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Section 2: General operation
Model 2657A High Power System SourceMeter® Instrument Reference Manual
2-24
2657A-901-01 Rev. B/December 2012
NPLC caching
NPLC caching speeds up operation by caching A/D reference and zero values for up to the ten most
recent measurement aperture settings. Whenever the integration rate is changed using the SPEED
key, or a user setup is recalled, the NPLC cache is checked. If the integration rate is already stored in
the cache, the stored reference and zero values are recalled and used. If the integration rate is not
already stored in the cache, a reference and zero value will be acquired and stored in the cache when
the next measurement is made. If there are already ten NPLC values stored, the oldest one will be
overwritten by the newest one. When autozero is off, NPLC values stored in the cache will be used
regardless of age.
Basic source-measure procedure
Front-panel source-measure procedure
Use the following procedure to perform the basic source-measure operations of the Model 2657A.
The following procedure assumes that the Model 2657A is already connected to the device under test
(DUT), as explained in
Hazardous voltages may be present on all output and guard terminals. To prevent electrical shock
that could cause injury or death, never make or break connections to the Model 2657A while the
instrument is powered on. Turn off the equipment from the front panel or disconnect the main
power cord from the rear of the Model 2657A before handling cables. Putting the equipment into
standby does not guarantee that the outputs are powered off if a hardware or software fault occurs.
Step 1: Select and set the source level
Perform the following steps to select the source and edit the source value:
1. Press
the
SRC
key as needed to select the voltage source or current source, as indicated by the
units in the source field on the display. The flashing digit (cursor) indicates which value is
presently selected for editing.
2. Move the cursor to the digit to change, then press the navigation wheel
to enter the EDIT
mode, as indicated by the EDIT indicator.
3. Use
the
RANGE
keys to select a range that will accommodate the value you want to set. See
(on page 2-72) for more information. For best accuracy, use the lowest possible source
range.
4. Enter the source value.
5. Press
the
ENTER
key or the navigation wheel
to complete editing.
Step 2: Set the compliance limit
Perform the following steps to edit the compliance limit value:
1. Press
the
LIMIT
key.
2. Move the cursor to the digit to change, then press the navigation wheel
to enter the EDIT
mode, as indicated by the EDIT indicator.
3. Enter the limit value, then press the
ENTER
key or the navigation wheel
to complete editing.
WARNING
Содержание 2657A
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