Oswin

I'm using the `uldaq` Python library with a USB-CTR04 device. Whenever I call the `get_pulse_out_status` method, it always gives me `TmrStatus.RUNNING`, regardless of the actual state of the timer. Python 3.10.6 (main, May 29 2023, 11:10:38) [GCC 11.3.0] on linux Type "help", "copyright", "credits" or "license" for more information. >>> import uldaq >>> devices = uldaq.get_daq_device_inventory(uldaq.InterfaceType.USB) >>> daq = uldaq.DaqDevice(devices[0]) >>> daq.connect() >>> tmr.get_pulse_out_status(0) <TmrStatus.RUNNING: 1> >>> tmr.pulse_out_stop(0) >>> tmr.get_pulse_out_status(0) <TmrStatus.RUNNING: 1> >>> tmr.pulse_out_start(0, 100, 0.5, 0, 0.0, uldaq.TmrIdleState.LOW, uldaq.PulseOutOption.DEFAULT) (100.0, 0.5, 0.0) >>> tmr.get_pulse_out_status(0) <TmrStatus.RUNNING: 1> >>> tmr.pulse_out_stop(0) >>> tmr.get_pulse_out_status(0) <TmrStatus.RUNNING: 1> I believe this is a bug. The method should return `TmrStatus.IDLE` when the pulses have ceased. P. S. Issue raised on Github as well: https://github.com/mccdaq/uldaq/issues/56

Hi Fausto, Thanks for this clarification. Understood that triggering is not possible with timers on the USB-CTR boards. That helps. However, that does not completely answer my question. My main inquiry is whether there is ANY way to repeat a timer's output every X us? The concept of triggering was just an example of a way that might achieve that. Now that I know triggering is not possible, is there any other way to do this? As a reminder, here's an illustration of what I am seeking to accomplish: Many thanks, Oswin Rodrigues

Putting my DM conversation with an engineer over here as an update to this:

Hi, I am interfacing with the USB-CTR04 board using the uldaq Python library. I have two desired outcomes: To drive two timers in sync with identical pulse waveforms To time the start of these pulses with microsecond accuracy Here's an example of what I mean: every 100 us, I would like TMR0 and TMR1 to both generate 50 pulses at 100 kHz with 50% duty cycle. However, I face difficulties with executing this level of control using the Python library. Specifically, in order of the objectives: 1. Driving Timers In Sync pulse_out_start method only accepts one timer ID. I have to call it separately, once for each timer, like this: for id in TIMER_IDS: timer.pulse_out_start(id, ...) This results in a delay of about 5-7 ms between when the two timers start their pulse waveforms. I was able to work around this by using the initial_delay argument for the first timer. I gave it a value of 0.007 s, which caused the waveforms to align within 1 us. This works, but I'm wondering if there's a better, more correct way to do this i.e. a way that I can command the board to drive both timers simultaneously. 2. Timing Commands With Microsecond Accuracy Python's time.sleep() method does not work at resolutions of microseconds. I tried the following: while True: start_both_timers() time.sleep(0.0001) # Sleep for 100 us But the measured spacing between consecutive waveforms is around 14 ms, not 100 us. This has to do with how time.sleep() works and the accuracy of the clock that drives it. I'm wondering what's the correct way to do this. Maybe I can use a third timer, say TMR2, to run at 10 kHz (100 us) and somehow use its rising edge as a trigger for the other two timers? I see there is a set_trigger method for timers, however the linked API reference only says to specify the trigger type e.g. POS_EDGE and to use RETRIGGER (for my case) in pulse_out_start. It does not say how to specify TMR2 as the trigger source. I'd love to know how to use triggers with timers, since there are no examples for this in the library. Thank you for your time. If I can get help with only one thing, I would say the second issue is more important. I have an acceptable workaround for the first one. Cheers, Oswin Rodrigues