VXI VT1422A - Manual (Page 123)

Programming the VT1422A for Data Acquisition and Control 121 Chapter 4
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.