1、 CEA Standard Control Network Power Line (PL) Channel Specification CEA-709.2-A R-2012 June 2000 NOTICE Consumer Electronics Association (CEA) Standards, Bulletins and other technical publications are designed to serve the public interest through eliminating misunderstandings between manufacturers a
2、nd purchasers, facilitating interchangeability and improvement of products, and assisting the purchaser in selecting and obtaining with minimum delay the proper product for his particular need. Existence of such Standards, Bulletins and other technical publications shall not in any respect preclude
3、any member or nonmember of CEA from manufacturing or selling products not conforming to such Standards, Bulletins or other technical publications, nor shall the existence of such Standards, Bulletins and other technical publications preclude their voluntary use by those other than CEA members, wheth
4、er the standard is to be used either domestically or internationally. Standards, Bulletins and other technical publications are adopted by CEA in accordance with the American National Standards Institute (ANSI) patent policy. By such action, CEA does not assume any liability to any patent owner, nor
5、 does it assume any obligation whatever to parties adopting the Standard, Bulletin or other technical publication. This document does not purport to address all safety problems associated with its use or all applicable regulatory requirements. It is the responsibility of the user of this document to
6、 establish appropriate safety and health practices and to determine the applicability of regulatory limitations before its use. This document is copyrighted by the Consumer Electronics Association (CEA) and may not be reproduced, in whole or part, without written permission. Federal copyright law pr
7、ohibits unauthorized reproduction of this document by any means. Organizations may obtain permission to reproduce a limited number of copies by entering into a license agreement. Requests to reproduce text, data, charts, figures or other material should be made to CEA. (Formulated under the cognizan
8、ce of the CEA R7 Home Networks Committee.) Published by CONSUMER ELECTRONICS ASSOCIATION 2012 Technology 2) this specification lacks control over the installation of the power line medium, its physical properties, topology, or other devices connected to the medium. An overview of the physical and el
9、ectrical characteristics that may be found in a typical power line environment is given in Annex A and B. 4.3 Connectors If a connector is used to attach an EIA-709.2 node to the power line network (as opposed to a direct connection), then the connector shall meet the following requirements: The con
10、nector shall impose a negligible signal loss (less than 0.1dB) from the power line network and the attached node. The connector shall not impose any signal or voltage loss (less than 0.1dB) to the power line network (with or without a node connected to the connector). Power line node connectors are
11、assumed to fit standard home electrical outlets appropriate for the country of use. In North America these include 120 V AC duplex polarized and unpolarized, and keyed 240 V AC connectors. NEMA 120 V AC (15-20A) connectors are assumed to contact only one side (L1 or L2) of the local power line netwo
12、rk. EIA-709.2 nodes may incorporate connectors with or without ground contacts. EIA-709.2 nodes that incorporate a ground contact may use the standard L-N coupling or the optional L-G coupling described in 5.5.4. An EIA-709.2 node without ground contact should function normally using only L-N coupli
13、ng. 4.4 Installation Requirements and Guidelines This section discusses the installation of the nodes within the EIA-709.2 environment. The installer should follow the practices described in this section. Failure to comply with these practices may lead to poor reliability, degrada-tion of system per
14、formance (perhaps outside specified operating ranges), and system failure. 4.4.1 Signal Coupling between L1 and L2 Home 120 V AC electrical devices (appliances, lights motors, etc.) normally connect to either L1 or L2. Only 240 V AC devices that connect to L1 and L2 simultaneously provide a signal p
15、ath between these two branches other than the minimal coupling provided by the distribution transformer and the mutual inductance of the wiring. Therefore, a potential problem can exist on a power line network in that an EIA-709.2 120 V AC node on L1-N may not com-municate with an EIA-709.2 120 V AC
16、 node on L2-N due to inadequate signal coupling between L1 and L2. For the same reason, communication may not occur between EIA-709.2 240 V AC nodes on L1-L2 and EIA-709.2 120 V AC nodes on either L1-N or L2-N. To help solve this problem, a signal coupler should be placed between L1, L2 and Neutral
17、to improve signal propa-gation within the power line network. The coupler is an optional node since its necessity depends on the installation. See Annex B.3 for specifications of the coupler. 4.4.2 Surge Protection and Related Devices Certain surge protection and related frequency selective protecti
18、on devices may be installed in the home. These de-vices may attenuate the EIA-709.2 channel waveform sufficiently to prevent operation in part or all of the network. Precautions should be taken such that the device chosen does not substantially attenuate the EIA-709.2 signals in the 125-140 kHz rang
19、e. 5 PL Node Specifications This section covers the Physical Layer specifications of the PL node including: The Physical Layer interface to the MAC Layer. The physical signaling characteristics used on the PL medium. The specification of the transmitter needed to generate the necessary PL signals. 7
20、CEA-709.2-A The specification of the receiver needed for proper reception of PL signals. 5.1 Interface to MAC layer The data is passed from the MAC layer to the PL transceiver in an 8 bit byte format containing a L2Hdr byte, the NPDU and a 16 bit CRC as described in 5.3, 5.4 and 5.5 of EIA-709.1-A.
21、The PL transceiver encodes each byte of data into an 11 bit word and adds a bit sync pattern, a word sync word, and an End-of-Frame consisting of two End-ofPacket (EOP) words. The entire packet is shown below in figure 5. The bit sync pattern consists of 24 bits of al-ternating “10“. The word sync w
22、ord is “11001111011“. The EndofPacket word is “11100110011“. The bit sync pat-tern provides clock timing information. The word sync pattern provides bit polarity and word boundary information. Bit Sync Word Sync L2HDR+NPDU+CRC EOP EOP10101010101010101010101011001111011N 11 bit words11100110011111001
23、10011Figure 5 Power Line Packet Format 5.2 Word Encoding Each 8-bit byte in the L2Hdr, the NPDU and the CRC is encoded into an 11-bit word as follows. The first 8 bits of the 11-bit word are the 8 bits of data that are transmitted in NRZ format (uncoded). Bit 9 is an even parity bit P for the first
24、9 bits. Bits 10 and 11 are the last two bits and are always 01. A data word is shown in figure 6. 8 bit word from MAC layer P 0 1MSB LSBFigure 6 11-bit Word Format 5.3 PL Packet Timing As described in EIA-709.1-A, the EIA-709 protocol uses an interpacket spacing defined as a Beta1 time and ran-domiz
25、ing slots defined as Beta2 times. Beta1 is measured from the end of a packet to the beginning of the first Beta2 slot. The EIA-709.1-A protocol and PL transceiver in combination must produce a Beta1 time of 3.4 ms 0.1 ms and B2 times of 2.0 ms 0.1 ms each. For optimum communication between EIA-709.2
26、 nodes, there should be 8 priority Beta2 slots. In addition, the EIA-709.2 transceiver shall meet the timing parameters defined below and specified in table 1. Carrier Detect - The time from when the beginning of the packet is at the receivers input until the receiver has detected carrier and caused
27、 P_Channel_Active to be set to true. Transmit Start Delay - The time from when P_Data_request is activated to when the beginning of the packet is initiated onto the power line. Parameter Specification Carrier Detect 1.7 ms max. Transmit Start Delay 100 us max. Table 1 Transceiver Timing Specificatio
28、ns 5.4 Transmitter Characteristics The transmitter shall be a differential driver capable of driving the specified signal on the PL network. 8CEA-709.2-A 5.4.1 Carrier Modulation Each bit is sent as NRZ data BPSK modulated on to a carrier. The carrier frequency is 131.579 kHz with a tolerance of +/-
29、 200 PPM. The symbol rate is 5482.45 symbols/sec with a tolerance of +/- 200 PPM. Note that appropriate shaping must be performed on the modulated waveform to meet the local regulatory requirements for conducted emissions. 5.4.2 Waveform Amplitude The amplitude of the carrier output voltage during p
30、acket transmission should be measured at 23 degrees C +/- 3 degrees C using the test circuit shown in figure 7. The V-network is an artificial network of (50 /(50 H+5 ) conforming to subclause 8.2.1 of CISPR Publication 163. The amplitude is measured using the tuned receiver at a frequency of 131.5
31、kHz with a peak detector and a 30 kHz resolution bandwidth. The tuned receiver using its peak detector should read the rms value of a sinusoid. The amplitude limits must be met both with switch closed and with the switch open. The transmit voltage will be calculated using the following formula Vpp=2
32、.828*Vmeasuredand dBV=20*log10(Vmeasured). The transmit voltage Vmeasuredmust be greater than 0dBV (2.828 Vpp) and less than 11 dBV (10.0 Vpp) when the switch is open and greater than 12 dBV (0.7 Vpp) when the switch is closed. V-NetworkMeasuringReceiver(50 ohms)Power lineTransceiverunder TestNGLFil
33、terNeutralGroundLine250 uH50 uH.25 uF505550 uH11250 uH .25 uF1switchPower LineFilter (40 dB 130 kHzPower LineFilter (40 dB130 kHz)Figure 7 Test Circuit for Determining Transmit Amplitude 5.4.3 Device Coupling EIA-709.2 devices will couple the control channel signal to the power line in various ways
34、depending on which lines are available and what local electrical code restrictions apply. 9CEA-709.2-A 5.4.3.1 Single Phase Coupling An EIA-709.2 node that does not have access to the ground contact may couple to the power line network using Line and Neutral (L-N) conductors. If a ground contact is
35、available, it may couple to the power line network using Line and Ground (L-G) conductors. The L-G alternative may be subject to electrical code restrictions. 5.4.3.2 Multiple Phase Coupling If an EIA-709.2 node has access to more than one phase and neutral then either or both phases may be used to
36、cou-ple with respect to neutral, e.g. (L1-N) and/or (L2-N). If the node has access to the ground contact and local codes allow it, then the phases may be coupled with respect to ground e.g. (L1-G) and/or (L2-G). 5.5 Receiver Characteristics This section describes the impedance and performance specif
37、ications of the PL transceivers receiver, which shall be measured for conformance purposes at an ambient temperature of 23 +/- 3 degrees C. 5.5.1 Receive Mode Effective Input Impedance The receive-mode effective input impedance shall be measured using the test circuit shown in figure 8. The V-networ
38、k is an artificial network of (50 /(50 H+5 ) conforming to subclause 8.2.1 of CISPR Publication 163. The receiver impedance is measured as follows. Set the signal generator to a sine wave of amplitude 5 V peak-to-peak at a frequency of 131.5 kHz. All measurements are made with a tuned receiver using
39、 a peak detector and a 30 kHz resolution bandwidth. The tuned receiver using its peak detector should read the rms value of a sinusoid. With the transceiver unplugged, measure the voltage (Voc) on the V-network 50 resistor (the signal generator provides this resistor with its internal termination) w
40、ith the tuned receiver. The voltage Vocshould be 5.5 dBV 1dB (5.3 volts peak to peak 10%) where dBV is defined as dBV=20*Log10(Vpp/2.828). Next, with the transceiver plugged in and powered up in receive mode measure the voltage (Vic) on the V-network 50 resistor. The effective receive input impedanc
41、e is calculated with the following formula where Zeis the effective receiver input impedance, Znis a constant value of 29,Vocand Vicare the two voltages measured as described above (they must be corrected for the 1/10 divider). The calculated value for Zemust be greater than or equal to 200. ZVZVZVZ
42、eicnoc n ic n+ +50(50 ) (50 )10CEA-709.2-A Power lineTransceiverunder TestV-NetworkNPower LineFilter(40 dB 130 kHz)Power LineFilter(40 dB 130 kHz) LMeasuringReceiver(50 ohms)GSignalGenerator(50 ohms)FilterLineNeutralGround.25 uF50 uH5.25 uF250 uH55050 uH1250 uH450Figure 8 Test Circuit for Determinin
43、g Effective Receiver Impedance 5.5.2 Receiver Performance There are four receiver performance specifications. The performance is measured under various conditions as de-scribed in the following sections for each of the four tests. The performance metric used is packet error rate (PER%) which is defi
44、ned by the equation below where Pris packets received and Psis packets sent. The number of packets sent (Ps) must be more than 1000. PERPPrs% =100 1 The test circuit for all of the receiver performance tests is shown in figure 9. The V-networks shown must conform to the same standard as described in
45、 5.6.1. The tuned receiver should be using a peak detector, a resolution band-width of 10 kHz (10 kHz is wide enough to encompass the power line signal and is a commonly available filter bandwidth in standard measuring equipment) and a video bandwidth of 30 Hz. The tuned receiver using its peak dete
46、ctor should read the rms value of a sinusoid. Note that the tuned receiver is measuring 1/10 of the actual voltage on the 50 resistor of the V-network. When a test does not use the signal generators output care must be taken to insure that the 50 termination is still present. In this case, the signa
47、l generator can be either set to 0 amplitude or can be removed and replaced with a 50 termination. 11CEA-709.2-A LGNReceiverUnder TestDimmer CircuitMeasuringReceiver(50 ohms)SignalGenerator(50 ohms)V-NetworkTransmitterNGLNotchCircuitFilterV-NetworkFilterNeutralGroundLineSW2Switch1 uF4501 uFSW1Switch
48、50.1 uFR150k, 10 turnFigure 9 Test Circuit for Receiver Performance 5.5.2.1 Receiving on a Quiet Line The quiet line test is performed using the test set-up shown in figure 9. Switches SW1 and SW2 are open. The packet error rate is measured when there are no impairments and the received signal level
49、 ranges from -60 dBV (2.828 mV peak to peak) to at least 9 dBV (8 V peak to peak). (8 V is chosen as a reasonable compromise between node design complexity, performance and ease of testing) The received signal level is measured across the V-network 50 resistor using the measuring receiver while the transmitter is sending packets. Adjusting R1 sets the received level. The verification procedure is to check performance at each endpoint i.e. at -60 dBV and 9 dBV where the PER% must be 100 (at +90 degree
