Duration; Externally Triggered Waveforms - Keithley 6220 DC User Manual

Model 6220/6221 User's Manual

Duration

The duration setting defines how long the waveform is generated. You can set the
duration in time over a range of 100ns to 999999.999s, in cycles from 0.001 to
99999999900 cycles (provided the equivalent time, cycles/frequency does not
exceed the upper time duration limit), or choose a continuous waveform (INFinite
setting). From the front panel, you can only specify a time duration from 0.001s to
999999.999s and a cycle duration as an integer number of cycles between 1 and
99999999900.
When a waveform is armed, the execution time is determined based on the explic-
itly programmed time duration or calculated from the specified cycles or duration
settings. The time duration cannot be changed while a waveform is armed. If the
frequency is changed while the waveform is armed, the existing execution time
will remain fixed. The equivalent time duration will not be recalculated even if the
duration is set to cycles. If the same number of cycles is desired at the new fre-
quency, the wave function should be aborted and then re-armed to force the recal-
culation of waveform execution time.

Externally triggered waveforms

Model 6221 units with firmware revision A03 or later include a mode to trigger the
arbitrary waveform generator using the instrument's trigger link lines. When this
mode is enabled, the instrument waits for an external trigger pulse on a specified
trigger link line and starts the configured waveform within 1μs of the falling edge of
the trigger pulse.
This manual section summarizes front panel menu selections and remote com-
mands to control this mode. For complete details on using externally triggering
waveforms, see Section 7 of the Model 6220/6221 Reference Manual.
Return to Section 7 topics
Wave Functions (6221 Only) 7-7