Sifos Technologies PowerSync PSA100, Technical Reference Manual, Page: 139 / 147

PowerSync Analyzer Reference Manual
March 9, 2010 Sifos Technologies page 139
8.4.4. Automatically Terminating PowerShell TCL Upon Script Execution
PowerShell TCL can automatically terminate upon completion of either a Pre-Defined Batch Process or a Remote
Command Processing session. This feature is also enabled by a simple edit to the PowerShell TCL resource file:
c:\Program Files\Sifos\PSA1200\tclshrc.tcl
At the very bottom of the resource file is a header followed by the command,
exit
commented out. By removing the “#” TCL comment character, the exit command will become the final command
executed in PowerShell and the PowerShell console or session will close automatically.
If the Remote Command Processing mode is invoked via the
psa_echo
command discussed above, then the
command
psa_echo_off
must be passed to PowerShell TCL so that it can move on to exit the session.
8.5. Integrated Power-over-Ethernet and Packet Transmission Testing
Popular Ethernet transmission test and load instruments are equipped with TCL-based programming and interactive
control capabilities. Since PowerShell utilizes TCL, the opportunity exists to combine libraries under a single console
and execute test scripts written to control both PowerSync Analyzers and Ethernet test equipment.
This capability gives script developers the option to generate efficient tests that can:
•
Evaluate impact of Powered-Device emulations on transmission integrity
•
Evaluate impact of data transmission signals on PoE voltages
•
Parallel test PoE characteristics and Data Transmission characteristics in the interest of minimizing total
test time.
Powered-Device emulations may take the form of various load
changes and rapid load transient conditions. These are readily
controlled utilizing PowerShell commands discussed earlier in
Section 4. During a packet transmission and capture sequence,
a test script could run various scenarios of load transients and
transitions, then evaluate any negative consequences to packet
transmission. The standard test script,
psa_test_load
described
in Sections 3.2.1 and 4.8 provides a flexible means to generate
active load sequences that can operate concurrently with a data
transmission test.
The impact of data transmission on PoE bus voltage is readily
analyzed using the AC Meter and/or Peak Voltage Meter. A
test script might vary packet rate and packet size looking for any evidence of signal “leakage” onto the DC voltage rail.
Spirent’s SmartBits products are an example of a Ethernet performance tester offering a TCL API for automated script
development. The following sequence of commands may be used in a PowerShell console to integrate in the SmartLib
TCL API to PowerShell.
set smartPath "c:/Program Files/SmartBits/SmartLib"
set smartTcl "Tcl/TclFiles"
set smartComm "Commlib"
# Determine that Smart Lib is installed in the typical place
if { [file exists "$smartPath/$smartTcl/smartlib.tcl"] == 0 } {
# ==================================================================================
# REMOVE '#' BELOW IF YOU WANT TCL SHELL TO TERMINATE UPON COMPLETION OF COMMANDS &
# SCRIPTS
exit
Figure 8.14
Load Sequencing from
psa_test_load