User`s guide

4System Setting
30 N9340A User’s Guide
Ext Input
Toggles the channel for external input between Ref
and Tr ig. Ref refers to an external 10 MHz reference
signal. Trig refers to an external TTL signal.
Key Access:
[SYS] > {Setting} > {Ext Input}
External Reference (Ref)
Use the external reference function as follows:
1 Input a 10 MHz signal to the EXT TRIG IN/REF IN
connector.
2 Press [SYS] > {Setting} > {Ext Input} > {Ref}
to enable
the external reference signal input.
The analyzer then turns off its internal reference.
External Trigger (Trig)
When an external TTL signal is used for the
triggering function, the analyzer uses the
instruments reference signal as the default.
Use the external trigger function as follows:
1 Press [SYS] > {Setting} > {Ext Input} > {Trig} to enable
the external TTL signal input.
2 Press [SPAN] > {Zero Span} to activate the Trig ger
function.
3 Access the associated softkeys to select the
rising edge (Ext Rise) or the falling edge (Ext Fall)
as the trigger threshold
NOTE
The external Ref and Trig functions cannot be used
simultaneously.
NOTE
The trace will halt in external trigger mode until the trigger
threshold is met or the free run function is activated.