Com Port Emulator
Com Port Terminal Emulator
If you are using IIS Express you may need to bind to all hostnames instead of just `localhost’. Check this fine answer: Tell IIS Express itself to bind to all ip addresses and hostnames. 
In your.config file (typically%userprofile% My Documents IISExpress config applicationhost.config, or $(solutionDir).vs config applicationhost.config for Visual Studio 2015), find your site’s binding element, and add Make sure to add it as a second binding instead of modifying the existing one or VS will just re-add a new site appended with a (1) Also, you may need to run VS as an administrator. “BadRequest” is an error which usually got send by the server itself, see 10.4.1 400 Bad Request The request could not be understood by the server due to malformed syntax. The client SHOULD NOT repeat the request without modifications. So you got a working connection to the server, but your request doesn’t fit the expecet form. I don’t know how you create the connection, what headers are included (if there are any) – but thats what you should checking for.
Free Virtual Serial Port Emulator
Operating system: Windows 2000, XP, Vista (32/64), Windows 7; FREE license for 32 bit platform (x86) Virtual Serial Ports Emulator is a FREEWARE program on 32 bit platform and can be used absolutely free for any purpose. Create virtual serial port, connect with virtual null-modem through the network. Emulator and connect it to your software through a pair of virtual COM ports. Virtual Serial Ports Emulator is designed to solve compatibility issues with older applications and help you create and use several serial ports at the same time, without having to install.