3
Set a second PLCA-22 analyzer in
Send
,
UnackPri
, and
C-band
modes
(referred to as the Send PLCA-22 analyzer) and configure the coupling switch for
external coupling. Connect the PLCA-22 analyzer using the attenuation circuit
(30k
Ω
resistor; figure 7-5) and the PL-20 Line-to-Neutral coupler as shown in
figure 7.9. Note that the line cord of the Send PLCA-22 analyzer is connected to
the power mains on the input side of the isolator to prevent communications
between the two PLCA-22 analyzers via parasitic line cord coupling.
4
Set the following parameters on the Send PLCA-22 analyzer:
Number of Packets
= 1000 (1k)
Packet Length
= 13 bytes
TxVpp
=
3.5V
Attn
=
0
dB
Note that 3.5Vp-p should always be used for TxVpp even if the UUT is
configured for 7Vp-p output. This provides a common reference against which
the receive sensitivity of any UUT can be measured.
5
Connect the UUT test setup as shown in figure 7.9. Once the Nodeutil utility is
running correctly and the start-up screen shown above is displayed, press the
service switch on the UUT. This will cause Nodeutil to register the service pin
message received from the device. Select the “S” command to obtain the status
from the UUT (the entry in the results screen named “Packets received by node”
is the number of uncorrupted packets received by the UUT since the last time the
statistics were cleared). Type “Y” at the prompt to clear the status of the UUT.
The S command will be used in the next few steps to obtain the received packet
count from the UUT. Be sure to clear the status of the UUT after each reading.
6
Press START on the Send PLCA-22 analyzer. The test will begin and the receive
packet count on the Recv PLCA-22 analyzer should increment with a packet
error rate very close to 0% (<1%). The -60dB LED on the primary frequency
signal strength meter on the Recv PLCA-22 analyzer should illuminate,
indicating that the received signal is approximately -60dB relative to the
nominal 3.5Vp-p transmit signal. The -60dB level serves as a starting point;
additional attenuation will be added via the
Attn
function of the Send PLCA-22
analyzer.
7
Once the Send PLCA-22 analyzer has transmitted 1000 packets, obtain the
received packet count from the UUT using the "S" command of the Nodeutil
utility. Record that value and the packet error rate of the Recv PLCA-22's
analyzer in columns 4 and 5 of table 7.1. Calculate the error value as a
percentage by subtracting the number of packets received by the node from 1011
and then dividing by 10 (divide by 1000 then multiply by 100) and record the
result in the rightmost column of table 7.1. This procedure yields a sufficiently
accurate approximation of the actual packet error rate. Refer to the notes at the
end of these steps for details.
L
ON
W
ORKS
PLT-22 Transceiver User’s Guide
7-13
Summary of Contents for LONWORKS PLT-22
Page 6: ...iv Echelon...
Page 14: ...1 8 Introduction...
Page 67: ...LONWORKS PLT 22 Transceiver s User Guide 5 7 Figure 5 3 Capacitor Input Power Supply Schematic...
Page 92: ...6 10 Design and Test for Electromagnetic Compatibility...
Page 110: ...7 18 Communication Performance Verification...
Page 114: ...8 4 References...
Page 118: ...A 4 Appendix A...
