What is a two-bus gas alarm?
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This post was last edited by tiandiyi*an on 2018-3-1 14:09. In short: This device requires only 2 cables to connect the host and the detector. So how should I choose between these two cables? Should I use ordinary shielded cable or twisted pair? To address this issue, we need to base it on the actual situation of the user. If the alarm system purchased by the user uses few detectors, and the distance between the gas alarm controller and the detectors is not great, then ordinary shielded cable is completely sufficient. If the user purchases a large number of detectors and the transmission distance is long, it is highly recommended to use twisted pair cables. This is because twisted pair cables are twisted together, resulting in low distributed capacitance; as a result, they have strong resistance to interference, and signal transmission will not be distorted due to long transmission distances or a large number of detectors connected ； Sheathed cables belong to the parallel wire category; they have a larger distributed capacitance and relatively poor interference resistance, which makes them suitable for short-distance signal transmission.
For a two-wire alarm, the transmission distance is not an issue at all. . . As long as you have the money for wiring, the signal can be transmitted over dozens of kilometers – it’s incredibly simple, as simple as urinating
The 2-wire system should have a terminal; the mA signal goes into this terminal. In the 3-wire system, power is taken from the DCS, and it is fed into the DCS card