Sifos Technologies PowerSync PSA100, Technical Reference Manual, Page: 130 / 147

PowerSync Analyzer Reference Manual
March 9, 2010 Sifos Technologies page 130
8.2. Intra-Port Interaction Testing
The PowerSync Analyzer has been developed to readily support measurements that span across multiple PSE ports,
even if those ports are connected through multiple PSA chassis’. The two features that enable such testing are:
•
External Triggering (
see Section 2.3.2
)
•
The TRIG Out BNC Port on the PSA Controller Blade
External Triggering provides a mechanism where by events that occur on one port may be visible to all ports across all
chassis’. External Triggers can be generated by user selected events, such as the initiation of a current load transient,
and they can be used to trigger measurements, such as a minimum peak voltage measurement over a user-defined time
interval.
Additionally, external triggers can be utilized to initiate current load transients. This feature allows the current
transient resource within each test port to act as a mechanism for internal trigger (or waveform transition events) to be
transferred to external trigger events.
An example of intra-port interaction testing would be to examine the affect on PoE line voltage on one or more ports
caused by a sudden load transient occurring on one or more other ports. In this test case, external triggering will be
used to:
•
Launch load transients concurrently on M ports
•
Launch Vpeak measurements concurrently on N ports
Intra-Port Interaction Tests can be configured and carried out from both PowerSync Interactive as well as PowerShell
where specialized scripts can be developed. The example below provides some PowerShell command sequences that
would be relevant to an interaction test where effects of load current transients are to be analyzed.
A demo script that performs such a test is “psa_cross_port.tcl”.
This example script would produce and output as follows:
# Assign load ports
set loadPorts "1,1 1,2 2,1 2,2"
set testPorts "3,1 3,2 4,1 4,2 5,1 5,2"
# Power all the ports that will experience load transients to 4 Watts
# Configure the load transients for 350 mA over 45 mSec
foreach port $loadPorts {
power_port $port p 4.0
itrans $port i1 350 t1 45m i2 40 t2 55m ext
}
# Power all the ports that will be measured to 7 Watts
# Configure the peak voltage meter to capture a voltage transient
foreach port $testPorts {
power_port $port p 7.0
vdcpeak $port trig ext period 100m min timeout 10
}
# Initiate the triggered voltage measurements
foreach port $testPorts {
vdcpeak $port stat
}
# Launch the current transients and trigger the peak voltage measurements
trigout 1,1
after 100
# Recover the peak voltage measurements
foreach port $testPorts {
set MinV($port) [lindex [
vdcpeak $port stat] 3]
}
# Present the results
parray MinV