LeCroy WaveJet 300A series

Getting Started Manual
WJ-A-GS-E Rev A 45
Pulse Count Triggering
Source lets you choose a channel input or an external input.
Select positive or negative polarity.
Coupling modes comprise AC, DC, HF Reject, and LF
Reject
Select No. of Pulse to set the number of pulses to count
before the scope triggers.