Specifications

PL 3120/PL 3150/PL 3170 Power Line Smart Transceiver Data Book 239
The interface board performs three functions:
• The 4.7 ohm resistor in series with the 1uF X2 capacitor provides a low impedance load for the transmit level
verification test.
• The 15k ohm resistor, in conjunction with the 4.7 ohm resistor and 1uF X2 capacitor, provide approximately
70dB of attenuation of the message generated by the D/A converter as part of the receive mode test.
• The 1N4148 diode, 0.1uF capacitor, 100k ohm resistor, 100 ohm resistor, and 2N3904 transistor provide a peak
detect function to trigger the A/D converter when a packet is transmitted by the UUT in response to the
message generated by the D/A converter.
A circuit, such as the one in Figure 7.1 of Chapter 7, should be used for the block in Figure D1 labeled “Isolation”. A
Line-to-Neutral coupler such as Echelon model number 78200-221 should be used for the block in the figure labeled
“230VAC L-N Coupler”.
Software Description
Input file
A file containing either the C-band or A-band waveform that represents the Query ID broadcast message should be used
as an input to the software. The data file represents amplitude in volts while the interval between data points is 1µs. Any
unconfigured device with a PL Smart Transceiver will respond to the appropriate waveform by transmitting its Neuron
ID. The files are available as a free download from the Echelon Web site (go to www.echelon.com/downloads
and select
the Transceivers category).
Test process
1. Read the waveform data into a buffer called waveform[].
2. Scale the waveform by applying proper gain and offset to produce a 7V p-p waveform prior to the attenuation circuit.
The waveform should be centered on zero volts.
3. Prepare the A/D channel to be ready for capturing the response of the UUT upon receiving a trigger signal from the
interface board.
4. Output the waveform[] signal to the UUT through the A/D channel.
5. When the UUT receives the signal, it will respond with a message that contains the Neuron ID. This will take place
within a few hundred milliseconds.
6. Capture the response and calculate the RMS voltage over the first 35 bits. The measurement window should be
6.36ms for C-band and 9.7ms for A-band.
The test limit for the RMS voltage depends on the transceiver channel type and amplifier type of the UUT. The table
below lists recommended limits.
Table D.1 Test Limits of Different Transceiver Types
UUT Transceiver and Amplifier Type
V
RMS
C-band 7V p-p/1A
0.8 (0.65 for 1-phase
L-E coupling)
C-band 10V p-p/2A 1.3
A-band 7V p-p/1A 0.8
A-band 8V p-p/2A 1.2
Figure D.2 shows a complete test cycle with respect to transmit, receive, and trigger signals (the signal levels and
timings in the figure are not to scale but are meant to illustrate the measurement concepts).