Vernier LabPro - Manual (Page 69)

Revision Date: 08/02/02
LabPro Technical Manual 69
Syntax: {401, waveform, amplitude, offset, period}
Parameter List: (note: all parameters are mandatory)
waveform
– indicates which waveforms will be generated. The possible values are
waveform Description
0 OFF
1 DC Output
2 Ramp Up (Sawtooth)
3 Ramp Down (Sawtooth)
4 Triangle
5 Square
6 Sine
amplitude – indicates which height of the wave. The possible values are from 0 to 4095.
See Sine examples for exceptions.
offset – indicates where the wave will be centered. The possible values are from 0 to 4095.
period – indicates how often (in milliseconds) the waveform will repeat itself. The number must be
an integer between 5 and 2000. As a result, the range of possible frequencies is 0.5 Hz to
200 Hz.
Return values: No information is returned. However, the output voltage will be produced as
follows:
V
out
= 0.0024*amplitude – 0.0012*offset where the result must satisfy –3V < Vout < 3V
Example 1:.
Computer
Calculator
s{} :Send({})
Examples:
DC Voltage: The easiest way to produce a DC output is usually to control the amplitude and set the offset
to 0 for positive values and control the offset and set amplitude to 0 for negative output values.
401,1,1023,0,0 Vout = 2.5V signal.
401,1,0,2048,0 Vout = –2.5V signal
401,1,1023,1023,0 Vout = 1.25 V signal
Ramp:
401,2,2048,2048,10 Vout = 100Hz ramp up pk-pk = 5V centered about 0
( pk voltage = 2*2048*1.2mV – 2048*1.2mV)
401,3,1023,0,20 Vout = 50Hz ramp down pk-pk = 2.5V centered about 1.25V
Sine
401,6,0,3072,10 Vout = 100Hz Sine wave pk-pk = 8V centered about 0
(pk voltage = 2*3072*1.2mV – 3072*1.2mV)
401,6,1,1536,10 Vout = 100Hz Sine wave pk-pk = 4V centered about 0
401,6,2,768,10 Vout = 100Hz Sine wave pk-pk = 1V centered about 0
NOTE: Sine wave may be improved by adding a low pass filter to output.
Turn off Analog Out:
401,0,0,0,0 NOTE: MUST PASS ALL PARAMETERS