B&K 4070A Manual Do Utilizador

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BK Precision 4070A User Manual Rev.2.2 
24 
5.11  Burst Mode 
Introduction 
   The Burst mode generates a sinusoid burst of fixed frequency and level for a specified duration. Both continuous 
and triggered bursts may be generated.  
   In the continuous burst mode, the 4070A continuously gates the output sinusoid on and off according to the values 
entered in the On and Off fields.  
   In triggered burst mode, the output frequency is set to 0 Hz and the unit awaits a trigger condition. When a trigger 
condition occurs, the 4070A delays for a time specified in the Off time field and then sets the output frequency to 
the specified value.  When the time specified in the On field has elapsed, the 4070A resets the output frequency to 0 
Hz and awaits another trigger condition.  
   The 4070A will simultaneously accept a trigger from all of the above sources.:  
 
1. Pressing the Trigger key  
 
2. Applying a low-to-high transition on the Ext Trig In connector  
 
3. Sending an ASCII "T" to the RS-232 port  
   NOTE: An external digital signal can be used to generate bursts by switching to Sinewave mode and using the Ext. 
Gating In connector to gate the output waveform on or off. The output is turned off when the input is at a logic high 
voltage (3V to 10V). This input can be run up to 3 MHz. 
Figure 5.11-1: Burst mode display 
1. Continuous / Triggered Mode  
   This field selects whether the bursts will be generated on ongoing or s ingle event basis. To select Triggered mode, 
press 0. To select Continuous mode, press 1. Pressing any arrow key or rotating the wheel will toggle this value. 
2. Burst On Time (duration) 
   The burst will last for the duration specified in this field before being switched off. You may enter a value from    
1 mS to 99,999 mS in 1 mS step. 
3. Burst frequency  
   The output frequency is held at this value during the burst. You may enter from 0 Hz (DC) to 21.5 MHz in  
0.01 Hz steps. 
4. Burst Off Time (delay) 
   The burst waveform will be held at 0V for the duration in this field before the sinewave is switched on. In 
triggered burst mode this value may be viewed as a delay between the trigger event and when the output sinusoid is 
generated. You may enter a value from 0 mS to 99,999 mS in 1 mS steps.  
5. Level 
   In this field enter the 50 ?   loaded output level, from 4 mVp -p to 10 Vp -p or from -44.0 dBm to +24.0 dBm.  
Offset    
   You can enter an offset voltage for the output waveform.  For more information on refer to section 4.4.  
Ext Trigger Input
  
   In triggered burst mode this input functions as an external trigger input. A logic low-to-high transition on this 
input will trigger the burst. This input has an internal pull down resistor so that the input is held at a logic low when 
this input is left unconnected. See section 2.0 for more information. 
Burst Mode 
Trig   
   Ton:        10,000 mS 
1,000,000.00 Hz    Off:         0 mS          -10.0 dBm 
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