LJH

Hello, I am trying to use the FDwfAnalogInTriggerSourceSet to set my trigger. I am sending a signal from the wavegen out directly to the channel 1 input and reading. I set my signal to send out 1V at 500ms but I can see from the plots I am actually reading my signal at 510ms ~520ms. I have included my code below as well as a plot of what the digilent is seeing. If I send in different amplitudes, the delay changes around a bit as well: 2V input: 0.1V input: please let me know if I can remedy this! Thank you! - LJH channel calibration.py

Hi, I had a quick follow up question about offsets. I am looking to offset my read signals by using the FDwfAnalogInChannelOffsetSet() function, but it seems that the offset does not express itself. I have included an example below: I am looking for the generated signal to be read 1V higher ( starting at 1V and ending at 3V). I did use FDwfAnalogOutNodeOffsetSet() with success, but the application I am using is reading the signal in only. I also noted that in this post there is mention that "If you want to offset the values compared to the input signal then do it in your application, foreach sample[i] = sample[i] + off". Would this be the only way I can offset the read values? Thank you! Arbitrary Atilla.py

Thank you so much Attila, this was exactly what I was trying to do!

Hello, I am using a Digilent Analog Discovery Pro and trying to interface with it using python. I am able to run some examples, but I am having some trouble running the AnalogOut_pattern.py code as I cannot seem to output the custom pattern just once. My goal is to input a custom signal and be able to record the signal. I used a combination of the analogIn_record.py sample and analogOut_pattern.py sample to create the code below. However, I just want the pattern to play once, not tile 20 times. """ DWF Python Example Author: Digilent, Inc. Revision: 2018-07-19 Requires: Python 2.7, 3 """ from ctypes import * from dwfconstants import * import math import time import matplotlib.pyplot as plt import sys import numpy if sys.platform.startswith("win"): dwf = cdll.dwf elif sys.platform.startswith("darwin"): dwf = cdll.LoadLibrary("/Library/Frameworks/dwf.framework/dwf") else: dwf = cdll.LoadLibrary("libdwf.so") #declare ctype variables hdwf = c_int() sts = c_byte() hzAcq = c_double(100000) nSamples = 200000 rgdSamples = (c_double*nSamples)() cAvailable = c_int() cLost = c_int() cCorrupted = c_int() fLost = 0 fCorrupted = 0 #print(DWF version version = create_string_buffer(16) dwf.FDwfGetVersion(version) print("DWF Version: "+str(version.value)) #open device print("Opening first device") dwf.FDwfDeviceOpen(c_int(-1), byref(hdwf)) if hdwf.value == hdwfNone.value: szerr = create_string_buffer(512) dwf.FDwfGetLastErrorMsg(szerr) print(str(szerr.value)) print("failed to open device") quit() ############################################################## bSamples = 1000 rgdSamples1 = (c_double*bSamples)() for i in range(0,bSamples): if i % 2 == 0: rgdSamples1[i] = 0; else: rgdSamples1[i] = 1.0*i/bSamples; print("Generating wave...") dwf.FDwfAnalogOutNodeEnableSet(hdwf, c_int(0), AnalogOutNodeCarrier, c_bool(True)) dwf.FDwfAnalogOutNodeFunctionSet(hdwf, c_int(0), AnalogOutNodeCarrier, funcPlay) dwf.FDwfAnalogOutDataSet(hdwf, c_int(0), rgdSamples1, 100) dwf.FDwfAnalogOutNodeFrequencySet(hdwf, c_int(0), AnalogOutNodeCarrier, c_double(1000)) dwf.FDwfAnalogOutNodeAmplitudeSet(hdwf, c_int(0), AnalogOutNodeCarrier, c_double(5)) dwf.FDwfAnalogOutRunSet(hdwf, c_int(0), c_double(0.01)) # run for 10ms dwf.FDwfAnalogOutRepeatSet(hdwf, c_int(0), c_int(1)) # repeat once dwf.FDwfAnalogOutConfigure(hdwf, c_int(0), c_bool(True)) plt.plot(numpy.fromiter(rgdSamples1, dtype = float)) plt.show() ################################################################### #set up acquisition dwf.FDwfAnalogInChannelEnableSet(hdwf, c_int(0), c_bool(True)) dwf.FDwfAnalogInChannelRangeSet(hdwf, c_int(0), c_double(5)) dwf.FDwfAnalogInAcquisitionModeSet(hdwf, acqmodeRecord) dwf.FDwfAnalogInFrequencySet(hdwf, hzAcq) dwf.FDwfAnalogInRecordLengthSet(hdwf, c_double(nSamples/hzAcq.value)) # -1 infinite record length #wait at least 2 seconds for the offset to stabilize time.sleep(2) print("Starting oscilloscope") dwf.FDwfAnalogInConfigure(hdwf, c_int(0), c_int(1)) cSamples = 0 while cSamples < nSamples: dwf.FDwfAnalogInStatus(hdwf, c_int(1), byref(sts)) if cSamples == 0 and (sts == DwfStateConfig or sts == DwfStatePrefill or sts == DwfStateArmed) : # Acquisition not yet started. continue dwf.FDwfAnalogInStatusRecord(hdwf, byref(cAvailable), byref(cLost), byref(cCorrupted)) cSamples += cLost.value if cLost.value : fLost = 1 if cCorrupted.value : fCorrupted = 1 if cAvailable.value==0 : continue if cSamples+cAvailable.value > nSamples : cAvailable = c_int(nSamples-cSamples) dwf.FDwfAnalogInStatusData(hdwf, c_int(0), byref(rgdSamples, sizeof(c_double)*cSamples), cAvailable) # get channel 1 data #dwf.FDwfAnalogInStatusData(hdwf, c_int(1), byref(rgdSamples, sizeof(c_double)*cSamples), cAvailable) # get channel 2 data cSamples += cAvailable.value dwf.FDwfAnalogOutReset(hdwf, c_int(0)) dwf.FDwfDeviceCloseAll() print("Recording done") if fLost: print("Samples were lost! Reduce frequency") if fCorrupted: print("Samples could be corrupted! Reduce frequency") f = open("record.csv", "w") for v in rgdSamples: f.write("%s\n" % v) f.close() plt.plot(numpy.fromiter(rgdSamples, dtype = float)) plt.show() print(len(numpy.fromiter(rgdSamples, dtype = float))) Thank you! -LJH