A，　　单发单收，在发送状态，能够连续发送从0到99的数字；

B，　　单发单收，在接收状态，能够接收数据，并在数码管上正确地显示出来；

C，　　单发多收，在AB完成的基础上，接上多个接收设备，能够正确发送和接收

这是从站2的代码-A, single-input single in the sending state, capable of continuously transmitting a number from 0 to 99　B, single-input single in the receiving state, capable of receiving data, and display correctly in the digital tube out　C, single overcharged, on the basis of AB completed, connect multiple receiving devices, capable of sending and receiving the correct code from the station which is 2