# Issue with CompactLogix 1768-L43 reading tags **URL:** \ **Category:** Ignition\ **Created:** [November 9, 2016, 7:29pm UTC](https://forum.inductiveautomation.com/t/issue-with-compactlogix-1768-l43-reading-tags/12337 "2016-11-09T19:29:14Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![Curlyandshemp](https://avatars.discourse-cdn.com/v4/letter/c/bcef8e/32.png) [@Curlyandshemp](https://forum.inductiveautomation.com/u/Curlyandshemp)\ **Post date:** [November 9, 2016, 7:29pm UTC](https://forum.inductiveautomation.com/t/issue-with-compactlogix-1768-l43-reading-tags/12337/1 "2016-11-09T19:29:14Z")
I am starting a new V7.7.8 project using a Compactlogix 1768-L43 V20 CPU: [attachment=3]2016-11-09 14\_19\_02-VM Automation V3.34 20150529 - VMware Player (Non-commercial use only).png[/attachment] I can browse the PLC for tags: [attachment=2]2016-11-09 14\_20\_25-QS161619 - Ignition Designer.png[/attachment] but the tags show up us NULL in my project: [attachment=1]2016-11-09 14\_22\_12-QS161619 - Ignition Designer.png[/attachment] Tried stopping/starting device and Compactlogix Module, but result is always the same. [attachment=0]2016-11-09 14\_23\_17-Ignition \_ Ignition448.png[/attachment] ---
**Author:** ![Kevin.Herron](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/kevin.herron/32/7259_2.png) [@Kevin.Herron](https://forum.inductiveautomation.com/u/Kevin.Herron)\ **Post date:** [November 9, 2016, 7:38pm UTC](https://forum.inductiveautomation.com/t/issue-with-compactlogix-1768-l43-reading-tags/12337/2 "2016-11-09T19:38:00Z")
I don’t really know for sure what happened yet, but something changed in firmware 20.19. The legacy Logix drivers simply do not function with this firmware version. It’s as if they’ve turned direct memory access off. Right now the only workarounds are to use an earlier firmware version or to use the newer Logix driver and live with the performance hit from not being able to use DMA. ---
**Author:** ![Curlyandshemp](https://avatars.discourse-cdn.com/v4/letter/c/bcef8e/32.png) [@Curlyandshemp](https://forum.inductiveautomation.com/u/Curlyandshemp)\ **Post date:** [November 9, 2016, 7:50pm UTC](https://forum.inductiveautomation.com/t/issue-with-compactlogix-1768-l43-reading-tags/12337/3 "2016-11-09T19:50:47Z")
[quote=“Kevin.Herron”]I don’t really know for sure what happened yet, but something changed in firmware 20.19. The legacy Logix drivers simply do not function with this firmware version. It’s as if they’ve turned direct memory access off. Right now the only workarounds are to use an earlier firmware version or to use the newer Logix driver and live with the performance hit from not being able to use DMA.[/quote] Arrrrrrg not having much luck lately. I will see if I can flash the CPU down to an earlier version of V20 thanks Kevin ---
**Author:** ![Curlyandshemp](https://avatars.discourse-cdn.com/v4/letter/c/bcef8e/32.png) [@Curlyandshemp](https://forum.inductiveautomation.com/u/Curlyandshemp)\ **Post date:** [November 9, 2016, 8:07pm UTC](https://forum.inductiveautomation.com/t/issue-with-compactlogix-1768-l43-reading-tags/12337/4 "2016-11-09T20:07:15Z")
[quote=“Curlyandshemp”][quote=“Kevin.Herron”]I don’t really know for sure what happened yet, but something changed in firmware 20.19. The legacy Logix drivers simply do not function with this firmware version. It’s as if they’ve turned direct memory access off. Right now the only workarounds are to use an earlier firmware version or to use the newer Logix driver and live with the performance hit from not being able to use DMA.[/quote] Arrrrrrg not having much luck lately. I will see if I can flash the CPU down to an earlier version of V20 thanks Kevin[/quote] Flashed down to V20.18 and it works now. Thanks Kevin. [attachment=0]2016-11-09 15\_05\_27-QS161619 - Ignition Designer.png[/attachment]