Resolving S7-1200 Firmware Download Denied on Siemens Support

Problem: S7-1200 Firmware Download Denied on Siemens Support

Engineers maintaining SIMATIC S7-1200 fleets frequently encounter a hard stop on the Siemens Industry Online Support portal: a firmware or PLCSIM update returns "Download denied / access restricted", the file cannot be selected, and a manual export-control / anti-automation review is initiated. The portal responds with a verification email or a request to submit a Siemens Support Request, after which the file becomes available.

This denial is not a license problem in the strict sense and not a TIA Portal compatibility problem. It is a portal-side workflow that affects restricted downloads such as PLCSIM V15.1 update packages, newer CPU firmware blobs, and any add-on tagged for export review. The article below walks through the root cause, the compatibility gap that drives the request (PLCSIM V15.1 vs. S7-1200 firmware 4.3), and the four working paths to obtain and deploy the update.

Affected Components and Versions

The specific artifact in the original report is the PLCSIM V15.1 update referenced in Siemens document 109764220 - Updates for PLCSIM V15.1. The file is classified as restricted, which is what triggers the download denial.

Root Cause: Why Siemens Blocks the Download

Siemens applies two independent gates on restricted files:

1. Export control classification. Some firmware and PLCSIM update packages are flagged under German / EU export-control rules and U.S. EAR. Siemens is required to perform a manual identity check before releasing the file to a registered account.
2. Anti-automation / bot detection. The portal inspects session tokens, browser fingerprints, and request rates. A registered user who suddenly starts requesting restricted blobs, or who triggers heuristics around the download button, can be parked on a manual review queue.

Either gate produces the same visible result: the file is grayed out, an error returns, and a follow-up email is sent. A registered account with a long download history is not immune; the gate is per-request, not per-account.

The Hidden Trigger: PLCSIM V15.1 vs. S7-1200 Firmware 4.3

The reason the PLCSIM V15.1 update is worth pursuing is a hard compatibility boundary in the PLCSIM virtual runtime:

• Stock PLCSIM V15.1 ships an internal image of the S7-1200 firmware envelope. It will accept a TIA Portal project and a real PLCSIM instance up to CPU firmware 4.2.x.
• An S7-1200 CPU running firmware 4.3.x is detected as "unknown CPU type" or "Firmware version not supported" the moment PLCSIM tries to instantiate the slot. The project compiles, the download starts, and the instance aborts.
• The PLCSIM V15.1 update package (document 109764220) refreshes the simulated image to the 4.3 firmware envelope, so a TIA V15.1 project targeting a 4.3 CPU will simulate cleanly.

If your TIA Portal project is built against a 4.3 CPU, you have three options to keep simulating:

1. Install the PLCSIM V15.1 update (the path that is blocked on the portal).
2. Move the project to a newer TIA Portal version whose stock PLCSIM already supports 4.3 (e.g. TIA V16 PLCSIM and higher).
3. Downgrade the S7-1200 firmware to 4.2.x (only if your project code does not use 4.3-only instructions or system blocks).

Solution 1: Submit a Siemens Support Request

This is the documented path and the one that worked in the original case report.

1. Open the Siemens Industry Online Support portal at support.industry.siemens.com and log in with the registered account.
2. Navigate to the document (for example 109764220 - Updates for PLCSIM V15.1).
3. Click "Request download" or the equivalent restricted-download control. A form opens requesting business identity details.
4. Complete the form with the company name, full address, country, intended use, and end-user declaration.
5. Submit. A confirmation email arrives; Siemens performs a manual review (typical turnaround: a few business days, but can be faster for registered accounts).
6. Once approved, the portal releases the file to the account, and a download link is sent by email.

Two practical tips from the field:

• Use the company email domain that matches the registered account. Personal addresses (gmail, outlook) frequently slow down the review.
• Do not start a second parallel Support Request for the same artifact. Siemens cannot cancel an open Support Request, and duplicates will queue against each other.

Solution 2: Use the Totally Integrated Automation UPDATER

Siemens ships a small background service with every TIA Portal installation called the Totally Integrated Automation UPDATER (TIA UPDATER). It is installed under C:\Program Files\Siemens\Automation\TIAPortal\TIA Updater and can scan an installed TIA Portal environment for available hotfixes and PLCSIM updates that are not flagged as restricted.

1. Start TIA Updater from the Windows Start menu (Siemens Automation > TIA Updater).
2. It enumerates installed TIA Portal instances and presents a list of available updates.
3. Select the PLCSIM V15.1 update. The tool either downloads and installs it directly, or it surfaces a link to the Siemens portal for restricted packages.
4. For restricted packages, the updater will route you to the same support page described in Solution 1.

Solution 3: Use the SIMATIC Automation Tool

For S7-1200 firmware blobs (as opposed to the PLCSIM simulator patch), the SIMATIC Automation Tool (SAT) is the supported bulk-update utility and is not subject to the same per-file export gate as the PLCSIM patch.

1. Download the latest SIMATIC Automation Tool from the Siemens support portal (catalog number 6ES7853-2AE00-0AA0 / SAT Tool). No manual approval required for the SAT installer itself.
2. Install SAT on a maintenance laptop with PROFINET or Ethernet access to the S7-1200 subnet.
3. From Tools > Firmware Update, scan the network; SAT identifies each S7-1200 CPU by article number (e.g. 6ES7214-1AG40-0XB0) and current firmware version.
4. Select the target firmware file (downloaded once via the Support Request path or via TIA Updater). SAT flashes the CPU.

SAT is the right tool when a fleet of S7-1200 CPUs needs the same firmware bump and you want to avoid touching each TIA Portal project.

Solution 4: Web Server Firmware Update on the S7-1200

If a Siemens Support Request is in flight and the project is on the bench, you can still update the S7-1200 firmware directly from the CPU's web page, provided the Web Server is enabled in the project.

1. Ensure the S7-1200 project has Web Server = Enable under CPU Properties > Web Server.
2. Build and download the project. Note the IP address of the CPU.
3. Open a browser to http://<cpu-ip>/ and log in with the Web Server user (default: admin with the configured password).
4. Navigate to Module Information > Firmware. The web page lists current firmware and a file-upload control.
5. Upload the firmware blob (file format: .upd) downloaded previously.
6. The CPU restarts into the new firmware. The Web Server preserves its configuration across the restart.

Firmware Update via TIA Portal (Online & Diagnostics)

For a single S7-1200 CPU that is online, TIA Portal V15.1 and later can push a firmware update without leaving the project environment.

1. Connect TIA Portal to the CPU via PROFINET.
2. Open Online & Diagnostics for the CPU device.
3. Select Functions > Firmware Update.
4. Browse to the firmware .upd file. TIA Portal verifies the file matches the article number on the module (e.g. a 6ES7214-1AG40-0XB0 file will not flash a 6ES7214-1BG40-0XB0).
5. Confirm. The CPU restarts. After the restart, TIA Portal shows the new firmware version in the Online & Diagnostics view.

Firmware Update via SIMATIC Memory Card

The offline path is the SIMATIC Memory Card procedure, used when the CPU is not network-accessible.

1. Power off the CPU. Insert the SIMATIC MC (4 MB minimum, 24 MB recommended) into the card slot.
2. On a separate PC, place the firmware .upd on the memory card under the path SIMATIC\S7-1200\FWUPDATE\<artikel_no>\<firmware_file>.upd. On newer CPUs, the directory can be auto-created by TIA Portal when you choose Card Reader/USB > Firmware Update.
3. Insert the card into the powered-off CPU.
4. Power on. The CPU detects FWUPDATE, flashes, and restarts automatically.
5. Remove the memory card; otherwise the CPU will repeat the flash on every power-up.

Compatibility Matrix: TIA Portal vs. S7-1200 Firmware

The matrix above shows why the original report gets stuck: stock PLCSIM V15.1 cannot see a 4.3 CPU, and the hotfix is restricted. If your toolchain is locked to TIA V15.1, the Support Request is the only direct fix.

Verification and Commissioning Checks

After the PLCSIM V15.1 update and the firmware bump, run a fixed sequence of checks before signing off the work order:

1. PLCSIM instance creation. In TIA V15.1, start a new PLCSIM instance. The instance wizard must list 4.3.x as an available CPU firmware.
2. Online & Diagnostics > Module Information. Confirm the S7-1200 reports the new firmware version under the device nameplate.
3. Project download. Re-download the project. TIA Portal should not report "Firmware version not supported."
4. Watch table sanity. Toggle a digital output in a watch table and verify the response, both in PLCSIM and on the real CPU.
5. Web Server access. Open http://<cpu-ip> and confirm the Web Server still answers, since the web-server certificate and user database are preserved across a firmware update on most S7-1200 firmware versions.
6. PROFINET IO check. If the CPU is a PROFINET IO controller, verify that the attached devices (ET 200S, SINAMICS drives) come up green in the topology view.
7. User program retain check. Confirm any RETAIN / persistent DB values are intact after the restart triggered by the firmware flash.

Troubleshooting Matrix

Field-Proven Caveats

• Restricted downloads are per file, not per account. Approval for one PLCSIM hotfix does not auto-approve a different one.
• A Support Request cannot be cancelled once submitted. Plan around a wait of several business days.
• Firmware updates are not undone by a power cycle. To roll back, you must flash an older .upd.
• Do not mix firmware update with project download in the same TIA session without an explicit go-online / go-offline cycle. A race condition on the CPU's online state can cause TIA to display stale firmware information.
• The PLCSIM V15.1 update is a PLCSIM fix only; it does not change anything on the real S7-1200 CPU firmware. The 4.3 firmware on the CPU is a separate file, normally downloadable as a stock item without the export gate.