Keysight E6640A, Measurement Applications User & Programmer Reference

Page: 1283 / 2870

10 Spectrum Emission Mask Measurement
Sweep/Control
GSM: 4.615383
State Saved Saved in instrument state
Min 100.000 ns
Max 559.0000 ms
Default Unit S
Initial S/W Revision Prior to A.02.00
Offset
Adjusts the accumulated offset between the periodic timer events and the trigger event. Adjusting the
accumulated offset is different than setting an offset, and requires explanation.
The periodic timer is usually not synchronized with any external events, so the timing of its output events
has no absolute meaning. Since the timing relative to external events (RF signals) is important, you need to
be able to adjust (offset) it. However, you have no direct way to see when the periodic timer events occur.
All that you can see is the trigger timing. When you want to adjust the trigger timing, you will be changing
the internal offset between the periodic timer events and the trigger event. Because the absolute value of
that internal offset is unknown, we will just call that the accumulated offset. Whenever the Offset
parameter is changed, you are changing that accumulated offset. You can reset the displayed offset using
Reset Offset Display. Changing the display does not change the value of the accumulated offset, and you
can still make additional changes to accumulated offset.
To avoid ambiguity, we define that an increase in the "offset" parameter, either from the knob or the SCPI
adjust command, serves to delay the timing of the trigger event.
Key Path
Trigger, Periodic Timer
Remote Command :TRIGger[:SEQuence]:FRAMe:OFFSet <time>
:TRIGger[:SEQuence]:FRAMe:OFFSet?
Example TRIG:FRAM:OFFS 1.2 ms
Notes The front panel interface (for example, the knob), and this command, adjust the accumulated offset,
which is shown on the active function display. However, the actual amount sent to the hardware
each time the offset is updated is the delta value, that is, the current accumulated offset value minus
the previous accumulated offset value. Note that the accumulated offset value is essentially arbitrary;
it represents the accumulated offset from the last time the offset was zeroed (with the Reset Offset
Display key).
Note that this command does not change the period of the trigger waveform. Note also that Offset is
used only when the sync source is set to OFF, otherwise delay is used, see section
"Trig Delay" on
page 357 .
An increase in the "offset" parameter, either from the knob or the SCPI adjust command, serves to
delay the timing of the trigger event.
Notes When the SCPI command is sent the value shown on the key (and the Active Function, if this happens
to be the active function) is updated with the new value. However, the actual amount sent to the
hardware is the delta value, that is, the current accumulated offset value minus the previous
accumulated offset value.
The SCPI query simply returns the value currently showing on the key.
W-CDMA & HSPA Measurement Applications Reference 1283