5-26Aux Outputs Menu
Voltage This menu box displays the fixed voltage at the selected aux output. This
menu box is only displayed if the output is Fixed.
If the output is Fixed, pressing this key will select the voltage as the
active entry field. The fixed voltage level can be adjusted with the knob or
entered from the keypad. The voltage can range from -10 V to +10 V with
1 mV resolution.
Sweep Limits An output which is in linear or log sweep mode has its sweep limits and
offset value displayed.
A swept output is a linear or logarithmic progression from the start value
to the stop value, plus the offset value. Sweeps are computed based
upon the start and stop values and then offset by the offset value. This
allows a single definition to work for both linear and log sweeps. For
example, a linear sweep with a start of 1 V and a stop of 5 V and an
offset of -4 V will sweep linearly from -3 V to 1 V. A log sweep with the
same parameters will be computed as a sweep from 1 V to 5 V (a factor
of 5) and then be offset by -4 V. This allows log sweeps to provide nega-
tive outputs (for which log is not defined).
The sweep limits can range from 0.001 V to 21 V and the offset can
range from -10.5 V to +10.5 V. Outputs cannot be programmed to be out-
side the -10.5 V to 10.5 V range. Adjusting the limits such that an output
voltage would be outside this range will change the offset in the opposite
direction to pin the outputs to -10.5 V or 10.5 V. The same is true when
adjusting the offset - the limits will change to pin the outputs.
To number of points in the scan and the limits determine the actual
sweep progression. The number of points is the scan (sweep) length
multiplied by the sample rate. A 100 second scan with a 4 Hz sample
rate has 400 points. This is how many data points will be recorded in this
scan as well as the number of points in the sweep.
A linear sweep divides the sweep range (stop-start) into N equal incre-
ments where N is the number of points in the sweep. If the increment is
less than 1 mV, then two or more successive points may have the same
output value.
A log progression is one where the ratio of each point to the previous
point is a constant.
Vi = Vi-1 x k
If N points are required to progress from the start to the stop, then k is
determined by
Vstop = Vstart x k N
The start and stop voltages are restricted to positive values from 0.001 V
to 21 V.