Keysight 81150A - External Patterns

Appendix
618
7.4.5 External Patterns
Introduction
In some applications a memory or algorithm (PRBS) based pattern
generation cannot cover all the required test patterns. For such applications
(i.e. a protocol exerciser), the 81150A / 81160A can be used to re-time and
re-shape an externally provided data-stream.
Externally provided patterns are being input at the MOD-IN input on the rear
panel of the instrument. The available data rate is limited to 10Mbit/s in this
case.
The externally provided signal is being evaluated against either 1 or 2
adjustable threshold voltages.
Number of Levels
Threshold comparison
Symbol
Level Index
2
Input <= Lower Threshold
0
0
Input > Lower threshold
1
1
3
Input <= Lower Threshold
0
0
Lower Threshold < Input <=
Upper Thres
-
2
Input > Upper threshold
1
1
When using external pattern mode, the incoming pattern must be sampled
by the 81150A / 81160A before it can be processed by the pattern
generation logic. There are two different sampling modes that differ in the
way the 81150A / 81160A chooses the point in time when the value of the
sample is being determined.