VXI VT1538A user manual Variable Frequency Fixed Width Pulse Train FM

Variable Frequency Fixed Width Pulse Train (FM)

This means that the E1538 outputs a continuous train of pulses whose frequency is controlled by the algorithm. The logic 1 level pulse width is set by a SCPI command before INIT. Use the following command sequence:

SOURce:FUNCtion:PULSe (@<ch_list>) to enable pulse generation. SOURce:FM[:STATe] ON,(@<ch_list>) to select the FM mode. SOURce:PULSe:WIDTh <width>,(@<ch_list>) to pre-set the pulse width of the logic 1 portion of the waveform. <width> can range from 7.87μSec to 7.812mSec.

The frequency value sent by the algorithm can range from 128Hz to 40KHz.

	2
	fout
The frequency resolution is	4.194 MHz
	---------------------------

To configure channel 45 to output variable frequency continuous train with fixed pulse width

SOUR:FUNC:PULS (@145)	channel sources pulses...
SOUR:FM ON,(@145)	and continuous pulse train
SOUR:PULS:WIDT .001,(@145)	1 msec fixed pulse width

The algorithm can now output a frequency value to channel 45:

O145 = 250 /* channel 45 will source 250 Hz pulse train */

Figure 18. Output Fixed Pulse Width Variable Frequency (FM)

Agilent E1538A Enhanced Frequency/Totalize/PWM SCP 27