User manual

Mixed Signal Option (MSO, R&S RTO-B1)
R&S
®
RTO
331User Manual 1316.0827.02 ─ 06
D0-D7, D8-D15 ← Signal selection
The buttons select or deselect all digital channels of a pod at once.
Deskew offset ← Signal selection
Sets a general delay for all digital channels. The resulting deskew of a digital channel is
the sum of the general "Deskew offset" and the individual "Deskew".
Threshold setup
Sets the logical threshold. For each sample, the instrument compares the input voltage
with the threshold value. If the input voltage is above the threshold, the signal state "1"
is stored. Otherwise, the signal state "0" is stored if the input voltage is below the thresh-
old.
To avoid the change of signal states due to noise, a hysteresis is considered.
Threshold
Logic 0 Logic 1 Logic 0
Hysteresis
One threshold value is used for a group of four digital channels. For each channel group,
a different threshold and hysteresis can be set. The range of threshold levels and the
minimum voltage swing are given in the data sheet.
There are several ways to set the threshold:
"Threshold"
Enter the value directly in the field.
"Technology"
Selects the threshold voltage for various types of integrated circuits
from a list and applies it to all digital channels. The value is set to "Man-
ual" if a user-defined threshold was entered directly.
"Coupling"
Sets the threshold for all digital channels to the same value. Also the
hysteresis value is applied to all digital channels.
"Hysteresis"
Defines the size of the hysteresis. Three values are available:
●
Normal: the instrument sets a small value suitable for the signal and
its settings. Use this setting for clean signals.
●
Maximum: the instrument sets the maximum value that is possible
and useful for the signal and its settings. Use this setting for noisy
signals.
●
Robust: sets different hysteresis values for falling and rising edges
to avoid an undefined state of the trigger system. Use this setting
for very noisy signals. For details, see "Robust trig-
ger" on page 61.
SCPI command:
DIGital<m>:THReshold on page 739
BUS<m>:PARallel:THCoupling on page 742
DIGital<m>:HYSTeresis on page 739
Reference for MSO