Regarding combustible and toxic gas detectors
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Regarding whether to use a bus-based or branch-based system for combustible and toxic gas detectors, the bus-based system requires much less investment. Some experts now say that a bus-based system should not be used and that a branch-based system is preferable. It doesn’t seem that the new version of 50493 explicitly states that a bus-based system is not allowed. What do everyone think should be done in new projects these days?
The specifications don’t state this explicitly, but experts mentioned verbally during the explanation of the specs that the digital signals in 5.2.1 refer not to buses but to one-to-one hardwired connections. Isn’t that frustrating? It is recommended to use the standard 4–20mA range, or confirm with the local emergency management authorities before implementation
Our new project still uses a separate line connection, linked to the GDS
Buses are for digital signals, which should be clear
You can discuss this with the local emergency management agency to see whether a separate wiring setup, with hardwired connections, is more reliable.