Similar to the short message receiving function of TV station.

It is realized by SMS (a kind of hardware).

The so-called short message cat is actually a device for sending and receiving short messages. Just like the mobile phone we use, we need the support of the SIM card. When you need to send and receive short messages, you can insert a mobile phone card that we usually use in the short message cat, plug in the power supply, and connect with the computer through the data cable (USB or serial port or network port), so that you can realize the function of sending and receiving short messages in the application management software of the computer.