Loic VINET

Hello I am using "digital discovery" connected to a PC or a raspberry. I have a trigger given by a GPS having 100 ms up and 900 ms down. I run the here-include python program (see scriptLV) at a frequency of 5 seconds, and I get the trigger time using the function 'dwf.FDwfDigitalInStatusTime(hdwf, byref(psecUtc), byref(ptick), byref(pticksPerSecond))'. I should have the same time at a millisecond precision, but I have a variation at each iteration and I don't understand why. Time | ms ------------------------------------ 2023-12-12 18:52:58 | 432.076782 2023-12-12 18:53:08 | 432.460197 2023-12-12 18:53:18 | 432.157247 2023-12-12 18:53:28 | 433.663812 2023-12-12 18:53:38 | 436.344122 2023-12-12 18:53:48 | 437.429318 2023-12-12 18:53:58 | 438.901731 2023-12-12 18:54:08 | 440.093428 2023-12-12 18:54:18 | 442.817301 2023-12-12 18:54:28 | 443.583707 What is the explanation? Is it the internal clock of the PC or the Raspberry? Regards scriptLV.py

Hi @attila No I am not driving dio 31 and 12. I have just a wire between 31 and 12. I have a trigger generate by dio 25 to dio 15. When I run the PC windows program I see no data When I run the raspberry program I see data When I disconnect the wire and run the raspberry program I see no data This is very strange...

Hello, I'm using a Digital Discovery with a Raspberry and a Windows PC, and running the same Python program on both computers. I don't have the same acquisition between them. Here is my test: I have DIO out 31 connected to DIO In 12. The program does not emit any custom signals from the dio 31. But with the raspberry, I get data in dio In 12, and I get nothing with the windows PC which is normal, I should have nothing. When I disconnect dio out 31 from dio in 12, the raspberry does not give any data from dio in 12, which is normal. I have no idea what could explain this difference in behavior.

Hi @attila Here is the script. The phenomena only appears when I am using the PPS trigger. scriptLV.py

Hello, I am using a python program in a raspberry connected to a digital Discovery. I generate a trigger every 1 second with a duration of 100 ms. When I visualise the trigger, I always see a peak at the beginning of the plot just before the peak of the trigger. When I am using a trigger at higher frequency with a smaller peak, the peak disappears. Why do I have this phenomena with the PPS?

Hi @attila I found why it did not work. The durationInSeconds in dwf.FDwfDigitalOutRunSet(hdwf, durationInSeconds) was too big. It was 500, with 10 it works

Hi @attila I place the dwf.FDwfDigitalOutConfigure(hdwf, c_int(1)) in the acquire function just after dwf.FDwfDigitalInConfigure(hdwf, c_int(0), c_int(1)) dwf.FDwfDigitalInConfigure(hdwf, c_int(0), c_int(1)) dwf.FDwfDigitalOutConfigure(hdwf, c_int(1)) But it makes no change. if I replace acqmodeRecord by acqmodeSingle, it doesn't work in both cases. The goal is to record signals with a trigger given by the PPS (pulse per second) of the GPS. This PPS is a square signal of 100 ms each second.

Hi @attila What do you mean? I should place FDwfDigitalOutConfigure after FDwfDigitalInConfigure, that's it? Do you have an example?

Hi @attila Here is the python script. I include at the beginning the configuration. The 1st one works (with 1s acquisition), but not the second one (with 0.1s acquisition) Thank you for your help scriptLV.py

I am using a python program in a raspberry connected to a digital Discovery. I have a trigger every 1 second with a duration of 100 ms. I want to make an acquisition of 20 ms or less. The problem, I have, is that when running the function dwf.FDwfDigitalInStatus(hdwf, c_int(1), byref(sts)) give STS = 1, it stays in status armed and there is no acquisition. When the acquisition has a duration of 1 s and more, it works. What should I do to be able to have an acquisition of less than 1s acquisition duration?

Hi Attila Well well well, it works: psecUtc 1679670100 ptick 418708162 pticksPerSecond 800000000 Thank you I will continue my tests with this new feature.

Hi Attila, Thank you for it and for being so fast. I will test it as soon as possible, maybe not as fast as you.

Hi Attila, Fine 2 questions: Do you have any idea when this new software version should be available? By new software, can you confirm you are talking also about the library cdll.dwf on windows or cdll.LoadLibrary("libdwf.so") on linux? This feature is ultimately very important to us 🙂

Hi Attila, I am using the device "Digital Discovery", what should I do or buy to have a 10 ns precision?

Hi Attila Thank you for your answer I run this: while cSamples < nSamples: dwf.FDwfDigitalInStatus(hdwf, c_int(1), byref(sts)) dwf.FDwfDigitalInStatusTime(hdwf, byref(psecUtc), byref(ptick), byref(pticksPerSecond)) For the first iteration I had for example: psecUtc 1679507688 ptick 253 pticksPerSecond 1000 I'm looking for at least 10 ns precision, looks like I have ms precision Is it possible to get that 10 ns precision? another question, does it give me the time of the first item of the acquisition at the first iteration?