to do remote data aquisition and control of embedded devices. These kind of systems make use of what is refered to as a master/slave serial driver i.e. there is only one master (typically a PC) and a slave device may only respond to polls from the master. My aim is to create a new Twisted package - say twisted.industrial - which I hope contribute to the Twisted platform. I want to achieve this by extending Twisted without modifying any Twisted sources, reusing as much as possible of existing Twisted code and * doing things very much the "Twisted way" * :) The main problem is that most of Twisted's base classes seems to have TCP/UDP network connectivity in mind. I have managed to subclass SelectReactor in order to create SerialSelectReactor, base.BaseConnector to create SerialConnector, SerialPort to create ExtendedSerialPort and I have the following piece of code working. *********************************************************** if __name__=='__main__': from serialreactor import serialreactor factory = ModbusFactory() factory.protocol=Modbus() serialreactor.connectSerial('/dev/ttyS0',9600,factory) print "start reactor" serialreactor.run() print "exit reactor" *********************************************************** This is good but I want to run more than one serialport (or serial protocol) simultaneously - i.e I need to drive up to 64 serial ports at the same time. I believe I need to do something like: ************************************************************ if __name__=='__main__': from serialapplication import SerialClient,service application=service.Application('Serial',uid=1,gid=1) factory = ModbusFactory() factory.protocol=Modbus() print "start client" internet.SerialClient(79,factory).setServiceParent(service.IServiceCollection(app lication)) print "exit client" ************************************************************** But I'm finding difficulty in grasping the code in application.internet (do not understand why it was done like that) since I want to subclass _AbstractClient which is seems to be the product of some clever text manipulation and dynamic "class creation". Any comments, suggestions, recommendations and am I one the right track? regards, Eugene