# Siemens enhanced driver with Tia portal V20 Firmware 4.0 **URL:** \ **Category:** Ignition\ **Created:** [January 8, 2026, 9:11am UTC](https://forum.inductiveautomation.com/t/siemens-enhanced-driver-with-tia-portal-v20-firmware-4-0/113146 "2026-01-08T09:11:12Z")\ **Posts on this page:** 1\ **Showing post:** 2
**Author:** ![David\_Stone](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/david_stone/32/79749_2.png) [@David\_Stone](https://forum.inductiveautomation.com/u/David_Stone)\ **Post date:** [January 8, 2026, 9:21am UTC](https://forum.inductiveautomation.com/t/siemens-enhanced-driver-with-tia-portal-v20-firmware-4-0/113146/2 "2026-01-08T09:21:56Z")
Which v4 firmware are you on? I know there were some earlier ones that were buggy for the upstream connections. > [@\[IGN-13789\] \[null, Bad\_NotConnected("Communication with the data source is defined, but not established, and there is no last known value available."),](https://forum.inductiveautomation.com/t/ign-13789-null-bad-notconnected-communication-with-the-data-source-is-defined-but-not-established-and-there-is-no-last-known-value-available/109125/13): > > If you're on v4.0.0 and upgrading to v4.0.4 doesn't work, let us know in a new thread. Apparently, there is a similar issue in Siemens Firmware v4.0.4, but only applies when multiple connections are being made. I think the original issue in this thread was something different. IIRC, the way that I was able to reproduce the issue described in this thread was to attempt to read from an Instance DataBlock that contained some tags that were inaccessible. I believe it was fixed in v8.3.1, but we did… --- _[View the full topic](https://forum.inductiveautomation.com/t/siemens-enhanced-driver-with-tia-portal-v20-firmware-4-0/113146)._