| DESCRIPTION
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| This is an ARCNET hub with diagnostic LEDs and linking ports. The CT-N900 series of hubs was created to fill a
need for an ARCNET hub with additional diagnostic capabilities for tracking down reconfiguration problems
without resorting to the complexity and cost of an "Intelligent Hub". These hubs are built to withstand a wide
range of industrial temperatures. The hubs maintain full output levels even when running at maximum
temperature and data traffic loads. This stability is
provided through the use of a switching regulator in
the power supply and attention to detail in the output
driver section. The switching regulator produces less
heat and withstands brownouts better than a linear
regulator. Proper thermal design ensures that heat
produced in the output drivers is dissipated via
convection air currents in any acceptable mounting
position.
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| OPERATING ENVIRONMENT
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| Power:
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120 VAC +6%/- 10% @ l60 mA
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| 240 VAC +6%/- 10% @ 80 mA
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| 50 Hz or 60 Hz
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| Operating Temperature:
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-40°C to +75°C
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| Humidity:
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0% to 95% (non-condensing)
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| ARCNET LAN INTERFACE
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| Wavelength:
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820nm to 850nm
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| Connectors:
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Two ST connectors per port (Transmit [Tx] and Receive [Rx])
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| Max. Receiver Input Power:
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-7.6dBm @ 25oC, -8.2dBm @ 85oC
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| Optical Power Budget:
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| PHYSICAL SPECIFICATIONS
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| Height
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2.75 inches
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| Width
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8.5 inches
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| Depth (including connectors)
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7.5 inches (including connectors)
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| Weight
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5 pounds
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| Included with the hub are two mounting brackets and four bolts for attaching the brackets to the hub. A link
cable and one terminator are included for expanding the hub configuration to add more ports or to connect hubs
with different types of media. A detachable power cord is also included.
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| Fiber Optic Cable Type
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| Dual Fiber
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| Graded Index (Multi-Mode)
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| 62.5/125µm or 100/140µm
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| ST connectors
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| Cable specifications include a standard connector loss for both ends of a single cable. It is recommended to allow
2dB of loss to allow for dirt and cracks in the connectors for any given link. Each fusion splice typically adds 0.25
dB loss, and barrel connector splices are the sum of the barrel connector and two end connector losses. All these
factors result in loss along the line and must be considered.
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| Maximum Distance per Segment
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| A segment is the cable between two hubs or a hub and a card on the network. The maximum length of a segment of
fiber optic cable is dependent on the quality, size, connectors, splices and rating of the fiber optic cable. The most
important fiber optic cable specification is the attenuation per kilometer. In combination with the link budget shown
previously, the maximum segment length can be calculated.
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| For example, consider a fiber optic cable with the following specifications:
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| 62.5/125µm
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| Maximum attenuation 3.0 dB/Km
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| No splices in entire cable length
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| ST connectors on both ends
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| Grade F, OFNR (UL Listed Riser)
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| 850 nm
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| From the Optical Power Budget chart the recommended Link Budget is 9.9 dB. Allowing the recommended
2 dB margins, the maximum segment length is then:
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| Maximum Network Span
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| The maximum span defines the longest signal path length between any two nodes in the network. This determines
the maximum end to end propagation delay. ARCNET controller chips have several internal timers based on the
maximum propagation delay for a particular timeout level. A signal is allowed to pass through up to ten hub delays
plus 2000ft [609m] of a coax cable at each segment to determine the standard propagation delay times. This
becomes 22,000ft. [6705m] for a coax network. Since the velocity of propagation is lower in fiber optic cable, the
network span is reduced. The maximum span for a network connected entirely with fiber optic cable using standard
time-outs is approximately 18,500 ft. [5600 meters].
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| Mounting
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| 19" EIA rack mountable
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| wall mountable
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| stackable (up to 4 hubs)
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| CONFORMS TO THE FOLLOWING STANDARDS
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| ARCNET:
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ANSI 878.1
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| EMC:
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EN55022:1994 (Emissions)
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| CISPR 22 1993-12 Class A
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| FCC Part 15 Class A
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| EN 50082-1 (Immunity)
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| IEC 1000-4-2:1995 (IEC 801-2:1991)
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| IEC 1000-4-3:1995
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| IEC 1000-4-4:1995
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| Safety:
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EN 60950:1992/A1:1993
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| IEC 950:1991+A1:1992+A2:1993
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| UL 1950, cUL (CSA 950 accepted equivalent)
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| European CE compliance
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