Gas alarm controller generally refers to the host. Because there is no specific model can not help you determine the type of signal line. General bus host using the basic 485 signal. The use of RVVSP cable. There are also special hosts can not use shielded twisted pair cable, that is, using RVV cable.
Detectors generally 3 to 5 years to be replaced. The host is generally replaced in about 5 years.