# Can't access/write to USB Flash attached to RT-Box 1 on TSP 4.0

**URL:** https://forum.plexim.com/t/cant-access-write-to-usb-flash-attached-to-rt-box-1-on-tsp-4-0/2924
**Category:** RT Box
**Created:** [March 17, 2026, 11:15am UTC](https://forum.plexim.com/t/cant-access-write-to-usb-flash-attached-to-rt-box-1-on-tsp-4-0/2924 "2026-03-17T11:15:30Z")
**Posts on this page:** 4
**Page:** 1

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### Author: ![Sayeed1997](https://avatars.discourse-cdn.com/v4/letter/s/bbe5ce/32.png) [@Sayeed1997](https://forum.plexim.com/u/Sayeed1997)
#### Post date: [March 17, 2026, 11:15am UTC](https://forum.plexim.com/t/cant-access-write-to-usb-flash-attached-to-rt-box-1-on-tsp-4-0/2924/1 "2026-03-17T11:15:30Z")

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Hi,

I updated to PLECS standalone 5.0, and it required me to update the firmware of RT Box 1 to 4.0. Then I load my model(that has a write to storage block) to the RT Box, and I am getting following errors.

\* CPU PWM sample time: 3.75 ns  
\* ADC acquisition period: 100.00 µs  
\* DAC update period: 100.00 µs  
\* CPU base step size: 100.00 µs  
Starting simulation. Error while opening file ‘/run/media/sda1/test\_rt2\_0001/data.csv’ for writing: No such file or directory.

Even WebDAV does not show the usb drive or the files in the directory.

I had to revert back to TSP v3.18 and standalone v4.9.x.

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### Author: ![Oliver\_Schwartz](https://dub1.discourse-cdn.com/flex006/user_avatar/forum.plexim.com/oliver_schwartz/32/6_2.png) [@Oliver\_Schwartz](https://forum.plexim.com/u/Oliver_Schwartz)
#### Post date: [March 17, 2026, 12:42pm UTC](https://forum.plexim.com/t/cant-access-write-to-usb-flash-attached-to-rt-box-1-on-tsp-4-0/2924/2 "2026-03-17T12:42:10Z")

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This is indeed a bug in the current TSP, thank you for reporting this. We’ll fix it with TSP release 4.0.4.

For what it’s worth, you can still use PLECS standalone 5.0 with TSP 3.1.8.

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<div class="post-metadata">

### Author: ![Sayeed1997](https://avatars.discourse-cdn.com/v4/letter/s/bbe5ce/32.png) [@Sayeed1997](https://forum.plexim.com/u/Sayeed1997)
#### Post date: [March 17, 2026, 3:26pm UTC](https://forum.plexim.com/t/cant-access-write-to-usb-flash-attached-to-rt-box-1-on-tsp-4-0/2924/3 "2026-03-17T15:26:59Z")

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Thanks. I ran the model in PLECS 4.9.9 and TSP 3.1.7 and obtained the desired result.

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<div class="post-metadata">

### Author: ![Oliver\_Schwartz](https://dub1.discourse-cdn.com/flex006/user_avatar/forum.plexim.com/oliver_schwartz/32/6_2.png) [@Oliver\_Schwartz](https://forum.plexim.com/u/Oliver_Schwartz)
#### Post date: [March 27, 2026, 3:15pm UTC](https://forum.plexim.com/t/cant-access-write-to-usb-flash-attached-to-rt-box-1-on-tsp-4-0/2924/4 "2026-03-27T15:15:41Z")

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TSP 4.0.4 with a fix for this issue has now been released.