2
Connectors
81133A - Front Panel Connectors
All signal outputs and inputs
are accessible at the front
panel. These are:
· 2 Output Connectors
for the differential channel
· Trigger Output
· Clock Input
· Start Input
· 1 Delay Control Input
81134A - Front Panel Connectors
All signal outputs and inputs
are accessible at the front
panel. These are:
· 4 Output Connectors
for the 2 differential channels
· Trigger Output
· Clock Input
· Start Input
· 2 Delay Control Inputs for
both of the output channels
Rear Panel Connectors
Remote control interfaces:
GPIB, LAN, USB 2.0 (see also
‘Additional Features’)
Clock Source
Selecting the clock source
determines the origin of the
time base. All other timing
parameters are derived from it.
There are two choices:
Internal
The Clock is derived from the
internal YIG oscillator.
External
The Clock is derived from the
external input. The external
frequency is measured once
and is thereafter used to
maintain the calculated fre-
quency dependant values
including the pulse width or
phase if set to duty cycle
mode or phase mode respec-
tively .
External 10 MHz Reference
A 10 MHz reference clock can
be applied to the clock input.
This clock is used as a refer-
ence for all timing parameters.
Direct Mode (Direct
Internal/Direct External)
The direct modes allow
changes of frequency without
dropouts in the range of 1:2.
This can be used for
applications, where dropouts
would prevent measurement
with reliable results (e.g.: PLL
frequency sweep, micro proces-
sor clock sweep). In both
direct modes, the delay and
deskew of all channels is set
to zero (deskewed at the con-
nectors) and can't be changed.
Square mode, data mode (NRZ
only) and PRBS mode (NRZ
only) are available. In ‘Direct
External’ mode the PLL is
bypassed and the instrument
exactly follows the externally
attached frequency.
Frequency/Period
The main frequency is set for
all channels. The frequency
can also be set as period
length. The frequency range is
15 MHz to 3.35 GHz, equal to
66.6 ns to 298.5 ps period. The
frequency range can also be
further divided individually for
each channel. Available
dividers are 1, 2, 4, 8, 16, 32,
64, 128.
Main Modes
Pulse Pattern Mode
In Pulse Pattern mode, each
channel can be set indepen-
dently to one of the channel
modes described in 'Channel
Modes'.
Burst Mode
Burst mode enables the output
of a burst consisting of data
repeated n times followed by
continuous zero data. It can be
started either by:
· applying a signal at the start
input.
· the start button.
· sending a command through
the remote connections.
Repetitive Burst Mode
This command selects a
repeated burst consisting of
data repeated n times followed
by a pause of p times zeros of
the same length as the data
before the data is repeated.
Channel Modes
The following channel modes
are available, if the instrument
main mode is set to pulse/pat-
tern:
Note: The frequency of each
channel can be optionally
divided by 1, 2, 4, 8, 16, 32,
64, 128.
Square
Generates a square wave
(clock) of fixed width (50%
duty cycle)
Pulse
Generates pulses with selec-
table width or duty cycle.
Data
Generates data in either RZ,
R1 or NRZ format. In RZ and
R1 mode, the pulse width can
be selected as either width or
duty cycle.
PRBS
Generates a selectable PRBS
(Pseudo Random Bit Sequence)
polynomial of either RZ, R1 or
NRZ format. In RZ and R1
mode, the pulse width can be
selected as either width or
duty cycle.