ATC-873 wireless digital transmission module offers standard RS-232, RS-485 and UART/TTL level interfaces for direct connection with computers, use’s RS-485 equipments, SCM or other UART parts. ATC-873 has adopted half duplex communication channel most suitable for point to multi-point communication mode. The primary station takes full control of communication harmony, and adopts data frames with address codes for data or command transmitting. The secondary station shall fully receive them and select response by comparing address codes; all the work shall be fulfilled by upper layer protocols, which shall ensure that only one wireless module in the communication network is in the transmitting state in any instant to avoid mutual interference. Therefore, the transmission channel built by ATC-873 is transparent to the user. ATC-873 can also be applied to point to point communication, making it easier and smoothly upgrade wire (RS232/485/TTL) transmission mode in original system. 1, low power data transmission. 2, visual distance transmission distance up to 300 m (863), 500 m (871), 1 km (873), 2 km (875). 3, based on FSK/GFSK way of debugging, efficient communication protocols, good reliability, low bit error rate. 4, data transparent transmission, transmission is longer than the data frame. 5, colleagues provide RS – 232 / RS – 485 / TTL level interface, optional I/O port. 6, can be used to point to point, point to many, many to point communication mix a variety of ways. 7, only data control, users need extra program. 8, carrier frequency 433 MHZ, also can provide 315/868/915 MHZ carrier frequency. 9, watchdog fact monitoring, an external antenna is optional.