Related Special Functions; Disable Settling; Sweep Up And Down On - HP 8642A Operation And Calibration Manual

Operation Model 8642A/B
RF Frequency Sweep (cont'd)
Related Special
Functions
Related
Operating
Instructions
3-66
il9. Disable Settling. ThIs special function allows the Signal Generator's
microprocessor to respond to new commands without waiting for the internal circuitry to
settle. When using this special function, it's possible to select a function before the
previous function has finished settling. When settling is disabled, response time is
improved by up to 40 ms: Special Function 119 disables out-of-Iock messages.
219. rre-enahle Settling. This special function re-enables the settling that is disabled
when Special Function 119 is selected.
12.1. Sweep Up and Down On. During auto or single sweep modes, the Signal
Generator sweeps from the start end-point to the stop end-point and then sweeps from
the stop end-point to the start end-point in the same amount of time. See Figure
3-7
below for a comparison of the normal sweep mode (Sweep Up and Down Off; Special
Function 221) and the up and down sweep mode (Sweep Up and Down On; Special
Function 121). (The waveforms are not drawn to scale). There is no start-of-sweep
settling time when this special function is selected. Also, Z AXIS is always a TTL low.
221. Sweep Up and Down Off. This special fUIlction re-enables the normal sweep
disabled with Special Function 121. Special Function 221 sets the Signal Generator to
sweep from the start end-point to the stop end-point, and then again from the start
end-point to the stop end-point.
>-
::>
a.
>-
::>
o
'"
H
X
<t
I
X
NORMAL SWEEP MODE
>-
::>
a.
>-
::>
o
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H
X
<t
I
X
UP AND DOWN SWEEP MODE
Figure 3-7. Sweep Waveforms
Refer to RF Frequency (page 3-39) for additional information that also applies to RF
frequency sweep.
Refer to Knob (page 3-141) and Step, Increment Set (page 3·-149) for information on
using these to modify settings.
Refer to Operating Messages (page 3-177) if the instrument displays a message you want
clarified.
Refer to Special Functions (page 3-165) for information about the way these are
accessed.