Installation guide
ParBERT Overview Getting Started
Agilent 81250 ParBERT Installation Guide, February 2002 21
The ParBERT Approach
It has been mentioned that a single Agilent 81250 system can comprise 
up to three clock modules in a master-slave configuration. Such a 
configuration uses expander frames and has up to three clockgroups or 
up to 33 data generator/analyzer modules.
It has also been mentioned that one mainframe can house several Agilent 
81250 systems. They consist of independent clock modules with 
associated data generator/analyzer modules. Such configurations make it 
possible to test a device under asynchronous conditions using 
independent clock pulses.
The concept of the Agilent 81250 Parallel Bit Error Ratio Tester is to 
create so-called virtual systems from the system’s present hardware 
resources (clock modules, data modules, generator and analyzer 
frontends).
Virtual Systems
The basic (default) system is called DSRA (DSR = digital stimulus and 
response, system A). 
If the hardware comprises several independent clock modules—not 
connected as slaves—then additional systems are available. By default, 
they get ascending names, such as DSRB, DSRC, and so on.
Figure 9 Virtual Systems in One Mainframe
Separate systems are widely used for testing multiplexers or 
demultiplexers. Such devices generally require different clock 
frequencies at the generating and analyzing sides. MUX/DEMUX tests 
can be performed by one system, if the ratio of these frequencies is 2
n
, 
such as 2, 4, 8, 16, and so on. If it is not, separate data generating and data 
analyzing systems will do the job.
DSRCDSRA DSRB
Clock modules










