Integration with another control system

I am trying to integrate ST with another control system. I need to have the ST send a string such as “command1” to ipaddress:port where the ip address and port are forwarded already in my router.
In my other system, i need to specify what IP or hostname I am communicating with. I know there is no local control currently, is there a work around? If I specify the local IP address of the ST, all I get back is "Password"
Anyone want to help with the code?

SmartApps can communicate with external systems using HTTP. See documentation here: This has been discussed quite extensively in the forums. Just search for it. If you need to talk to a control system on your LAN, you’ll have to expose it to Internet through port forwarding and dynamic DNS (or static IP). There’s also a way to create a custom REST endpoint if you want your system to send HTTP request to ST server. Check out this tutorial: