Teledyne LeCroy Automation API for IBTrainer Software Ver.2.0 - Manual (Page 16)

Programming the IBTrainer Packet Handling Concept
1-6 CATC IBTrainer InfiniBand Exerciser API Reference
Error Mechanism for the TCL Interface
The following example script shows how an IB Trainer gets connected
using the TCL script language and shows the error mechanism in case
the connect was not successful.
if { [catch {
set portnum 0
set gen [new_IGCGenerator]
IGCGenerator_Connect $gen $portnum
} result]} {
# error while establishing connection
puts stderr "ERROR: Cannot connect to generator at port $portnum:
$result"
} else {
puts "Connected on port $portnum"
}
In order to throw an error, use the following script command.
error "Fatal error: Cannot <do whatever the task was>"
The error command terminates the script unless the error is caught by
a catch command. Errors from the class igapi are automatically caught,
that is, the error message is printed to stderr (interactive mode) and the
corresponding tcl function returns with TCL_ERROR.