National Instruments NI 5401 Benutzerhandbuch

Chapter 2

Function Generator Operation

2-8

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Figure 2-8 shows the essential block diagram of analog waveform 
generation.

Figure 2-8.  Analog Output and SYNC Out Block Diagram

Figure 2-9 shows the timing relationships of the trigger input and 
waveform output. T

d1

 is the pulse width on the trigger signal. T

d2

 is the time 

delay from trigger to output on Arb output. Refer to Appendix A, 

, for more information on these timing parameters.

Figure 2-9.  Waveform and Trigger Timings

You can switch off the analog lowpass filter at any time during waveform generation. 

When you change this setting, the bouncing of electromechanical relays on the NI 5401 
distorts the output signal for about 10 ms.

DAC

Gain
DAC

Pre Amp

Main Amp

Filter

Lowpass

10 dB

Attenuator

Attenuators

Output

Enable

25 

Ω

Arb

Selector

50 

Ω

/75 

Ω

Offset

DAC

12

Clock

Level

DAC

+
-

SYNC

Comparator

50 

Ω

50 

Ω

(63 dB in 1 dB steps)

Trigger Input Signal
(Slope: Positive, TTL)

Waveform Output
(±5 V

pp

into 50

Ω

)

T

d1

T

d2