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2016
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9 - Connecting uLINK hardware
uLINK hardware contains two types of devices, uLINK HUB and uLINK modules.
uLINK HUB
The uLINK HUB serves as a concentrator
and isolated power source for SMD boxes
connected to the uLINK bus. Up to four
SMDs can be connected to one uLINK HUB.
uLINK HUB is a basic element of the uLINK
network and every setup must contain at
least one.
The uLINK HUB enclosure is an industrial
standard 100mm wide case designed to be
mounted onto DIN rail. Terminals are
removable, however we do not recommend
removing them for other than emergency
purposes,
troubleshooting, or
setup to avoid unnecessary stress to the
circuit boards.
CAT5 wire color
uLINK DB9M
pin number
uLINK HUB
SMD terminals
Orange
3
A'
Orange/White
7
B'
Blue
5
R
Blue/White
9
R
Green
3
A
Green/White
7
B
Brown
4
+
Brown/White
1
+
Shield
SHELL
SH
Each SMD is connected to the uLINK HUB
by single, shielded CAT5/6 cable, but each
connection uses two wire pairs to maintain
the daisy-chain topology. The third and fourth pairs are used to provide galvanically isolated power for the uLINK
circuits in the SMD in order isolate the uLINK bus from any other circuits, minimize interference, and maximize
RFI immunity. Power pairs are connected in parallel to minimize voltage losses.
NOTE:
When designing the uLINK bus, don't forget to include twice the length of the cables from the uLINK HUB
to each SMD in the total length of the uLINK bus.
IMPORTANT:
Unused SMD ports on the hub cannot remain unconnected. Unused ports data terminals must be
looped with jumpers from A to A' and from B to B' as shown on drawing.
uLINK HUB can be placed anywhere in the network, however the most practical location it at one end of the
uLINK bus as shown above. When the hub is placed at one end of the bus, the bus can be directly terminated
on the HUB terminals.
94
Example of uLINK HUB wiring, located at one end of the iLINK bus
