Flammable gas alarm

Is it communication that carries the signal from the alarm to the host?

Determine whether it is 485 or 4-20 milliamps. If it is 485 communication, pay attention to the dialing address as well as the installation location; also consider the installation length, and check whether the power supply has sufficient capacity

Based on the information you provided, the possibilities of an incorrect wiring sequence for the combustible gas alarm, damage to the alarm itself, or abnormal wiring tests have been ruled out. The possible reasons are as follows: 1. Excessive signal transmission distance: The signal transmission range of combustible gas detectors is limited; if the detector is installed too far away from the main unit, it may not be possible for the signal to reach the main unit. You can check whether these faulty alarms are located far away from the main unit. 2. Signal interference: If other electronic devices or power lines are located near these alarms, it may cause signal interference, preventing the signals from being transmitted to the main unit. You can check whether there are any other electronic devices or power cables around the alarm, and try to avoid interference as much as possible. 3. Signal line failure: Although you state that the line test was successful, there may still be issues such as loose or broken connections in the lines. You can check whether the signal wires of these faulty alarms are firmly connected, with no damage or looseness. If the above methods do not resolve the issue, it is recommended that you contact a professional for further inspection and repair. .

With the 485 bus, it’s very likely that the signal is diffraction; add matching resistors