# Plugin PWR THD Versus Power: problems **URL:** \ **Category:** QA40x\ **Created:** [October 30, 2022, 5:50am UTC](https://forum.quantasylum.com/t/plugin-pwr-thd-versus-power-problems/751 "2022-10-30T05:50:13Z")\ **Posts on this page:** 9\ **Page:** 1
**Author:** ![Claudio](https://avatars.discourse-cdn.com/v4/letter/c/7cd45c/32.png) [@Claudio](https://forum.quantasylum.com/u/Claudio)\ **Post date:** [October 30, 2022, 5:50am UTC](https://forum.quantasylum.com/t/plugin-pwr-thd-versus-power-problems/751/1 "2022-10-30T05:50:13Z")
Hi @matt. I have noticed that when I start the QA40x software and activate the the Automated Tests “PWR THD versus Output Power”, the first time I launch it, even if I have chosen “Autoset Input Range” option active, it is not activated and the " Full Scale Input" always remains stuck at 0 dBV. This inevitably leads to saturation of the QA403 input with the inevitable interruption of the plugin. Here are 2 screenshots of what happens: ![1a](https://canada1.discourse-cdn.com/flex032/uploads/quantasylum/original/2X/5/5d7af156de707fc33118539553ca9680cc406610.jpeg) ![2a](https://canada1.discourse-cdn.com/flex032/uploads/quantasylum/original/2X/e/ea3ee7cb902b0cad1b0abb049babab1b331feb32.jpeg) But if I, without making any changes, relaunch the Test Plugin a second time, everything works properly, the attenuator is handled regularly and everything ends up OK. All this always happens the first time I launch the plugin: in other words I always have to launch Test Plugin “PWR THD versus Output Power” twice, because the first time it does not handle the attenuator. Here are 2 screenshots of what happens the second time I launch the plugin: ![3a](https://canada1.discourse-cdn.com/flex032/uploads/quantasylum/original/2X/6/6d4919da4a717f93d6faaf30fb247e13b304a4aa.jpeg) ![4a](https://canada1.discourse-cdn.com/flex032/uploads/quantasylum/original/2X/8/83b55b26a23eccd95a6d4e709f05d550156f1b54.jpeg) Am I doing something wrong? Thank you ---
**Author:** ![matt](https://avatars.discourse-cdn.com/v4/letter/m/a6a055/32.png) [@matt](https://forum.quantasylum.com/u/matt)\ **Post date:** [October 31, 2022, 3:17pm UTC](https://forum.quantasylum.com/t/plugin-pwr-thd-versus-power-problems/751/2 "2022-10-31T15:17:10Z")
Hi @Claudio, thanks for the very detailed bug report. I don’t think you are doing anything wrong, but I don’t seem able to reproduce what you are seeing. Can you take a look at this short video and see if I have recreated your example correctly? ---
**Author:** ![Claudio](https://avatars.discourse-cdn.com/v4/letter/c/7cd45c/32.png) [@Claudio](https://forum.quantasylum.com/u/Claudio)\ **Post date:** [October 31, 2022, 3:34pm UTC](https://forum.quantasylum.com/t/plugin-pwr-thd-versus-power-problems/751/3 "2022-10-31T15:34:56Z")
Hi @Matt. Yes what I saw in the video is exactly what I do. Only if I do it the first time as soon as I launch QA0x, the test fails because the attenuator is not handled, if I repeat it right away (after the test has failed) the test completes correctly because the attenuator is handled regularly. ---
**Author:** ![Claudio](https://avatars.discourse-cdn.com/v4/letter/c/7cd45c/32.png) [@Claudio](https://forum.quantasylum.com/u/Claudio)\ **Post date:** [October 31, 2022, 3:48pm UTC](https://forum.quantasylum.com/t/plugin-pwr-thd-versus-power-problems/751/4 "2022-10-31T15:48:16Z")
> [@Claudio](#): > > “PWR THD versus Output Power” Hi @Matt. I just noticed an interesting thing. If I start a different plugin other than “PWR THD versus Output Power” as soon as I launch QA40x, and only then start the “PWR THD versus Output Power” plugin, then the input attenuator is handled and everything ends up normal from the first attempt. ---
**Author:** ![Claudio](https://avatars.discourse-cdn.com/v4/letter/c/7cd45c/32.png) [@Claudio](https://forum.quantasylum.com/u/Claudio)\ **Post date:** [October 31, 2022, 4:07pm UTC](https://forum.quantasylum.com/t/plugin-pwr-thd-versus-power-problems/751/5 "2022-10-31T16:07:50Z")
Hi @Matt. I noticed another thing that seems important to me: the problem always occurs when I load any of my configurations at start-up via “Load Setting”. After loading any configuration, launching the plugin, it fails the first time, whereas if I launch it a second time (but now I don’t load the configuration because QA40x is already configured), everything completes normally. If, on the other hand, I run the plugin when I start QA40x with the last configuration, everything runs smoothly. I hope I have been clear ---
**Author:** ![matt](https://avatars.discourse-cdn.com/v4/letter/m/a6a055/32.png) [@matt](https://forum.quantasylum.com/u/matt)\ **Post date:** [October 31, 2022, 4:42pm UTC](https://forum.quantasylum.com/t/plugin-pwr-thd-versus-power-problems/751/6 "2022-10-31T16:42:55Z")
Hi Claudio, this is a very good clue. Can you please share a configuration that causes the problem? You can send it to the support at quantasylum email address. thanks! ---
**Author:** ![Claudio](https://avatars.discourse-cdn.com/v4/letter/c/7cd45c/32.png) [@Claudio](https://forum.quantasylum.com/u/Claudio)\ **Post date:** [October 31, 2022, 4:59pm UTC](https://forum.quantasylum.com/t/plugin-pwr-thd-versus-power-problems/751/7 "2022-10-31T16:59:05Z")
HI@Matt. Sent by e-mail ---
**Author:** ![passmedien](https://avatars.discourse-cdn.com/v4/letter/p/fbc32d/32.png) [@passmedien](https://forum.quantasylum.com/u/passmedien)\ **Post date:** [June 27, 2023, 1:43pm UTC](https://forum.quantasylum.com/t/plugin-pwr-thd-versus-power-problems/751/8 "2023-06-27T13:43:39Z")
Hi @matt, I have a problem with this plugin. The whole software crash when I set a increment equal or lower then 0,5 dB. With 0,6dB increment it works like expected. Do you have an idea what the problem could be ---
**Author:** ![matt](https://avatars.discourse-cdn.com/v4/letter/m/a6a055/32.png) [@matt](https://forum.quantasylum.com/u/matt)\ **Post date:** [July 1, 2023, 3:24pm UTC](https://forum.quantasylum.com/t/plugin-pwr-thd-versus-power-problems/751/9 "2023-07-01T15:24:19Z")
Hi @passmedien, this should be fixed for the next release. It was code that was rounding the step value, and so 0.6 was rounded up to 1.0 and it completed, but 0.4 was rounded down to 0 and never completed (and appears to hang). I think the next release will be out next week. Thanks very much for reporting.