Agilent Technologies E1441A Gated Burst Mode, Burst Trigger Source For Counted Burst Mode

Gated Burst Mode

There is only one form of the gated burst mode. The burst is controlled by a gating signal that is supplied from an external trigger source. The burst starts when the trigger signal is set to a TTL "high" level. The burst ends when the gating signal returns to a TTL "low" level.

Gated Burst Modulation Output
off period	on period
(gate = 0)	(gate = 1)
Burst Modulation Gating Signal
(selected by TRIG:SOUR
either EXT or TTLTRG<0-7>)
NOTE: TTLT polarity is always
the opposite of the of EXT TRIG

Figure 2-5. Gated Burst Mode

The command sequence to configure this mode is:

APPLy:<shape>		<freq>,<ampl>,<offset>		set up wave form
BM:SOURce	EXTernal		this selects the "gated" mode
TRIG:SOURce		EXTernalTTLTRG<0-7>	trigger from external signal
BM:STATE	ON		AFTER all modulation AND
			trigger selection, enable BMod

Table 2-5shows an overview of the allowable burst mode configurations

Table 2-5. Burst Mode Configurations

	Burst Source	Trigger Source	Burst Count	Burst Rate	Burst Phase
	(BM:SOUR)	TRIG:SOUR	(BM:NCYC)	(BM:INT:RATE)	(BM:PHAS)
Counted Burst Modes	INTernal	INTernal	Available	Available	Available
		EXTernal, BUS,	Available	Not Used	Available
		or TTLTRG<n>
Gated Burst Mode	External	EXTernal or	Not Used	Not Used	Not Used
		TTLTRG<n.>

Burst Trigger Source For Counted Burst Mode

When the burst mode is set to "counted" (BM:SOUR INTernal), a trigger

Chapter 2 Agilent E1441A Application Information 35