def relativeTo(task,newval=None):
"""
newval may be either DAQmx_Val_FirstSample 10424
or
DAQmx_Val_CurrWritePos (10430)
"""
if not newval:
val = mx.uInt64(0)
mx.ni.DAQmxGetWriteRelativeTo(task, byref(val))
return val.value
else:
mx.CHK(mx.ni.DAQmxSetWriteRelativeTo(task,newval))
def getCurWritePos(task):
cur_wp = mx.uInt64(0)
mx.CHK(mx.ni.DAQmxGetWriteCurrWritePos(otask, byref(cur_wp)))
return cur_wp.value
# get_regeneration
otask = nidaqmx.AnalogOutputTask()
otask.create_voltage_channel(analog_output_term, min_val=-10.0,max_val=10.0)
otask.configure_timing_sample_clock(source=r'ai/SampleClock',
rate=samplerate,
sample_mode=samplemode,
samples_per_channel=nsamples)
otask.write(outputdata,auto_start=False)
# start them both
cur_wp = mx.uInt64(0)
otask.start()
itask.start()
d1=itask.read(samples_per_channel=500)
time.sleep(1.0)
print "current read position", itask.get_read_current_position()
mx.ni.DAQmxGetWriteCurrWritePos(otask, byref(cur_wp))
otask.write(output2)
after = getCurWritePos(otask)
time.sleep(0.1)
# d2 = itask.read(samples_per_channel=500)
# itask.wait_until_done(10.0)
# print "otask.get_bufsize()",otask.get_bufsize()
print "before cur_wp:",cur_wp.value, "and after:", after
print "relativeTo:", relativeTo(otask)
print "done"
