523954 BLACK BOX, 523954 Datasheet - Page 2

• Manufacturer Part Number: 523954
• Description: DB9F-RJ45 ADAPTER SCA-MODADAPT
• Manufacturer: BLACK BOX

7/26/2010
#22457
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Multiplexor and line driver in one
compact unit.
Ideal for limited-distance applications.
Choose from 4- or 8-port models.
Easy to install, no option switches to set.
Transparent to speed and protocol.
Operates at distances up to 3000 ft. (914.4 m)
over 24 AWG twisted-pair wire.
Supports software (X-ON/X-OFF) flow control.
724-746-5500
blackbox.com
Use the existing 2-pair twisted-pair cable in your building to connect 4 or 8 PCs
to an async host up to 3000 feet (914.4 m) away.
OVERVIEW
Asynchronous Local RS-323
limited-distance line driver. Why buy a mux and a line driver separately
when you can get both in one convenient package? The async time-
division multiplexors (TDMs) support up to 4 or 8 channels. And the
line driver for twisted pair gives you point-to-point communications
over short distances (up to 3000 ft. [914.4 m]).
operates at speeds up to 38.4 kbps.
the TDM and line-driver combination offers a couple of advantages
for limited-distance applications:
• While Statistical Packet Multiplexing (SPM) is very efficient, sharing
• Leased-line modems are not used between devices in the same
maintained continuously with no operator control required. A Sync
Error indicator on the front of the unit alerts you if loss of sync occurs.
rates of the individual terminals, without requiring a clock source.
bandwidth dynamically, it’s also much more expensive than TDM.
If you have limited distances to carry data, the fixed bandwidth
used by TDMs gets you more for your money.
building or close to each other. To send data a short distance over
private, in-house, four-wire, point-to-point cable systems, you’d
typically use a line driver.
Local data communications are simple with the Black Box
The 4-Port Mux runs at speeds up to 64 kbps and the 8-Port Mux
Compared to statistical multiplexors and leased-line modems,
Synchronization between
What’s more, the Mux automatically adapts port speeds to the
Async Host
Mux. It comes with an integral four-wire
Asynchronous Local RS-232 Muxes
Async Local RS-232
Multiplexor, 4-Port
Serial Cable
(38887)
CAT5e Solid-Conductor
Backbone Cable (UTP)
(EYN795MS)
is
technically speaking
Time-division multiplexing (TDM).
into fixed-duration segments. Each segment or channel is
assigned to a user and is given its own time slot to access
the network. First, information from Channel A is transmitted,
then information from Channel B, and so on in a regular
sequence, continually cycling back to Channel A. Bandwidth
allocation is static: Each channel receives a fixed amount of
bandwidth, preset by the network administrator.
and is simple to implement, so it has typically been the first
multiplexing technique applied to any new high-speed service
at first offerings. TDM introduces very little signal delay, so
it’s well suited to transporting data, voice, and video traffic,
provided enough bandwidth is available.
channels onto one two-twisted-pair wire. Each data channel
can achieve speeds of up to 19.2 kbps.
TDM operates by dividing the available bandwidth
TDM is a relatively inexpensive multiplexing technique
The illustration above shows a mux merging eight data
Async Local RS-232
Multiplexor, 4-Port
Serial Cable
(38887)
BLACK BOX
Up to 4 PCs
®
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