Specifications

The STB NIB 2212 NIM Module
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Selecting a Source Power Supply for the Island’s Logic Power Bus
Logic Power Requirements
An external 24 VDC power supply is needed as the source for logic power to the
island bus. The external power supply connects to the island’s NIM. This external
supply provides the 24 V input to the built-in 5 V power supply in the NIM.
The NIM delivers the logic power signal to the primary segment only. Special
STB XBE 1300 beginning-of-segment (BOS) modules, located in the first slot of
each extension segment, have their own built-in power supplies, which provide logic
power to the STB I/O modules in the extension segments. Each BOS module that
you install requires 24 VDC from an external power supply.
Characteristics of the External Power Supply
The external power supply needs to deliver 24 VDC source power to the island. The
supply that you select can have a low range limit of 19.2 VDC and a high range limit
of 30 VDC. The external supply must be rated safety extra low voltage (SELV-rated).
The SELV rating means that, in addition to basic insulation between hazardous
voltages and the DC output, a second supplementary insulation layer has been
added. As a result, if a single component/insulation does not perform, the DC output
does not exceed SELV limits.
Calculating the Wattage Requirement
The amount of power (see page 38) that the external power supply must deliver is
a function of the number of modules and the number of built-in power supplies
installed on the island.
The external supply needs to provide 13 W of power for the NIM and 13 W for each
additional STB power supply (like an STB XBE 1300 BOS module). For example, a
system with one NIM in the primary segment and one BOS module in an extension
segment would require 26 W of power.
CAUTION
IMPROPER GALVANIC ISOLATION
The power components are not galvanically isolated. They are intended for use
only in systems designed to provide SELV isolation between the supply inputs or
outputs and the load devices or system power bus. You must use SELV-rated
supplies to provide 24 VDC source power to the NIM.
Failure to follow these instructions can result in injury or equipment damage.