TCI - Transceiver Control Interface was developed by Expert Electronics company, for simple and still advanced connection between the ExpertSDR2 and third-party software. TCI has all required control commands similar to CAT system, but even more, it can transfer IQ-streams from the ExpertSDR2 to clients (third-party software such as signal Skimmers, etc) via local network and the Internet, CW macroses and Audio In/Out streams for digital modes (will be added soon). TCI is the universal multi-client interface (you can connect it to radio Loggers, Skimmers, PAs, Ant.switches etc. at the same time). It was developed as an open protocol to use with multi-brand transceivers, which support one, two or multi receivers/transmitters. This is a game changer for the SDR radio!
It is an open source protocol, we've discussed using it with hardware and accessory developers. For example, Band Pass Filters unit with LAN interface can get information about radio frequency via LAN and can switch filters, the same applies to antenna switches and PAs and so on.
We will try to get TCI into all HAM software, currently, we have agreements with several developers - N1MM, MixW, 5M Contest, LogHX.

Connection process with TCI is very easy, someday in the future, you won't believe you lived without it for so long! - link to the list of files with description of the interface in English and Russian and source code of the demo-client software with TCI support.