DurandA

Thank you for your help, this solved the issue. I was running WaveForms 2.21.3 but was missing the Adept Linux runtime. I am surprised that it even worked without the package. Device discovery is also much faster now. Thanks @attila!

Hi @attila Unfortunately your solution does not work. The power supply still shuts down during the second FDwfDeviceOpen() for about 1 second. Here is a minimal script to reproduce the issue: from ctypes import * from dwfconstants import * dwf = cdll.LoadLibrary("libdwf.so") hdwf = c_int() dwf.FDwfParamSet(DwfParamOnClose, c_int(0)) dwf.FDwfDeviceOpen(c_int(-1), byref(hdwf)) dwf.FDwfDeviceAutoConfigureSet(hdwf, c_int(0)) dwf.FDwfAnalogIOChannelNodeSet(hdwf, c_int(0), c_int(0), c_double(True)) dwf.FDwfAnalogIOChannelNodeSet(hdwf, c_int(0), c_int(1), c_double(1.15)) dwf.FDwfAnalogIOEnableSet(hdwf, c_int(True)) dwf.FDwfAnalogIOConfigure(hdwf) dwf.FDwfDeviceClose(hdwf) # start over dwf.FDwfParamSet(DwfParamOnClose, c_int(0)) dwf.FDwfDeviceOpen(c_int(-1), byref(hdwf)) # power shut down during ~ 1 sec dwf.FDwfDeviceAutoConfigureSet(hdwf, c_int(0)) dwf.FDwfAnalogIOChannelNodeSet(hdwf, c_int(0), c_int(0), c_double(True)) dwf.FDwfAnalogIOChannelNodeSet(hdwf, c_int(0), c_int(1), c_double(1.15)) dwf.FDwfAnalogIOEnableSet(hdwf, c_int(True)) dwf.FDwfAnalogIOConfigure(hdwf) dwf.FDwfDeviceClose(hdwf) Thank you for your help.

I am trying to automate some tests using different supply voltages. First, I am using dwfcmd to set a voltage during the setup phase: dwfcmd connect analogio channel=1 enable=1 voltage=1.15 masterenable=1 disconnect Then I use a Python script to vary the voltage: from dwfconstants import * dwf = cdll.LoadLibrary("libdwf.so") hdwf = c_int() print("Opening first device") dwf.FDwfDeviceOpen(c_int(-1), byref(hdwf)) if hdwf.value == hdwfNone.value: print("failed to open device") quit() time.sleep(5) dwf.FDwfAnalogIOChannelNodeSet(hdwf, c_int(0), c_int(0), c_double(True)) dwf.FDwfAnalogIOChannelNodeSet(hdwf, c_int(0), c_int(1), c_double(1.20)) dwf.FDwfAnalogIOEnableSet(hdwf, c_int(True)) However, calling FDwfDeviceOpen() disables the power supply. In the example above, I inserted a 5 sec sleep, which means there is no power during more than 5 seconds. How can access the Analog Discovery 2 from Python without disabling the power supply? Edit: I tried to remove disconnect from dwfcmd args and reuse the hdwf handle which just seems to be the enumeration id (always 1 in my case). However, the last line of dwfcmd.cpp is FApi("FDwfDeviceCloseAll", FDwfDeviceCloseAll());. I tried recompiling dwfcmd without this line using "g++ -o dwfcmd_noclose -I/usr/include/digilent/waveforms/ dwfcmd.cpp -ldwf" but once compiled it fails: pure virtual method called terminate called without an active exception Aborted (core dumped) It seems that this error happens whenever FDwfDeviceClose is not called, including outside of dwfcmd.