GEH-6385 Reference and Troubleshooting, 2300 V Dr ives Chapter 4 Wizards
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Pulse Test: Timer Configur ation

The Pulse Test allows up to two vol tage pulses to be commanded and produced by
the power bridge. The duration of the voltage pulses, and the duration of the current
decay time between the pulses and after the pulses, is specified by the pulse test
timer parameters Pulse 1 on time, Pulse 2 on time, Mid pulse off time, and Post pulse
off time.
The diagram below shows a Pulse Test profile and indicates how the timer
parameters are defined.
Off
Park
Pulse
Time
Pulse 1
on time
Mid pulse
off time
Pulse 2
on time
Post pulse
off time
All the timer parameters have units of seconds. If any of the parameters equals zero,
the corresponding pulse on or off time is skipped during the Pulse Test.
The user should keep sever al issues in mind when specifying th ese times. First it is
possible for large currents to develop in the bridge as result of these pulses. The
power bridge will protect itself against excessively large currents by declaring an
IOC fault. Any fault will abort the pulse test sequence and require you to perform a
fault reset before an other pulse can be commanded. The secon d issue is that there are
several constraints which the pulse test wizard must deal with when issuing pulses.
Among these are minimum pulse widths, lockout times and transition con straints.
The wizard must always obser ve these constraints. As a resu lt you may not get the
exact pulse you command or in some cases you may get no pulse at all. For instance,
if you declare a pulse that is smaller than the required minim um pulse then you will
get no pulse. Finally you sh ould be aware that the pulse test wizar d always schedules
the end of the mid pulse off time to occur on a task 1 boundary. This is the pivot
point of the sequence an d all other timings are computed from this point.

Pulse Test: Operation

The Pulse Test is a diagn ostic test that produces a current p ulse in the power bridge
and load.
After specifying th e Pulse Test configuration parameters, click on the Execute button
to invoke the Pulse Test.
Remaining Parameter Setup
The Remaining Para meter Setup wizard directs con figuration of parameters that
cannot be assi gned default va lues during the com missioning pr ocess. It is
recommended that th e control be allowed to calculate the default parameter settin gs.