Specifications

7-16
Softkey Menu Descriptions
Trigger & Setup Menu
Enables the entry of the value for the subrate clock high output
level in units of volts or millivolts.
Sets the subrate clock outputs to use emitter coupled logic
levels. It also resets the Clock Amplitude and Clock Hi-Level to
default values.(Clock Amplitude +500 mV; Clock Hi-Level 0V)
Trigger & Setup Menu
Path
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Description
The softkey enables a menu of softkeys which allow the user to:
• Configure the pattern generator trigger output
• Configure the error detector trigger output
• Configure the error detector's Error Output pulse type (RZ or stretched)
• Save the entire instrument configuration in one of ten USER SETUPS.
• Recall an entire instrument configuration from one of ten USER SETUPS or two
PRESETS.
Pattern Generator Trigger Output
The Pattern Generator Trigger Output produces a 16 clock-period trigger pulse (except
alternate word) which is either synchronized to the pattern (PATTERN mode) or is the
input clock divided by 32 or 8. In PATTERN mode the trigger pattern that the user has
entered is matched to the pattern being generated and a trigger pulse is produced when the
two correspond. For a 2^n−1 pattern the length of the trigger pattern is n bits, which
ensures that the pattern will be unique. The pulse repetition rate is 1 pulse/32 pattern
repetitions.
When a zero-substitution PRBS, a mark-density PRBS or a user-defined pattern is
selected, then the trigger pattern is selectable with the softkey. It can be
set anywhere within the pattern. Trigger pulse occurs at lowest common multiple of 256
and pattern length.
When an alternate pattern is selected, the user can select between a trigger pulse
synchronized to the signal at the AUXILIARY INPUT or one pulse per pattern.
Toggles between PATTERN mode, in which the occurrence of a
user-entered pattern in the output stream, is the condition which
S/R DAT HI-LEVL
S/R DAT ECL
trigger & setup MENU
trigger & setup
trigger & setup
PG TRIG BIT
PG TRIG PAT CLK