ST950S Plus+ Installation and Commissioning Manual
2.1.3. Nodes and Bypass Module
An example of a Node is the RAG* Node. This is typically fitted inside the green aspect of the Helios
signal. It operates as a fail-safe unit which ensures that the LED signals are guaranteed to be off in the
event of any malfunction.
Figure 3. Bypass Module and RAG Node
The RAG Node is provided with a cover to give some mechanical protection and has several status
LEDs. which indicate the operational status of the Node. The RAG Node PCB is conformally coated to
provide additional protection and improve reliability.
A Bypass Module is included which plugs into the RAG Node. The Bypass Module allows for the
continuation of the Plus
+
communications and operation even if a RAG node has been disconnected
(PL4) for example in the case of a ‘hot’ swap. The Bypass Module also provides addressing functions
in order to assist the controller in the management of Nodes.
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