User`s guide

162 53220A/53230A User’s Guide
5 Triggering and Gating
Again using Table 5-2, if a resolution of 6-digits is required the corresponding
gate time can be located and sent directly as:
SENS:FREQ:GATE:TIME 10e-6 // set gate time = 10 us
External Gate Sources
Gate sources EXTernal, INPut[1], and INPut2 are external sources.
EXTernal is the counter’s rear panel ‘Gate In/Out’ BNC, and INPut[1]/
INPut2 (represented by softkeys Chan 1 and Chan 2) are the counter’s channel
1 and channel 2 inputs.
External Gate Signal Polarity
When using any external gate source the polarity of the gate signal and there-
fore, the duration of the gate, is set or changed with the command:
NOTE
OUTput:STATe OFF must be set when using gate source EXTernal. See
“Enabling Gate Signals on the ‘Gate In/Out BNC” for more information and for
information on using gate signals to synchronize other instruments.