Pressing
next
calls the pulse train period screen:
Enter pulse train
period:
100·0us
◊
done next
◊
The period can be set, with 4-digit resolution, from 133·3ns to 100s by direct keyboard entries or
by using the rotary control.
Pressing
next
calls the baseline voltage screen, the last of the general setup screens:
Enter the baseline
voltage:
+0·000 V
◊
done next
◊
The baseline is the signal level between the end of one pulse and the start of the next, i.e. it is the
level all pulses start and finish at. The baseline can be set between -5·0V and +5·0V by direct
keyboard entries or by using the rotary control. Note that the
actual
baseline level at the output
will only be as set in this field if the output amplitude is set to maximum (10Vpp into 50
Ω
) on the
AMPLITUDE screen and terminated in 50
Ω
. If the amplitude was set to 5Vpp into 50
Ω
then the
actual baseline range would be -2·5V to +2·5V for set values of -5·0 to +5·0V, i.e. the amplitude
control “scales” the baseline setting. The actual output levels are doubled when the output is
unterminated.
Pressing
next
on this screen calls the first of 3 screens for the first pulse in the pattern:
◊
Pulse 1 level
♦
+5·000 V
◊
done next
◊
The pulse level can be set on this screen between -5·0V and +5·0V by direct keyboard entries or
by using the rotary control. As with the baseline level described above the set pulse levels are
only output if the amplitude setting is set to maximum (10Vpp into 50
Ω
) on the AMPLITUDE
screen and terminated in 50
Ω
. Adjusting the amplitude “scales” both the peak pulse levels and
baseline together, thus keeping the pulse shape in proportion as the amplitude is changed,
exactly as for arb waveforms. Actual output levels are doubled when the output is unterminated.
Note that by pressing the
Pulse
softkey on this (and subsequent screens) the pulse to be edited
can be directly set from the keyboard or by using the rotary control; this is useful in directly
accessing a particular pulse in a long pulse train instead of having to step through the whole
sequence.
Pressing
next
calls the pulse width screen for the first pulse:
◊
Pulse 1 width
♦
program 25·00 us
(actual 25·00 us)
◊
done next
◊
The width can be entered directly from the keyboard or by using the rotary control. Any value in
the range 33·33ns to 99·99s can be programmed but the
actual
value may differ; for this reason
the
actual
pulse width is shown (in brackets) below the
program
width. The variation between
program
and
actual
will only really be noticeable for very short pulse-train periods (only a few
points in the pulse-train) and very long periods (each of the 50,000 points has a long dwell time)
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