Low Voltage Nodes

The LV Nodes interconnect junction boxes and their associated instrument platforms to Primary Nodes. They are key to the expansion capability of the system by allowing a single input from a Primary Node to be distributed to multiple outputs. In the initial RSN architecture there will be approximately five LV Nodes deployed. The design allows the addition of more LV Nodes over the 25-year life of the OOI to expand the coverage area and number of sensors. Connections to LV Nodes are made using ROV wet-mateable connectors so that the LV Node can be brought to the surface for maintenance and repair without having to recover the cables or other attached infrastructure.

The nominal input voltage to the LV Node is 375 Vdc and the input data link is 1 GigE. There are two expansion ports that pass on the 375 Vdc and have a 1 GigE data link. These ports can either be connected to another LV Node for expansion, to a Medium Power J-Box, or to other specialized equipment that requires higher power or bandwidth, e.g., inductive power coupler systems in docking stations for charging batteries in mobile platforms, or high-definition cameras. In addition, the LV Node has four science ports that provide 48 Vdc and has 10/100BASE-T data links, which provide connections to Low Power J-Boxes. The inputs and outputs will also have a timing pulse per second link that is passed from inputs to outputs. This link will also have a low bandwidth out of band control protocol to talk to the node controller in case the In Band data path is not working.