USR-K7 User Manual www.usriot.comJinan USR IOT Technology Limited 4 / 120 inquiry@usriot.com4.2. Socket ................................................................................................................................................................ 244.2.1. TCP Client mode ..................................................................................................................................... 264.2.2. TCP Server Mod ...................................................................................................................................... 304.2.3. UDP Client mode..................................................................................................................................... 334.2.4. UDP Server mode ................................................................................................................................... 374.2.5. HTTPD client ........................................................................................................................................... 404.2.6. Websocket .............................................................................................................................................. 424.2.7. USR-VCOM .............................................................................................................................................. 454.3. Serial Function ................................................................................................................................................... 464.3.1. Serial port Basic Parameters ................................................................................................................... 464.3.2. Flow Control ........................................................................................................................................... 474.3.3. Serial Port Mapping ................................................................................................................................ 484.3.4. Similar RFC2217 ...................................................................................................................................... 494.4. Special Function................................................................................................................................................. 524.4.1. Heartbeat Package Function ................................................................................................................... 534.4.2. Modbus Gateway .................................................................................................................................... 544.4.3. Registration Package ............................................................................................................................... 554.4.4. USR-cloud ............................................................................................................................................... 574.4.5. Net Printing............................................................................................................................................. 604.4.6. Customize Webpage ............................................................................................................................... 614.4.7. Customize MAC....................................................................................................................................... 624.4.8. Restart Timeout ...................................................................................................................................... 63