User`s guide

Transient Response
• 40 W/80 W High/Low
Voltage Outputs: 75 µs
maximum to recover to
within 75 mV of nominal
value following a load
change within the range
300 mA to full load for low
voltage units, and 150 mA
to full load for high
voltage units.
• 25 W and 50 W Precision
Outputs: 75 µs maximum
to recover to within 75 mV
of nominal value following a
load change from 0.1 A to
100% of the maximum rated
current.
• N675xA Output Modules:
Less than 100 µs for the
output to recover to within
75 mV of nominal value
following a load change
from 50% to 100% of the
maximum rated current.
• N676xA Output Modules:
Less than 150 µs for the
output to recover to within
75 mV of nominal value
following a load change
from 50% to 100% of the
maximum rated current.
Noise
Please see the comparison
chart in Appendix A for the
noise specifications.
The 662xA uses unique com-
mands that do not follow the
SCPI (Standard Commands for
Programmable Instruments)
standard. These commands
(compatibility commands) have
been built into the N6700A’s
firmware to provide backwards
compatibility and convenience.
The N672xA preconfigured
models are capable of accepting
both compatibility and SCPI
commands. However, mixing
commands may produce
unexpected results. Please
see Appendix D of the N67xxA
User’s Guide for the complete
list of compatibility commands.
Possible Pitfalls When Mixing
SCPI and Compatibility Commands
As mentioned at left, mixing
compatibility and SCPI
commands may produce
unexpected results. This
section will explain one of
the possible pitfalls of mixing
the commands to help avoid
the unexpected.
Measurements
The N675xA modules with
Option 054 and the N676xA
modules have a high-speed
digitizer that take voltage and
current measurements. This
digitizer is programmable and
the sampling rate, number of
points, and measurement win-
dowing, as well as other mea-
surement parameters listed in
Table 3 below, can all be set
using SCPI commands. Any
change to these parameters will
affect the “VOUT?” and “IOUT?”
query responses.
8
Programming/Interfacing
SCPI Command Description Default
SENSe:CURRent:RANGe Sets the DC current measurement range <max>
on models that have multiple ranges
SENSe:VOLTage:RANGe Sets the DC voltage measurement range on <max>
models that have multiple ranges
SENSe:FUNCtion Sets the function for modules without simultaneous “VOLTage”
voltage and current measurement capability
SENSe:SWEep:POINts Defines the number of points in a measurement 1024
SENSe:SWEep: Defines the number of offset points in a measurement 0
OFFSet:POINts
SENSe:SWEep:TINTerval Defines the time period, in seconds, 20.48usec
between measurements
SENSe:WINDow Sets the window function used in RECTangular
DC measurement calculations
Table 3. Default Measurement Settings for N675xA with Option 054 and N676xA