Tektronix CSA8000B - Manual (Page 116)

Triggering
3- 42 CSA8000B & TDS8000B User Manual
Trigger Sources. The trigger source provides the signal that the trigger system
monitors. The source can be:
H the internal clock of the instrument (TDR clock rate), with user-selectable
clock frequencies. The Internal Clock Out connector supplies a replica of the
internal clock at the instrument front panel. See Figure 3--13 on page 3--42.
H an external signal coupled to one of the trigger input connectors (see
Figure 3--13) on the front panel:
H External Direct, DC coupled and usable with signals up to at least
3.0 GHz
H External Prescale, divided by 8 and usable with signals up to at least
12.5 GHz
NOTE. The upper limit is determined by signal input level; this is enhanced by
the optional accessory 80A01.
H an internal clock-recovery trigger provided by an optical sampling module
equipped with a clock-recovery option. Clock recovery is user-selectable for
triggering rates that depend on the sampling module used; for example,
either 622 Mbps (OC-12/STM-4 standards) or 2.488 Gbps (OC-48/STM-16
standards) for the 80C01-CR Optical Sampling Module.
Some optical sampling modules support continuous-rate clock recovery. If
you have such a module installed, a user-defined custom clock recovery rate
is selectable from the Trigger Source Setup menu.
Trigger
prescale
input
Trigger
direct
input
Trigger
probe
power
Internal clock output
Figure 3- 13: Trigger inputs