PLT-22 Power Line Transceiver
Model 50090-03
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A reliable power line communications solution that can be
used worldwide
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Backward compatible
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replacement for Echelon鈥檚 PLT-21
transceiver
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Dual Carrier Frequency mode and Digital Signal
Processing
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Communicates over virtually any AC or DC power mains
and un-powered twisted pair
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Uses low cost coupling circuits and power supplies
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FCC, Industry Canada, Japan MPT, EIA 709.2, and
European CENELEC EN50065-1 compliant
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Supports optional PLA-21 external ampli鏗乪r
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Supports CENELEC A-band operation
Overview
The PLT-22 Power Line Transceiver provides a simple, cost-
effective method of adding L
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power line technology
to any control system. Network data are broadcast through the
power mains, eliminating the need for dedicated wiring and
greatly reducing installation costs. A backward compatible
replacement for Echelon鈥檚 popular PLT-21 Power Line
Transceiver, the PLT-22 transceiver includes several new features
to signi鏗乧antly improve communications reliability and lower
node cost.
Unsurpassed Performance
When the PLT-22 transceiver鈥檚 dual carrier frequency mode
is activated, PLT-22-based nodes are able to communicate
even when their primary frequency range (125kHz鈥?40kHz) is
blocked by noise. With dual carrier frequency mode, a PLT-22
transceiver begins each transmission by sending packets in the
primary frequency range 鈥?these packets may be received by
PLT-20, PLT-21, or PLT-22-based nodes. If impairments
prevent communication in this frequency range, the PLT-22 will
automatically switch to a secondary frequency range
(110kHz鈥?25kHz) in order to complete the transaction
with other PLT-22-based nodes.
The transceiver communicates at a raw bit rate of 5kbps.
With the CENELEC protocol disabled, the transceiver has
a maximum packet rate of 20 packets per second. With the
CENELEC protocol enabled, the transceiver has a maximum
packet rate of 18 packets per second. This high throughput
makes the transceiver well suited for residential, commercial,
and industrial automation applications.
The transceiver鈥檚 power ampli鏗乪r includes a selectable 3.5V
peak-to-peak (p-p) or 7V p-p mode for maximum
communication performance. The 1鈩?output impedance and
1A p-p current capability of the ampli鏗乪r allow it to drive
high output levels into low impedance circuits, while the highly
efficient design draws less total current than the previous trans-
ceivers. This increased output power improves signaling in all
applications and eliminates the expense of installing a phase
coupler in typical residential applications. The net cost savings
can be signi鏗乧ant for home automation applications.
A Global Product
The PLT-22 transceiver complies with FCC, Industry
Canada, Japan MPT, and European CENELEC EN50065-1
regulations for signaling in the 125kHz to 140kHz and 95kHz to
125kHz frequency bands. The transceiver implements the
CENELEC access protocol, which can be enabled or disabled by
the user. By incorporating the access protocol into the power line
transceiver, Echelon has eliminated the need for users to
independently develop the complex timing and access algorithms
mandated by the CENELEC EN50065-1 regulation.
The PLT-22 transceiver is also EIA 709.2 compliant.
Advanced Communications
Intermittent noise sources, impedance changes, and attenu-
ation make the power line a hostile signal path. The PLT-22
transceiver operates reliably in this harsh environment through a
novel Dual Carrier Frequency mode as well as custom digital
signal processing (DSP) which provides adaptive carrier and
data correlation, impulse noise cancellation, tone rejection,
and low overhead error correction. These innovations permit the
transceiver to operate reliably in the presence of consumer
electronics, power line intercoms, motor noise, electronic bal-
lasts, dimmers, and other typical sources of interference.
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