1-8 channel gas control alarm host

The RA900 series is a two-channel/four-channel/eight-channel gas alarm controller. It consists of universal metal shell, switching power supply, motherboard, interface board, alarm and other parts. The display part is composed of 0.8 inch digital tube, which displays the concentration of each channel in turn. The display is clear and can adapt to different light environment. At the same time, the channel state information is indicated. The key part consists of a number of high-quality keys, which feel good when pressed and effectively improve the user's operating feel. In program design, high safety key trigger scheme is adopted - press down to start the identification key, release to complete the identification. The key signal below 20ms is invalid, the key signal between 20ms and 3 seconds is normal, and the key signal over 3 seconds is long press. With sound and light alarm (optical alarm optional), multiple groups of alarm relay output.