Siemens Industry Online Support
Siemens AG
Entry type: FAQ Entry ID: 89257657, Entry date: 12/01/2021

Which firmware and SIMATIC Memory Card do you need for the S7-1500 CPU and which remedy is possible if the CPU is no longer accessible after the update?

  • Entry
  • Associated product(s)
The following provides information about the firmware update, a table with the recommended SIMATIC Memory Cards and the remedies if the S7-1500 CPU does not switch to RUN anymore.

1. Firmware updates for the S7-1500 CPUs

You can update the operating system of your S7-1500 controller using a SIMATIC Memory Card, via the TIA Portal or via the integrated web server. The firmware updates available for all the S7-1500 controllers are at this link: Firmware updates for the SIMATIC S7-1500 

Find the operating system update using the article number of your S7-1500 CPU and then follow the instructions to update the firmware of your controller and benefit from the firmware improvements.

2. SIMATIC Memory Card (SMC) for the firmware update

The following table shows you which SIMATIC Memory Card (SMC) you need to do an offline firmware update for an S7-1500 CPU.  

S7-1500 CPU Article no. of the SIMATIC Memory Card 
CPU 15116ES7954-8LL03-0AA0 (256MB)
6ES7954-8LP03-0AA0 (2GB)
6ES7954-8LT03-0AA0 (32GB)
CPU 15126ES7954-8LL03-0AA0 (256MB)
6ES7954-8LP03-0AA0 (2GB)
6ES7954-8LT03-0AA0 (32GB)
CPU 15136ES7954-8LL03-0AA0 (256MB)
6ES7954-8LP03-0AA0 (2GB)
6ES7954-8LT03-0AA0 (32GB)
CPU 15156ES7954-8LL03-0AA0 (256MB)
6ES7954-8LP03-0AA0 (2GB)
6ES7954-8LT03-0AA0 (32GB)
CPU 15166ES7954-8LL03-0AA0 (256MB
)6ES7954-8LP03-0AA0 (2GB)
6ES7954-8LT03-0AA0 (32GB)
CPU 15176ES7954-8LL03-0AA0 (256MB
)6ES7954-8LP03-0AA0 (2GB)
6ES7954-8LT03-0AA0 (32GB)
CPU 1518
6ES7954-8LL03-0AA0 (256MB)
6ES7954-8LP03-0AA0 (2GB)
6ES7954-8LT03-0AA0 (32GB)

With the SIMATIC Memory Cards 6ES7954-8LL03-0AA0 (256MB), 6ES7954-8LP03-0AA0 (2GB) and 6ES7954-8LT03-0AA0 (32GB) you can save multiple updates for the different modules so that you can upgrade your modules one after the other.

3. Remedy for faulty firmware update

In some cases it can happen that after a firmware update of the S7-1500 CPU from a firmware version V2.5.x or lower to a firmware version V2.6.1 or higher the CPU is no longer accessible. The CPU remains in STOP mode and all the LEDs flash at a frequency of approx. 2Hz.

Normally the CPU shows this behavior if the SMC is defective or not accepted. In this case, however, the SMC very probably contains trace files or measurements.

There are remedies for this:

  • Remedy 1
  1. Downgrade the CPU firmware back to V2.5 or lower.
  2. With STEP 7 (TIA Portal) establish an online connection to the CPU. Optionally you can save existing traces / measurements online or delete them. 
  3. Update the CPU again to firmware V2.6.1 or higher.
  • Remedy 2
  1. Download the project data (FW V2.5) offline in the PG to the SMC.
  2. Slot the SMC into the CPU that you updated previously with the firmware V2.6 or higher.
  • Remedy 3
  1. Slot an empty SMC in the CPU V2.6 that you updated previously with the firmware V2.6 or higher.
  2. Set the CPU mode selector to STOP.
  3. Download the available STEP 7 (TIA Portal) project to the CPU.
  1. Set the CPU mode selector to STOP.
  2. Using the menu command “File operations > Delete data logs" in the SIMATIC Automation Tool you delete the data log data on the SMC.
  3. Update the CPU again to firmware V2.6.1 or higher.

For individual programmable logic controllers it is also possible to simply delete the contents of the memory card before upgrading the firmware.

This system behavior will be cleared in firmware versions >V2.8.x.

4. Further Information

  • Description of Firmware Update for S7-1500 CPU and Displays
    Entry ID 77492231
  • How do you detect an inconsistently or incorrectly formatted SIMATIC Memory Card (SMC) and how do you repair it?
    Entry ID 69063974
  • SIMATIC S7-1500 Automation System
    Entry ID 59191792 

A list of the current operating systems of the S7-1200 CPUs is available in Entry ID 77430184.  

Security information
In order to protect technical infrastructures, systems, machines and networks against cyber threats, it is necessary to implement – and continuously maintain – a holistic, state-of-the-art IT security concept. Siemens’ products and solutions constitute one element of such a concept. For more information about cyber security, please visit
Rate entry
no rating
Requests and feedback
What do you want to do?
Note: The feedback always relates to the current entry / product. Your message will be forwarded to our technical editors working in the Online Support. In a few days, you will receive a response if your feedback requires one. If we have no further questions, you will not hear from us.