User`s guide

Remarks
The selected trigger count applies to the trigger source set by the
TRIGger:SOURce command.
a. For the BUS source, the trigger count sets the number of *TRG
commands that will be accepted before returning to the "idle" trigger
state.
b. For the IMMediate source, the trigger count just controls the number of
readings to be taken.
c. For the EXTernal source, the trigger count sets the number of external
pulses that will be accepted before returning to the "idle" trigger state.
You can use the specified trigger count in conjunction with a sample count
(see SAMPle:COUNt command) which selects the number of readings
(samples) the meter will take per trigger. In this case, the total number of
reading returned will be the product of the sample count and trigger count.
Number of Readings = Sample Count x Trigger Count
If more than 50,000 readings for the 34410A, or 1,000,000 readings for
the 34411A/L4411A are to be taken, the data must be read from reading
memory fast enough to avoid a memory overflow. The most recent
readings are preserved. The oldest readings are overwritten in reading
memory if an overflow occurs. No error is generated, but the MEM Ovfl bit
(bit 14) is set in the Questionable Data Register.
A variable trigger count is not available from the front panel. If you set the
trigger count and then go to local (front panel), the meter ignores the
trigger count setting; however, when you return to remote, the trigger
count returns to the previous value you selected.
The CONFigure and MEASure? commands automatically set the trigger
count to 1.
The instrument sets the trigger count to 1 after a Factory Reset (*RST
command) or an Instrument Preset (SYSTem:PRESet command).
It is recommended that all triggered measurements be made using an
appropriate fixed manual range. That is, turn autorange off
(SENSe:<function>:RANGe:AUTO OFF), or set a fixed range using the
SENSe:<function>:RANGe, CONFigure, or MEASure command.