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Entry  10 Mar 2022, Gennaro Tortone, Bug Report, Python ODB watch 
    Reply  16 Mar 2022, Ben Smith, Bug Report, Python ODB watch 
       Reply  21 Mar 2022, Stefan Ritt, Bug Report, Python ODB watch 
Message ID: 2353     Entry time: 10 Mar 2022     Reply to this: 2356
Author: Gennaro Tortone 
Topic: Bug Report 
Subject: Python ODB watch 
Hi,

I have an issue with ODB watch on MIDAS Python library;

I wrote a simple frontend that read/write FPGA registers through 
ODB keys (simplified version at link below):

https://gist.github.com/gtortone/cd035a9ac4ea7a78ea9cd931e80e2c75

Everything works fine but there is a boolean array
in Settings (Enable ADC sampling) that I need to "toggle" 
(19 bit to 0 and 19 bit to 1). This operation is handled by
detailed_settings_changed_func that write the value of
toggled bit to FPGA.

The issue is that if I quickly toggle the boolean array by
odbedit:

set "/Equipment/odbtest/Settings/Enable ADC sampling[0-18]" 0
set "/Equipment/odbtest/Settings/Enable ADC sampling[0-18]" 1

I see in the Python script the following list of callbacks:

detailed_settings_changed_func: /Equipment/odbtest/Settings/Enable ADC sampling[0] - new value 0
detailed_settings_changed_func: /Equipment/odbtest/Settings/Enable ADC sampling[1] - new value 0
detailed_settings_changed_func: /Equipment/odbtest/Settings/Enable ADC sampling[2] - new value 0
detailed_settings_changed_func: /Equipment/odbtest/Settings/Enable ADC sampling[3] - new value 0
detailed_settings_changed_func: /Equipment/odbtest/Settings/Enable ADC sampling[4] - new value 0
detailed_settings_changed_func: /Equipment/odbtest/Settings/Enable ADC sampling[5] - new value 0
detailed_settings_changed_func: /Equipment/odbtest/Settings/Enable ADC sampling[6] - new value 0
detailed_settings_changed_func: /Equipment/odbtest/Settings/Enable ADC sampling[7] - new value 0
detailed_settings_changed_func: /Equipment/odbtest/Settings/Enable ADC sampling[8] - new value 1    ***
detailed_settings_changed_func: /Equipment/odbtest/Settings/Enable ADC sampling[9] - new value 1
detailed_settings_changed_func: /Equipment/odbtest/Settings/Enable ADC sampling[10] - new value 1
detailed_settings_changed_func: /Equipment/odbtest/Settings/Enable ADC sampling[11] - new value 1
detailed_settings_changed_func: /Equipment/odbtest/Settings/Enable ADC sampling[12] - new value 1
detailed_settings_changed_func: /Equipment/odbtest/Settings/Enable ADC sampling[13] - new value 1
detailed_settings_changed_func: /Equipment/odbtest/Settings/Enable ADC sampling[14] - new value 1
detailed_settings_changed_func: /Equipment/odbtest/Settings/Enable ADC sampling[15] - new value 1
detailed_settings_changed_func: /Equipment/odbtest/Settings/Enable ADC sampling[16] - new value 1
detailed_settings_changed_func: /Equipment/odbtest/Settings/Enable ADC sampling[17] - new value 1
detailed_settings_changed_func: /Equipment/odbtest/Settings/Enable ADC sampling[18] - new value 1
detailed_settings_changed_func: /Equipment/odbtest/Settings/Enable ADC sampling[0] - new value 1
detailed_settings_changed_func: /Equipment/odbtest/Settings/Enable ADC sampling[1] - new value 1
detailed_settings_changed_func: /Equipment/odbtest/Settings/Enable ADC sampling[2] - new value 1
detailed_settings_changed_func: /Equipment/odbtest/Settings/Enable ADC sampling[3] - new value 1
detailed_settings_changed_func: /Equipment/odbtest/Settings/Enable ADC sampling[4] - new value 1
detailed_settings_changed_func: /Equipment/odbtest/Settings/Enable ADC sampling[5] - new value 1
detailed_settings_changed_func: /Equipment/odbtest/Settings/Enable ADC sampling[6] - new value 1
detailed_settings_changed_func: /Equipment/odbtest/Settings/Enable ADC sampling[7] - new value 1
detailed_settings_changed_func: /Equipment/odbtest/Settings/Enable ADC sampling[8] - new value 1
detailed_settings_changed_func: /Equipment/odbtest/Settings/Enable ADC sampling[9] - new value 1
detailed_settings_changed_func: /Equipment/odbtest/Settings/Enable ADC sampling[10] - new value 1
detailed_settings_changed_func: /Equipment/odbtest/Settings/Enable ADC sampling[11] - new value 1
detailed_settings_changed_func: /Equipment/odbtest/Settings/Enable ADC sampling[12] - new value 1
detailed_settings_changed_func: /Equipment/odbtest/Settings/Enable ADC sampling[13] - new value 1
detailed_settings_changed_func: /Equipment/odbtest/Settings/Enable ADC sampling[14] - new value 1
detailed_settings_changed_func: /Equipment/odbtest/Settings/Enable ADC sampling[15] - new value 1
detailed_settings_changed_func: /Equipment/odbtest/Settings/Enable ADC sampling[16] - new value 1
detailed_settings_changed_func: /Equipment/odbtest/Settings/Enable ADC sampling[17] - new value 1
detailed_settings_changed_func: /Equipment/odbtest/Settings/Enable ADC sampling[18] - new value 1

It seems that the second write operation "overlaps" the first one...

The same behavior is not observed using a 'watch' in odbedit...

I can overcame this problem using the value of register as ODB key to avoid 
array of boolean... but I report this issue as "possible" bug/limitation on Python ODB watch;

Cheers,
Gennaro
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