Echelon LONWORKS PLT-22 User Manual

LONWORKS®

PLT-22 Power Line Transceiver

User’s Guide

(110kHz – 140kHz Operation)

Version 1.2

@ ECHELON

C o r p o r a t i o n

078-0175-01C

®

Echelon, LON, LONWORKS, LonBuilder, NodeBuilder, LonManager, LonTalk,
L

ONMARK, Neuron, 3120, 3150, the LonUsers logo, the LONMARK logo, and

the Echelon logo are trademarks of Echelon registered in the United States
and other countries. LonPoint, LonSupport, and LonMaker are trademarks
of Echelon Corporation.

Other brand and product names are trademarks or registered
trademarks of their respective holders.

Neuron Chips, Power Line products, and other OEM Products were not
designed for use in equipment or systems which involve danger to
human health or safety or a risk of property damage, and Echelon
assumes no responsibility or liability for use of the Neuron Chips or Power
Line products in such applications.

Parts manufactured by vendors other than Echelon and referenced in
this document have been described for illustrative purposes only and
may not have been tested by Echelon. It is the responsibility of the
customer to determine the suitability of these parts for each
application.

ECHELON MAKES AND YOU RECEIVE NO WARRANTIES OR CONDITIONS,
EXPRESS, IMPLIED, STATUTORY OR IN ANY COMMUNICATION WITH YOU,
AND ECHELON SPECIFICALLY DISCLAIMS ANY IMPLIED WARRANTY OF
MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.

No part of this publication may be reproduced, stored in a retrieval
system, or transmitted, in any form or by any means, electronic,
mechanical, photocopying, recording, or otherwise, without the prior
written permission of Echelon Corporation.

Printed in the United States of America.
Copyright ©1996 - 2002 by Echelon Corporation.

Echelon Corporation
www.echelon.com

Contents

1 Introduction 1-1

Audience 1-6
Content 1-6
Related Documentation 1-6

2 Using the PLT-22 Transceiver 2-1

Mechanical Dimensions 2-2
PLT-22 Transceiver Pinout 2-3
PLT-22 Transceiver Electrical Specifications 2-4
External Components 2-6
Crystal 2-6
Power Supply Bypassing and Grounding 2-7
Band-in-Use (BIU) and Packet Detect (PKD) LED Connections 2-7
Neuron
Transmit Output Level 2-10
TXON Output Signal 2-10
Application Schematic: Neuron 3150® Chip 2-11
Application Schematic: Neuron 3120

3 PLT-22 Transceiver Programming 3-1

Dual Carrier Frequency Mode 3-2

CENELEC Access Protocol 3-3

Power Management 3-3
Standard Transceiver Types 3-4
LonBuilder
Channel Definitions

4 Coupling Circuits 4-1

Power Line Communications 4-2
Coupling Techniques 4-4
Power Line Coupling Basics 4-4
Power Line Coupling Details 4-8
Safety Issues 4-11
Safety Isolation Considerations 4-11
Ground Leakage Currents 4-13
Capacitor Charge Storage 4-13
Line Surge Protection 4-13
Fuse Selection 4-16
Recommended Coupling Circuit Schematics 4-16
Example 1: Line-to-Neutral, Non-Isolated Coupling 4-18
Example 2: Line-to-Neutral, Transformer-Isolated Coupling 4-20
Example 3: Line-to-Earth, Non-Isolated Coupling 4-22
Example 4: Line-to-Earth, Transformer-Isolated Coupling 4-24

®

Chip Connections 2-8

®

Chip 2-12

®

and NodeBuilder® PLT-22 Transceiver 3-6

LONWORKS PLT-22 Transceiver User’s Guide i

5 Power Supplies for the PLT-22 Transceiver

Introduction 5-2
Power Supply Design Considerations 5-2
Power Supply-Induced Attenuation 5-2
Power Supply Noise 5-3
Energy Storage Power Supplies 5-3
Energy Storage Capacitor-Input Power Supplies 5-5
Capacitor-Input Power Supply Schematic 5-7
Energy Storage Linear Supplies 5-8
Traditional Linear Power Supplies 5-9
Switching Power Supplies 5-9
Power Supply-Induced Attenuation 5-9
Noise at the Power Supply Input 5-12
Switching Power Supply Frequency Selection 5-12
Switching Power Supply Input Noise Masks 5-12
Switching Power Supply Output Noise Masks 5-17
Options 5-21
Pre-designed Switching Supplies 5-21
Off-the-Shelf Switching Supplies 5-22
Custom Switching Supplies 5-22

5-1

6 Design and Test for Electromagnetic Compatibility 6-1

EMI Design Issues 6-2
Designing Systems for EMC (Electromagnetic Compatibility) 6-2
ESD Design Issues 6-4
Designing Systems for ESD Immunity 6-4
Conducted Emissions Testing 6-6

7 Communication Performance Verification 7-1

Why Verify Communication Performance? 7-2
Verification Strategy 7-2
Power Line Test Isolator 7-3
Test Equipment 7-4
Good Citizen Verification 7-6
Unintentional Output Noise Verification 7-6
Excessive Loading Verification 7-7
Transmit Performance Verification 7-10
Receive Performance Verification 7-11
Packet Error Measurement with Nodeutil 7-11
Verification Procedure 7-12

8 References 8-1

Reference Documentation 8-2

Appendix A PLT-22 Transceiver Isolation Transformer A-1
Specifications

PLT-22 Transceiver Isolation Transformer Schematic A-2
PLT-22 Transceiver Isolation Transformer Electrical A-2
Specifications
PLT-22 Transceiver Isolation Transformer Vendors A-3

ii Echelon

Appendix B PLT-22 Transceiver-Based Node Checklist B-1

PLT-22 Transceiver-Based Node Checklist B-2
PLT-22 Transceiver and Neuron Chip Connections B-2
PLT-22 Transceiver Programming B-4
PLT-22 Transceiver Coupling Circuit General B-4
PLT-22 Transceiver Coupling Circuit Components Key B-5
Specifications
PLT-22 Transceiver Power Supply - General B-6
PLT-22 Transceiver Power Supply - Switching Type B-6
EMI & ESD Design B-7
Product Qualification - EMC B-8
Product Qualification - Electromagnetic Immunity and B-8
Communication Performance

Appendix C External Power Supplies with Integrated

Coupling Circuits C-1

Vendors for External Power Supplies w/ Integrated Coupling Circuits C-2

LONWORKS PLT-22 Transceiver User’s Guide iii

iv Echelon

1

Introduction

The PLT-22 Power Line Transceiver provides a simple, cost-effective
method of adding LONWORKS® 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 replacement for Echelon's popular PLT-21 Power
Line Transceiver, the PLT-22 transceiver also includes several new
features to significantly improve communications reliability and lower
node cost.

LONWORKS PLT-22 Transceiver User’s Guide 1-1

Intermittent noise sources, impedance changes, and attenuation make the power line
a hostile signal path. The PLT-22 transceiver operates reliably in this harsh
environment through a novel dual carrier frequency capability as well as custom
digital signal processing 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 ballasts, dimmers, and
other typical sources of interference.

Each PLT-22 transceiver operates as a backward compatible replacement for the
PLT-20 and PLT-21 transceivers when used with previous versions of configuration
parameters. In this mode, all transmissions can be received by any PLT-20, PLT-21,
or PLT-22 transceiver.

When used with new transceiver configuration parameters, the dual carrier
frequency mode of the PLT-22 transceiver is activated. In this mode, PLT-22 based­nodes are able to communicate even when the primary frequency range (125kHz ­140kHz) is blocked by noise. With dual frequency mode, a PLT-22 transceiver begins
each transaction by sending backward compatible packets. If impairments prevent
communication in this frequency range, the PLT-22 node will automatically switch
carrier frequencies in order to complete the transaction with other PLT-22 based
nodes.

The PLT-22 transceiver complies with FCC, Industry Canada, Japan MPT, and
European CENELEC EN 50065-1

1

regulations for signaling in the 125kHz-to­140kHz and 95kHz-to-125 kHz 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 EN 50065-1 regulation. The PLT-22
transceiver also is compliant with the Electronic Industries Association Standard
EIA-709.2.

The transceiver's power amplifier includes a selectable 3.5V peak-to-peak (p-p) or 7V
p-p mode for maximum communication performance. The 1Ω output impedance and
1A p-p current capability of the amplifier allow it to drive high output levels into low
impedance circuits, while the highly efficient design draws less total current than
previous transceivers.

The PLT-22 transceiver is powered by user-supplied +8.5 to +16VDC and +5VDC
power supplies. The wide supply range is a key benefit when designing inexpensive
power supplies. If a battery-backed power supply is used, the transceiver will
continue signaling even during a power failure on the power mains.

The PLT-22 transceiver incorporates a power management feature that constantly
monitors the status of the node's power supply. If during transmission the power
supply voltage falls to a level that is insufficient to ensure reliable signaling, the
transceiver tells the Neuron Chip to stop transmitting until the power supply voltage
rises to an acceptable level. This allows the use of a power supply with 1/3 the
current capacity otherwise required (100mA versus 300mA). The net result is a
reduction in the size, cost, and thermal dissipation of the power supply. Power
management is especially useful for high volume, low cost consumer products such as
electrical switches, outlets, and dimmers.

1-2 Introduction

The PLT-22 transceiver uses a low-cost external coupling circuit and can
communicate over virtually any AC or DC power mains, as well as unpowered
twisted pair. The PLT-22 transceiver can use all of the same coupling circuits as the
PLT-21 transceiver.

The PLT-22 transceiver is supplied as a miniature uncoated Single In-Line Package
(SIP) which can be mounted on or inside an OEM product, directly adjacent to the
Neuron Chip with which it is used. The PLT-22 transceiver maintains drop-in pin
compatibility with the PLT-20 and PLT-21 transceivers while at the same time
providing smaller package dimensions to more easily fit into tight enclosures. When
connected to an external crystal, the transceiver can supply either a 1.25, 2.5, 5, or
10MHz clock signal for the Neuron Chip, eliminating the need for a separate Neuron
Chip crystal.

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
throughput of 18 packets per second. This high throughput makes the transceiver
well suited for residential, commercial, and industrial automation applications.

For commercial and industrial applications in high rises, manufacturing plants,
utility substations, and other large facilities, the PLT-22 transceiver can be used
with Echelon's PLA-21 Power Line Amplifier. Capable of transmitting a 10Vp-p
signal with 2Ap-p current drive, the PLA-21 amplifier is ideal for driving multiple
phase coupling circuits, high attentuation power circuits, and very low impedance
loads near circuit breaker panels and distribution transformers.

This guide describes the use of the PLT-22 transceiver in the 110kHz to 140kHz
frequency range. The PLT-22 transceiver also supports communication in the
CENELEC utility band (European A-band from 70 to 95kHz) when the transceiver is
used with a different external crystal and modified coupling circuit. For CENELEC
utility applications, refer to the companion user’s guide, Using the L

22 Power Line Transceiver in European Utility Applications.

ONWORKS PLT-

LONWORKS PLT-22 Transceiver User’s Guide 1-3

GND

CKOUT

CKSEL1

CKSEL0

XIN

XOUT

PKD

BIU

RXIN

RXCOMP

TXLVL

TXOUT

CP0

CP1

CP2

CP4

~RESET

GND

GND

V

A

V

DD5

RX

FRONT

END

A/D

TX
AMP/
FLTR

DSP

D/A

Figure 1.1 PLT-22 Transceiver Block Diagram

The compact PLT-22 transceiver must be mounted using hand or wave soldering and
requires only the addition of a Neuron 3120

®

Chip or Neuron 3150® Chip, crystal, power
line coupling network, power supply, and application electronics to build a complete node
(figure 1.2).

User's
Application
Electronics

1-4 Introduction

11

Neuron

Chip

V

DD5

Transceiver

V

A

PLT-22

Coupling

Circuit

Power Supply

Figure 1.2 Typical PLT-22 Transceiver-Based Node

Power
Mains

The PLT-22 transceiver meets the regulations for AC mains signaling of the FCC
(Federal Communication Commission), Industry Canada (formerly DOC), CENELEC
(European Committee for Electrotechnical Standardization), and Japanese MPT
(Ministry of Post and Telecommunications).

Under FCC Section 15.107 "Limits for carrier current systems," as well as Industry
Canada guidelines, communication frequencies are allocated as shown in figure 1.3.
To protect aircraft radio navigation systems operating between 190kHz and 525kHz,

restrictions on power line communication above 185kHz are being considered
PLT-22 transceiver avoids interfering with these systems by signaling in the
frequency range of 110kHz to 140kHz.

PLT-22
Transmit
Signals

General
Use

Restrictions Under

Consideration

Restricted

7

. The

100kHz 200kHz 300kHz 400kHz 500kHz 600kHz 700kHz

Figure 1.3 FCC and Industry Canada Frequency Allocation

Under CENELEC EN 50065-1 “Signaling on low-voltage electrical installations in the
frequency range 3kHz to 148.5kHz” Part 1 “General requirements, frequency bands
and electromagnetic disturbances," communication frequencies are allocated as shown
in figure 1.4. When used with a 10MHz crystal, the PLT-22 transceiver signals in
CENELEC C and B bands and implements the access protocol as specified in
CENELEC EN 50065-1 (see CENELEC Access Protocol section in Chapter 3 for more
information). For operation in the CENELEC A-band, refer to Using the L

PLT-22 Power Line Transceiver in European Utility Applications.

ONWORKS

LONWORKS PLT-22 Transceiver User’s Guide 1-5

Band Designations:

PLT-22 with

70 - 95kHz Operation

"A"

{

PLT-22 with

110 - 140kHz Operation

{

"B"

"C" "D"

Electricity Suppliers

Audience

This document is intended for designers of products using the PLT-22 Power Line
Transceiver.

Content

This manual provides detailed operating instructions for the PLT-22 transceiver.

Electricity Suppliers

and Their Licensees

PLT-22
Secondary
Signal

20kHz 40kHz 60kHz 80kHz 100kHz 120kHz 140kHz 160kHz

Figure 1.4 CENELEC Frequency Allocation

PLT-22
Primary
Signal

No Protocol

Consumer Use

PLT-22

PLT-22
Secondary

Secondary
Signal

Signal

Consumer Use

PLT-22
Primary
Signal

No Protocol

With Protocol

Restricted

Consumer Use

Related Documentation

The following documents are suggested reading:

PLT-22

PLCA-22 Power Line Communication Analyzer User’s Guide (078-0147-01)

PLA-21 Power Line Amplifier Specification and User’s Guide (078-0161-01)

Centralized Commercial Building Applications with the L
Transceiver (005-0056-01)

Demand Side Management with the L

(005-0070-01)

Using the L
Applications (078-0180-01)

1-6 Introduction

Power Line Transceiver data sheet (003-0250-01)

ONWORKS PLT-22 Power Line Transceiver in European Utility

ONWORKS PLT-21 Power Line

ONWORKS Power Line Transceivers

LONWORKS Custom Node Development (005-0024-01)

L

ONMARK

L

ONMARK Application Layer Interoperability Guidelines (078-0120-01)

®

Layers 1-6 Interoperability Guidelines (078-0014-01)

Neuron Chip Data Book as published by Motorola and Toshiba

LONWORKS PLT-22 Transceiver User’s Guide 1-7

1-8 Introduction

2

Using the PLT-22 Transceiver

This chapter describes the mechanical and electrical characteristics of
the PLT-22 transceiver along with the interface to a Neuron Chip and
external circuitry requirements. Typical application schematics are
included.

LONWORKS PLT-22 Transceiver User’s Guide 2-1

Mechanical Dimensions

Figure 2.1 presents the mechanical dimensions of the PLT-22 transceiver.

The PLT-22 is produced as an uncoated SIP (in contrast to the coated PLT-20 and
PLT-21 transceivers).

Figure 2.1 PLT-22 Transceiver Dimensions

Note: If a socket is required for prototype purposes, a Mill-Max #317-93-121-41-005
connector may be used. For more information, contact:

Mill-Max Manufacturing Corporation
190 Pine Hollow Road
Oyster Bay, New York, 11771
Telephone: [phone]
Fax: [phone]
Internet: http://www.mill-max.com

2-2 Using the PLT-22 Transceiver

PLT-22 Transceiver Pinout

Table 2.1 lists the functions of the PLT-22 transceiver pins.

Table 2.1

Pin # Pin Name Function

1 RXCOMP Connection to receive compensation component
2 RXIN Receive signal input from line coupling circuit
3 GND Ground
4 CP4 Frame clock synchronization from Neuron Chip (FCLK)
5 CP2 Bit clock synchronization from Neuron Chip (BCLK)
6 CP1 Transmit data and configuration from Neuron Chip (TXD)
7 CP0 Receive data and status to Neuron Chip (RXD)
8 GND Ground
9 V

10 CKOUT Buffered CMOS clock output: 10, 5, 2.5 or 1.25 MHz
11 CKSEL0 Selects frequency of CKOUT—see table 2.4
12 CKSEL1/TXON Selects frequency of CKOUT—see table 2.4 / TXON (supports

13 ~RESET Reset input from Neuron Chip
14 BIU CENELEC Band-In-Use indication output
15 PKD Packet detect indication output
16 TXOUT Transmit signal output to line coupling circuit
17 GND Ground
18 XIN 10MHz oscillator input
19 XOUT 10MHz oscillator output
20 VA Analog power supply input

21 TXLVL Transmit level selection input

+5VDC power supply input

DD5

PLA-21 Power Line Amplifier)

PLT-22 Transceiver Pinout

LONWORKS PLT-22 Transceiver User’s Guide 2-3

PLT-22 Transceiver Electrical Specifications

Table 2.2 lists the electrical specifications of the PLT-22 transceiver when used in
the 110kHz – 140kHz frequency range. All specifications apply over the full
operating temperature and supply voltage ranges unless otherwise indicated.

Table 2.2

Parameter Min Typ Max Units

Operating temperature range1
V

input supply voltage 4.75 5 5.25 Volts

DD5

VA input supply voltage

TXLVL = open 8.5 9.7 16 Volts
TXLVL = GND2

I

input supply current (not including PKD and BIU LED Current)

DD5

receive 16 23 mA
transmit 13 18 mA
IA input supply current

receive 4 6 mA
transmit 130 250 mA
TXOUT signal level: TXLVL=open, into 50Ω load 3.6 Volts p-p
TXOUT signal level: TXLVL=GND, into 50Ω load 7 Volts p-p
Output current limit 1.0 Amps p-p
Output impedance, in-band (transmit) 0.9 1.1 Ohms
Input impedance, in-band (receive) 500 Ohms
PKD output source current @ V

BIU output source current @ V
Power management, lower threshold 7.2 7.9 8.5 Volts

Power management, upper threshold 11.1 12.0 12.9 Volts

PLT-22 Transceiver Electrical Specifications

-40 +85 ° C

11.4 12.0 16 Volts

-0.6 V 8 mA

DD5

-0.6 V 8 mA

DD5

Notes:

1. Maximum operating temperature is a function of VA supply voltage and the maximum
transmission duty cycle for the node. A maximum operating temperature of 85°C is

specified for a V

A

the maximum achievable with LONMARK interoperable transceiver parameters and
messages of ≤34 Bytes. For other cases see figure 2.2.

2. While operating in the 7V p-p mode (TXLVL = GND), the V

11.4V under conditions of typical line voltage, room temperature, and typical current drain
(including the PLT-22 transceiver’s typical IA transmit current of 130mA). This condition

ensures adequate transmit amplifier headroom to drive the full 7Vp-p signal

2-4 Using the PLT-22 Transceiver

supply ≤12.6V and a maximum transmit duty cycle of 65%, which is

supply must not drop below

A

onto typical lines. Under worst case conditions, the minimum VA supply voltage may be

relaxed if the following additional condition is met. With worst case power supply
loading (including PLT-22 I

= 250mA), worst case component tolerances, worst case line

A

voltage, and worst case temperature, VA must remain greater than or equal to 9.0V.
This condition ensures adequate transmit amplifier headroom when driving low

impedance power lines.

When using an energy storage type power supply refer to Chapter 5 for additional timing
requirements on the above conditions.

85
80

75

VA Max =12.6V

70

65

60

55

50

VA Max =16V

45

40
35

Maximum possible transmit duty cycle
using LONMARK interoperable

30

Maximum Operating Temperature (°C)

25

transceiver parameters and messages
Š34 bytes

10%

20%

30%

40%

50% 60%

70%

80% 90%

Transmit Duty Cycle

Figure 2.2 PLT-22 Transceiver Maximum Operating Temperature vs. Transmit Duty Cycle

100%

LONWORKS PLT-22 Transceiver User’s Guide 2-5

External Components

Crystal

The PLT-22 transceiver requires the connection of an external 10.0000MHz crystal.
The crystal connects directly to two pins of the PLT-22 transceiver, with no other
oscillator components being required external to the transceiver. The crystal should
be mounted as close as possible to the transceiver to minimize parasitic effects. The
traces connecting the crystal to the transceiver preferably should be less than 10mm
(0.4") in length, and under no circumstances can they exceed 20mm (0.8") in length.

In addition to the nominal frequency specification of 10.0000MHz, the crystal should
be a parallel resonant type with a load rating of 13 to 20pF (series resonant crystals
should not be used). The frequency accuracy of the oscillator must be held to ±200
ppm over the full temperature range of operation. The PLT-22 oscillator design is
centered for the use of a crystal with a 16pF load rating. If a 13pF crystal is used,
the nominal frequency of oscillation will be 30 to 55ppm low, leaving 145ppm
available for crystal accuracy, temperature, and aging. If a 20pF crystal is used, the
nominal frequency will be 50 to 85ppm high, leaving 115 ppm for accuracy,
temperature, and aging.

While the PLT-22 transceiver design is centered around the use of a crystal whose
load capacitance rating is 16pF, it is possible to recenter the design for a crystal
whose load capacitance rating is higher than 16pF. The PLT-22 transceiver
effectively contains two 32pF capacitors, one from XIN to ground and one from
XOUT to ground. Note that the series combination of the two capacitors equals the
load capacitance of the recommended crystal. Recentering the design for the use of a
crystal with a higher load capacitance specification requires the addition of two
external capacitors whose series equivalent capacitance is equal to the load
capacitance specification of the crystal less 16pF. For instance, to use a crystal with
a load capacitance specification of 30pF, the operating frequency can be centered by
adding two 27pF capacitors, one from XIN to ground and one from XOUT to ground.

If a 10.0000MHz ±200ppm 0-5V clock signal is already available as part of the node
hardware then it may be used as a clock source for the PLT-22 transceiver by
connecting it to Pin 18 (XIN) of the transceiver. In this instance pin 19 (XOUT) of
the PLT-22 should be left unconnected. With this option, appropriate high speed
clock distribution techniques must be strictly followed in order to ensure that a clean
clock signal is present at the XIN pin of the PLT-22 transceiver.

Oscillator frequency accuracy should be checked during the design verification phase
of every PLT-22 based product. Frequency accuracy should be measured by using a
frequency counter connected to the CKOUT pin to compare the frequency of that pin
to the selected value (i.e., 10, 5, 2.5, or 1.25MHz). Be sure that no instruments or
extra cabling are connected to either the XIN or XOUT pins of the PLT-22 since even
2pF of extra load on either pin will significantly change the oscillator frequency.

2-6 Using the PLT-22 Transceiver

Power Supply Bypassing and Grounding

The PLT-22 transceiver requires the connection of external bypass capacitors. The
bypass capacitors should be placed as close as possible to the PLT-22 transceiver,
and low-impedance ground and supply traces should be used between the PLT-22
transceiver and the bypass capacitors. In addition to the bypass capacitors specified

for the Neuron Chip (see Neuron Chip Data Book
the V

and VA bypass capacitors are, as follows:

DD5

2,3,18

), the recommended values of

: None required if the V

V

DD5

supply at the PLT-22 transceiver pin 9

DD5

meets the noise masks described in Chapter 5. It is recommended
that PCB designs initially incorporate a 10µF 10V tantalum capacitor
and a 0.1µF ceramic capacitor on the V

suppy. These capacitors

DD5

can be eliminated if the design meets the noise masks in Chapter 5
and passes the receive performance tests described in Chapter 7
without the capacitors installed.

VA: 120µF (minimum) 16V, low-ESR (<0.3Ω @ 100kHz), high-frequency

aluminum electrolytic capacitor. Low ESR is required in order to
minimize VA ripple voltage when the transceiver drives low

impedance loads, drawing several hundred milli-Amperes of peak-to­peak ripple current. Note that the VA bypass capacitor is an integral

part of the mains surge protection circuitry described in Chapter 4.
In particular, the coupling circuits of Chapter 4 require the use of an
aluminum electrolytic type capacitor with a voltage rating of 16V.
Higher or lower voltage ratings will likely result in surge immunity
which is significantly below the verified levels documented in
Chapter 4.

The PLT-22 transceiver provides three ground pins. For proper operation,
all three pins must be connected to ground with low-impedance traces, or
to a ground plane between the transceiver and the Neuron Chip.

Band-In-Use (BIU) and Packet Detect (PKD) LED Connections

The PLT-22 transceiver supplies two output signals, PKD and BIU, that are
intended to drive low-current light-emitting diodes (LEDs). Both signals are active­high and must be connected to separate LEDs, with series current-limiting resistors
added between the LEDs and ground.

A Band-In-Use detector, as defined under CENELEC EN 50065-1, must be active
whenever a signal that exceeds 80dBµVrms anywhere in the frequency range

131.5kHz to 133.5kHz is present for at least 4ms. The Band-In-Use detector is
defined by CENELEC EN 50065-1 as part of the CENELEC access protocol. The
PLT-22 transceiver incorporates the CENELEC access protocol, and the PLT-22
transceiver may be programmed to enable or disable its operation. (See CENELEC
Access Protocol in Chapter 3 for more information.) When the PLT-22 transceiver is
programmed such that the CENELEC access protocol is enabled, the BIU signal is
active high whenever the CENELEC-defined conditions for Band-In-Use are met.
When the transceiver is programmed such that the CENELEC access protocol is

LONWORKS PLT-22 Transceiver User’s Guide 2-7

disabled, the threshold for the BIU signal is increased to 84dBµVrms to reduce the
possibility that power mains noise activates the BIU indicator. When the CENELEC
access protocol is disabled, an active BIU signal does not prevent the PLT-22
transceiver from transmitting. Connecting the BIU signal to an LED is most useful
when the CENELEC access protocol is enabled, since in this case the BIU signal
indicates when the PLT-22 transceiver's transmissions are restricted.

The PKD signal is active whenever a valid LonTalk
PLT-22 transceiver. The receive sensitivity of the transceiver is considerably greater
than that of the BIU indicator. The PKD signal will go active when the PLT-22
transceiver receives packets whose signal level is as small as 36dBµVrms. Thus it is
not uncommon for the PKD indicator to signal that a packet is present without the
BIU indicator turning on; this occurs in cases where the received packet signal
strength is less than the BIU threshold.

Both the BIU and PKD signals are driven directly by the PLT-22 transceiver’s DSP
processor. ESD protection diodes should be connected to these pins in applications
where the BIU and PKD signals drive LEDs that could be subject to ESD exceeding
2kV. In applications where the LEDs are surrounded by a metallic ground plane,
such as a hole in a grounded metal enclosure, the ESD diodes may not be necessary.
However, if a plastic or metal enclosure without a good ground connection is used,
then ESD diodes are needed to prevent damage to the PLT-22 transceiver. ESD
protection diodes include industry part types 1N4148 (thru-hole) and BAV99 (SMT).
Typical sources for BAV99 diodes include Motorola (BAV99LT1), National (BAV99),
and Diodes, Inc. (BAV99).

Neuron Chip Connections

The link between the Neuron Chip and the PLT-22 transceiver makes use of the
Neuron Chip's special-purpose mode interface. This interface requires that the CP
and ~RESET lines of the two devices be interconnected as shown in table 2.3.

Table 2.3 Neuron Chip and PLT-22 Transceiver Interconnections

®

packet is being received by the

The Neuron Chip and PLT-22 transceiver should be placed adjacent to one another
on the same printed circuit board. The length of the ~RESET and CP lines should be
kept to an absolute minimum and in no case should exceed 50mm (2"). In addition,

2-8 Using the PLT-22 Transceiver

Neuron Chip Pin PLT-22 Pin

CP0 7
CP1 6
CP2 5
CP3 Do not connect
CP4 4

~Reset 13

CLK1 10

the ground traces and V

trace between the PLT-22 transceiver and the Neuron

DD5

Chip should have impedances as low as possible.

The PLT-22 transceiver's CKOUT pin provides a clock suitable for driving the
Neuron Chip CLK1 at 1.25MHz, 2.5MHz, 5MHz, or 10MHz. The frequency of the
CKOUT pin (Neuron Chip CLK1 input) is selected by two pins, CKSEL0 and
CKSEL1/TXON, as shown in table 2.4. The Neuron Chip CLK2 pin is not connected.
The length of the CKOUT line should be kept to an absolute minimum and should in
no case exceed 50mm (2").

Table 2.4 PLT-22 Transceiver Output Clock Frequency Settings

CKSEL1/TXON CKSEL0 CKOUT FREQ. (MHz)

≥ 4.7k to GND (or open) GND 1.25
≥ 4.7k to GND (or open) VDD 2.5

4.7k to VDD V

5

DD

4.7k to VDD GND 10

The CKSEL1/TXON pin must never be connected directly to a supply rail. The
CKSEL1/TXON pin will draw large currents and potentially damage the
PLT-22 transceiver if it is connected directly to a supply rail. The CKSEL0

pin may be tied directly to V

or GND.

DD5

!

Note that when the PLT-22 transceiver is operated in its new dual
frequency mode (as described in Chapter 3, PLT-22 Transceiver
Programming) the Neuron Chip clock must be set to be 2.5MHz or higher.

The PLT-22 transceiver ~RESET pin is designed to connect directly to the Neuron

2,3,18

Chip ~RESET pin. The Neuron Chip Data Book

provides information on the

Neuron Chip’s external reset circuitry. Depending on the particular Neuron

Chip version used, a Low Voltage Indicator (LVI) circuit such as the
Motorola MC33064 or Dallas 1233 may be necessary to supply a reset signal
to both the Neuron Chip and the PLT-22 transceiver. All of the application

circuits shown in this documentation include an LVI chip. Consult your Neuron
Chip manufacturer for the latest reset circuit requirements. Whether an LVI chip or
a simpler discrete circuit is required, the ~RESET pin of the PLT-22 should always
be tied directly to the ~RESET pin of the Neuron Chip. To minimize the effect of
ESD discharges on the Neuron Chip ~RESET pin, use two external 56pF ceramic
capacitors, one tied between ~RESET and V

, the other between ~RESET and

DD5

GND. The capacitors should be placed as close as possible to the Neuron
Chip ~RESET pin. Note that the PLT-22 transceiver already incorporates two
56pF capacitors on the ~RESET line internal to the transceiver. These internal
capacitors should be taken into account when calculating the total allowable
capacitive load on the Neuron Chip ~RESET pin, as specified in the Neuron Chip

Data Book

2,3,18

.

LONWORKS PLT-22 Transceiver User’s Guide 2-9

Transmit Output Level

The TXLVL input pin on the PLT-22 transceiver determines the output voltage of the
transmit signal. When the TXLVL pin is left floating, the transceiver's open-circuit
output voltage is 3.5V p-p. When the TXLVL pin is grounded, the open-circuit
output voltage is increased by 6dB to 7Vp-p. The appropriate setting for TXLVL is
summarized in table 2.5.

TXLVL OUTPUT

grounded 7Vp-p Preferred mode of operation. Use for FCC,

open 3.5Vp-p Use for CENELEC EN50065-1 class 116

Table 2.5 TXLVL Setting

APPLICATION

VOLTAGE

Industry Canada, CENELEC class 134, Japan
MPT, and all dedicated wiring applications.

applications

TXON Output Signal

The PLT-22 transceiver provides an output signal suitable for controlling a PLA-21
Power Line Amplifier via the CKSEL1/TXON pin. The CKSEL1/TXON pin functions
as an input during the period in which the ~RESET pin of the PLT-22 transceiver is
held active (low). During the reset active period the logical states of the
CKSEL1/TXON and CKSEL0 pins are sampled and stored by the PLT-22
transceiver. The stored state is used to determine the frequency of CKOUT, as
described in table 2.4. After RESET becomes inactive (high) CKSEL1/TXON changes
to an output (CKSEL0 remains an input, but its state is ignored). The output, called
TXON, is a buffered version of the internal signal used to control the transceiver's
output amplifier. The TXON signal output is active high when the PLT-22
transceiver transmits packets.

The TXON signal is typically used to provide tri-state control of an external booster
amplifier, such as the PLA-21 Power Line Amplifier model 53001-01. For more
details see the PLA-21 Power Line Amplifier Specification and User's Guide.

2-10 Using the PLT-22 Transceiver

Optional power supply filter

(not required for linear

power supplies) See

chapter 5

See chapter 5

Power Supply

LINE

120 µF, 16VDC

Aluminum Electrolytic.

Close to PLT-22 VA pin.

See coupling circuits in

chapter 4

+VA

5

TANT,

Close to PLT-22

VDD pin

5 10 µF,10VDC

bypass

capacitors:

0.1 µF, 25VDC

6 places

VDD

1

2

RXIN

RXCOMP

EARTH

NEUTRAL

See chapter 4

Coupling Circuit

+5V

111215

5

VDD

CKSEL0

Optional Packet Detect and

Band-In-Use Indicators

470ž

470ž

* Refer to the Neuron 3150 Chip External

Memory Interface application note for

memory connection information.

GND for 7V p-p

transmit level;

Open for 3.5V p-p

4.7kž

14

16

BIU

PKD

TXOUT

CKSEL1

transmit level

21

TXLVL

3

A

+5V

+V

D0D1D2D3D4D5D6

13141518192021

O0O1O2O3O4O5O6

A0A1A2A3A4A5A6A7A8A9A10

98765

11

10

A0A1A2A3A4A5A6A7A8A9A10

D7

22

O7

4

292824

11217

26

NCNCNC

PROM

27C256

A11

A12

273303123

A11

A12

A13

2

+5V

PLT-22

~RESET

GND

CP4

CP2

+5V

+5V

32

16

NC

VDD

A13

A14

CE~

OE~

2

25

A14

A15

D7
D6
D5

D4

GND

D3
D2

+5V

D1

D0

VPP

+5V

33
34
35
36

37
38
39
40

41
42
43
44

open

45
46

A15

47
48

CP1

567

4

3

open

323130292827262524232221201918

CP4

CP3

CP2

CP1

D7

D6
D5

D4
D3
D2

VSS
VDD
VDD

D1
D0

VDD

R/~W

~E

A15

NC

NC

A14

A13

A12

495051525354555657585960616263

A11

A12

A13

A14

CKOUT

CP0

GND

8

10913

+5V

+5V

open

+5V

open

NC

CP0

VDD

VDD

VSS

CLK1

CLK2

VDD

VSS

Neuron 3150 Chip

A11

A10A9A8A7A6A5A4A3A2A1A0

GND

XIN18XOUT

17

19

10MHz

open

17

NC

VSS

IO10

~SERVICE

IO9
IO8

IO7

IO6
IO5
IO4
VSS
VSS

VDD
~RESET

IO3
IO2
IO1

IO0

NC

64

A0A1A2A3A4A5A6A7A8A9A10

Keep these lines short.

VA

20

+VA

16
15
14
13

12
11
10
9

8
7

+5V

6
5

4
3
2
1

MC33064D

1

56pF

+5V

56pF

Figure 2.2 Neuron 3150 Chip Application Schematic

Locate close to Neuron Chip

To User's Application Electronics

LONWORKS PLT-22 Transceiver User’s Guide 2-11

Optional power supply filter

(not required for linear

power supplies) See

Chapter 5

See Chapter 5

Power Supply

LINE

NEUTRAL

See Chapter 4

Coupling Circuit

1

2

RXIN

RXCOMP

EARTH

+5V

5

VDD

4.7kž

14

111215

BIU

CKSEL1

CKSEL0

Optional Packet Detect and

Band-In-Use Indicators

470ž

470ž

GND for 7V p-p

transmit level;

Open for 3.5V p-p

transmit level

PKD

16

TXOUT

21

TXLVL

CP2

567

open

CP3

D
D
V

+5V

CP1

CP1

VSS

CP0

CP0

CLK2

open

GND

8

+5V

17

VDD

CLK1

PLT-22

CKOUT

10913

CP2

VSS

~RESET

XIN18XOUT

10MHz

VA

19

20

VA

GND

17

Figure 2.3 Neuron 3120 Chip Application Schematic

3

2

+5V

MC33064D

1

56pF

+5V

56pF

Keep these lines short.

Locate close to Neuron Chip

A

V

+5V

CP4

GND

3

4

120 µF, 16VDC

Aluminum Electrolytic.

Close to PLT-22 VA

pin. See coupling

10 µF, 10VDC, TANT

VA

Close to PLT-22

VDD pin

+5V

5

circuits in chapter 4

5

VDD bypass

capacitors:

0.1 µF, 25VDC,

5 places

To User's
Application
Electronics

IO6

IO7

IO2

IO3

+5V

VDD

IO8

IO9

IO10

Neuron

3120 Chip

~SERVICE

IO0

IO1

VSS

Electronics
Application

To User's

CP4

VSS

D
D
V

VSS

10111213141516

+5V

+5V

323130292827262524232221201918

IO5

VSS

VDD

~RESET

VDD

IO4

123456789

+5V

2-12 Using the PLT-22 Transceiver

3

PLT-22 Transceiver Programming

Certain parameters of the PLT-22 transceiver are programmed by the
user. This chapter presents a list of these parameters and their
values, plus a description of how they are programmed via the

LonBuilder
Development Tool.

®

Developer’s Workbench and the NodeBuilder™

LONWORKS PLT-22 Transceiver User’s Guide 3-1

Dual Carrier Frequency Mode

Each PLT-22 transceiver incorporates a new dual carrier frequency capability which
allows it to communicate with other PLT-22-based nodes, even if noise is blocking its
primary communication frequency range. If impairments prevent communication in
this range, a PLT-22-based node can automatically switch to a secondary carrier
frequency to complete a transaction with other PLT-22-based nodes.

With dual carrier frequency mode enabled, the last two retries of acknowledged
service messages are sent using the secondary carrier frequency. Thus when
acknowledged service is used with three retries (four total tries), the first two tries
are sent using the 132kHz primary carrier frequency. If the last two tries are needed
to complete the transaction, they are sent (and acknowledged) using the 115kHz
secondary carrier frequency. A minimum of two retries must be used if the PLT-22
transceiver is to be able to use both carrier frequency choices. For optimum
reliability and efficiency, Echelon recommends the use of three retries when using
acknowledged service messaging with the PLT-22 transceiver.

When unacknowledged repeat message service is used, the PLT-22 transceiver
leverages the reliability of both carrier frequencies by alternating between them. In
this case an unacknowledged repeat message with three repeats results in the first
and third packets being sent using the 132kHz primary carrier frequency, while the
second and fourth packets are sent using the 115kHz secondary carrier frequency. A
minimum of one repeat must be used for the PLT-22 transceiver to use both carrier
frequency choices.

Every PLT-22 transmission at the 115kHz secondary carrier frequency is
accompanied by a simultaneous 132kHz “pilot” signal which older PLT-20 and PLT­21-based nodes can use to recognize that the channel is busy. This pilot signal
prevents PLT-20- or PLT-21-based nodes (which cannot detect the 115kHz secondary
carrier frequency) from transmitting at the same time that a PLT-22 is transmitting
on its 115kHz secondary carrier frequency.

The user can configure a PLT-22-based node to operate with the dual carrier
frequency mode either enabled or disabled. When a PLT-22-based node is operated
with dual carrier frequency mode enabled, it will operate as described above. When
a PLT-22-based node is operated with dual carrier mode disabled, it will only
transmit using its 132kHz primary carrier frequency. Note that the selection of dual
frequency mode on a PLT-22-based node only affects its transmission characteristics.
Each PLT-22 transceiver is always able to automatically detect and properly receive
packets at either frequency, regardless of whether or not dual frequency
transmission is enabled. Activation of dual carrier frequency mode is controlled by
the revision level of standard transceiver parameters, as described later in this
chapter.

3-2 PLT-22 Transceiver Programming

CENELEC Access Protocol

To allow multiple power line signaling devices from different manufacturers to
operate on a common AC mains circuit, the CENELEC standard EN 50065-1
specifies an access protocol for the C-band (125kHz to 140kHz). The frequency

132.5kHz is designated as the primary band-in-use frequency that indicates when a
transmission is in progress.

Every power line signaling device must both monitor the 132.5kHz band-in-use
frequency and be able to detect the presence of a signal of at least 80dBµVrms
anywhere in the range from 131.5kHz to 133.5kHz which has a duration greater
than or equal to 4 milliseconds. A power line signaling device is permitted to
transmit if the band-in-use detector shows the band to have been free for at least 85
milliseconds. Each device must randomly choose an interval for transmission, and at
least seven evenly distributed intervals must be available for selection. A group of
power line signaling devices is allowed to transmit continually for a period less than
or equal to one second, after which it must cease transmitting for at least 125
milliseconds.

The PLT-22 transceiver incorporates the CENELEC access protocol and the user can
enable or disable the CENELEC access protocol at the time of channel definition.
When enabled, the PLT-22 transceiver enforces the CENELEC access protocol while
still maintaining the benefits of the LonTalk protocol. When the CENELEC access
protocol is enabled, overall network throughput is reduced by 11%.

Power Management

The PLT-22 transceiver incorporates a power management feature that supports the
design of very low cost power supplies in low cost consumer applications such as
networked light dimmers, switches, and household appliances. This class of
consumer applications have low transmit duty cycle operation requirements. These
low cost power supplies take advantage of a number of PLT-22 features: the low
receive current requirements of the PLT-22 transceiver; the 9:1 difference between
the PLT-22 transceiver transmit and receive mode currents and the wide (+8.5VDC
to +16VDC) V

A low transmit duty cycle implies that the device transmits packets infrequently,
e.g., the product waits for a minimum of 10 packet times between transmitting each
packet - a 10% transmit duty cycle. A power supply design that takes advantage of
this duty cycle can store energy on a capacitor during the relatively long period
between transmissions, when the PLT-22 transceiver draws minimal current, and
then consume the stored energy to transmit a packet. This type of power supply,
referred to as an “energy storage power supply,” stores energy by charging an energy
storage capacitor to a relatively high voltage (e.g., 15V) while in receive mode. The
voltage on the capacitor then falls or "droops" toward a lower limit (e.g., 9.0V) while
transmitting. The energy storage capacitor is then slowly recharged to the higher
voltage during the relatively long time between transmissions. Traditionally, the
proper design of such a power supply required knowledge of the maximum transmit
duty cycle to be supported, and an implementation that accounted for all worst case

operating voltage of the PLT-22 transceiver.

A

LONWORKS PLT-22 Transceiver User’s Guide 3-3

operating conditions (temperature, line voltage, component variation and
transmitter loading).

The cost of such a power supply can be significantly reduced if, instead of designing
the supply for the maximum possible transmit duty cycle and for the worst case
environmental conditions, the supply can be designed for typical operating
conditions. However, designing for typical operating conditions implies that a
mechanism exists to "manage" the worst case operating conditions such that reliable
operation is assured. This management feature must also address products whose
operating conditions (especially transmit duty cycle) are not defined prior to use in a
network, but rather are controlled by application programs loaded after installation.

The PLT-22 power management feature implements the needed management
functionality by intelligently monitoring the energy storage power supply. Should
the node attempt to transmit too frequently, the power management feature
enforces a limit on the transmit duty cycle by preventing the Neuron Chip from
transmitting until the node's power supply recovers to the point that sufficient
energy is available to transmit a packet. Details of this feature and application
examples are provided in Chapter 5.

When power management is enabled, the PLT-22 transceiver requires a V

A

power supply voltage of 12.9V before it will attempt to transmit a packet.
Products with fixed V

power supplies lower than 12.9V should never be

A

programmed to enable the power management feature as they may never
be allowed to transmit. Likewise a node whose power supply relies on
power management to operate correctly should never

be programmed with

the power management feature disabled.

The user can enable or disable power management at the time of channel definition
by selecting a standard transceiver type with a "low" suffix. The only difference
between a set of standard transceiver parameters with the "low" suffix and the
corresponding set without the "low" suffix is that the power management feature is
enabled with the "low" set and disabled with the set without the suffix.

Note that some installation tools load a device's communication parameters as part
of the installation and replacement process and calculate those parameters based on
the channel (rather than the particular device). Such tools can not be used for
systems that contain a mixture of nodes with and without power management
enabled on the same channel.

Tools based on the L

ONWORKS Network Services (LNS) architecture, such as

LonMaker for Windows Integration Tool, correctly support all configurations of PLT­22 (and PLT-21) nodes with or without power management. For a tool not based on
LNS, contact your tool vendor to determine if it can support a mixture of power
management and non-power management nodes on the same channel.

Standard Transceiver Types

Four standard transceiver types are defined for the PLT-22 transceiver operating in
the 110 kHz – 140kHz range. These standard transceiver types specify
communications parameters for a PLT-22 (or PLT-20 or PLT-21) node. The

3-4 PLT-22 Transceiver Programming