VXi VT1529A/B Benutzerhandbuch

Programming the VT1422A for Data Acquisition and Control 121

Variable Width Pulses at Fixed Frequency (PWM)

This function sets up one or more VT1534A/38A channels to output a train
of pulses. A companion command sets the period for the complete pulse
(

↑

edge to

↑

edge). This of course fixes the frequency of the pulse train.

The width of the pulses from these channels is controlled by Algorithm
Language statements.

Use the command SOURce:FUNCtion[:SHAPe]:PULSe (@<ch_list>).
Example command sequence:

Enable pulse width modulation for VT1534A’s first channel at SCP position 4

SOUR:PULM:STATE ON,(@132)

To set pulse period to 0.5 ms (which sets the signal frequency 2 kHz)

SOUR:PULSE:PERIOD 0.5e-3,(@132)

To set function of VT1534A’s first channel in SCP position 4 to PULSE

SOUR:FUNCTION:PULSE (@132)

Example algorithm statement to control pulse width to 0.1 ms (20% duty-cycle)

O132 = 0.1e-3;

Fixed Width Pulses at Variable Frequency (FM)

This function sets up one or more VT1534A/38A channels to output a train
of pulses. A companion command sets the width (

↑

edge to

↓

edge) of the

pulses. The frequency of the pulse train from these channels is controlled by
Algorithm Language statements.

Use the command SOURce:FUNCtion[:SHAPe]:PULSe (@<ch_list>).
Example command sequence:

Enable frequency modulation for VT1534A’s second channel at SCP position 4

SOUR:FM:STATE ON,(@133)

To set pulse width to 0.3333 ms

SOUR:PULSE:WIDTH 0.3333e-3,(@133)

To set function of VT1534A’s second channel in SCP position 4 to PULSE

SOUR:FUNCTION:PULSE (@133)

Example algorithm statement to control frequency to 1000 Hz

O133 = 1000;

Variable Frequency Square-Wave Output (FM)

To set function of VT1534A/38A’s third channel in SCP position 4 to output a
variable frequency square-wave.

SOUR:FUNCTION:SQUare (@134)

Example Algorithm Language statement to set output to 20 kHz

O134 = 20e3;

Note: For complete VT1534/38A capabilities, see the SCP’s User’s Manual.