Reset once and multiple 32768 patterns

[laurent]

Hi,

I am writing a python script to output patterns on my digital discovery.

I need to have a reset at 0 during 100ns on DIO24=channel 0, then 20000pattern that are repeated. But I do not want to repeat the reset. I have tried many commands of the SDK ref manual, including

 Reset = 0

dwf.FDwfDigitalOutRepeatTriggerSet(hdwf,  c_int(Resetn), c_int(1)) # repeat = false

But, no way the reset is always repeated. How to proceed ?

BRgds,

Laurent

[attila]

Hi @laurent

Such pulses can be generated specifying count zero and count-init nonzero.

See the example script: DigitalOut_ResetPattern.py

# DIO-0 or DIO-24 on Digital Discovery
# generate 100ns high pulse after start/init then remain low, since low count is nonzero and high is zero
dwf.FDwfDigitalOutEnableSet(hdwf, c_int(0), c_int(1))
dwf.FDwfDigitalOutIdleSet(hdwf, c_int(0), DwfDigitalOutIdleLow) # DwfDigitalOutIdleLow = 1
dwf.FDwfDigitalOutDividerSet(hdwf, c_int(0), c_int(int(hzSys.value*100e-9))) # 100ns (10MHz) prescaler
dwf.FDwfDigitalOutCounterInitSet(hdwf, c_int(0), c_int(1), c_int(1)) # start high for 1 count
dwf.FDwfDigitalOutCounterSet(hdwf, c_int(0), c_int(1), c_int(0)) # low = 1 and high = 0

 

 

[laurent]

I tried it with a feedback loop to the inputs (as shown below) to check it, and, with the attached code.

But the output signals remains flat at 0 ...

Laurent

 

DigitalOut_ResetPattern.py

[attila]

Hi @laurent

I have added to the script: trigger, correct sample rate and to capture DIO lines fist, so you don't have to make loopback:

DigitalOut_ResetPattern.py

 

 

[laurent]

Thank you, I just modified the way to plot to understand each signal ...

By the way, how can you get your data back into Waveforms when the pattern is generated with a python script ?

DigitalOut_ResetPattern_LC.py

[attila]

Hi @laurent

With another device.

Only one application can connect to a device at a time, but the DIO signals are bidirectional.
You can generate on some output and capture at the same time the inputs and outputs as well.

[laurent]

How to set the channel to trigger on ?

dwf.FDwfDigitalInTriggerSourceSet(hdwf, c_ubyte(3)) # trigsrcDetectorDigitalIn
dwf.FDwfDigitalInTriggerSet(hdwf, c_int(0), c_int(0), c_int(0x0003), c_int(0x0003))

What c_ubyte(3) refer to ? It seems to be kink to channel 0, how to chenge it if I want to trigger on channel 1 ou 2 ?

Laurent

[attila]

Hi @laurent

The trigger and the received data samples are bit field sets, each value or sample representing a channel:
fs/sample = [bit-0/channel-0] [bit-1/channel-1]...

dwf.FDwfDigitalInTriggerSet(hdwf, c_int(0), c_int(0), c_int(0x0003), c_int(0x0003))
This will trigger on rinsing or falling edge of channel-0 or 1:
0x0003 = (1<<1) | (1<<0) 

In case you use the DIOs first on the Digital Discovery FDwfDigitalInInputOrderSet(hdwf, 1) it will trigger on DIO-24 or 25 otherwise on DIN-0 or 1.

[laurent]

Hi,

I still use the loop between the output and inputs as shown on the pictures above to check my patterns written in Python.
I need to send one burst of signals with a depth of 32101. But, I don't know what to write in the 2 registers dwf.FDwfDigitalOutRunSet() and dwf.FDwfDigitalOutRepeatSet(hdwf, c_int(1)) ?
Whatever I set in these commands, the pattern is repeated. I guess it is due to the fact I read them back, but is there a way to check that are not repeated ?
Here are the plotted result and the python script I use - the configuration is above in the photo.

BRgds,
Laurent

 

OTP_digital_HV1.py

[attila]

Hi @laurent

You should apply the run/repeat settings before starting the output, just like the other options.
The run time should be expressed in seconds.
 

[laurent]

Hi Attila,

I spend a week to try to generate the following signals, but I still cannot rise the signals at different times. I tried with 2 methods : pulses and arbitrary pattern, but none of them gave me successful result. I know that the timing are not good, because I was trying to get the right pattern at first. I don't know how to a rising edge at a different time for my 2 signals. I already spend several days on it using the waveforms_sdk_rm.pdf

BRgds,

Laurent

 

 

OTP_digital_HV2.py OTP_digital_HV1.py

[attila]

Hi @laurent

The default idle output (when not running) is initial value. Your HV patterns starts with 1.
Use this to have idle output 0:
dwf.FDwfDigitalOutIdleSet(hdwf, c_int(HV), c_int(1)) # DwfDigitalOutIdleLow

In order to generate the above signal you should have more 1s in your Prog pattern.

In order to have sample rate at 1MHz use:
dwf.FDwfDigitalOutDividerSet(hdwf, c_int(HV), c_int(100)) # set sample rate
dwf.FDwfDigitalOutDividerSet(hdwf, c_int(Prog), c_int(100)) # set sample rate

HV [1, 1, ... 32032‬ zeros]
Prog [18x 0s, 32000x 1s, 16x 0s]

The run length should be:
dwf.FDwfDigitalOutRunSet(hdwf, c_double(6*32034e-6)) 
or:
dwf.FDwfDigitalOutRunSet(hdwf, c_double(32034e-6)) 
dwf.FDwfDigitalOutRepeatSet(hdwf, c_int(6))