Offline Loading Siemens SIMATIC SD Cards for S7-1200/S7-1500

Overview

Writing a TIA Portal project directly to a Siemens SIMATIC Memory Card (SMC) from a PC, without an online connection to the PLC, is a supported commissioning workflow for the S7-1200 and S7-1500 families. The card is prepared at the engineering workstation using a standard USB SD card reader, transported to the site, and inserted into the CPU. On the next power-up, the CPU detects the load job on the card, copies the project into internal load memory, and starts with that configuration.

Two procedural paths exist in TIA Portal:

1. Online card programming through the PLC's PG/PC interface (the traditional path requiring a TCP, PROFIBUS, or PROFINET connection to the CPU).
2. Offline card programming by writing the transfer file (SIMATIC.S7S / S7_JOB.S7S) to a removable SD reader mounted as a Windows drive letter.

Path 2 is the focus of this document. It removes the dependency on a live PLC connection, which is the standard approach for machine builders who pre-configure spare cards at the office and ship them to remote sites, and for commissioning engineers working in environments where the CPU is installed but not yet networked to engineering.

Card Format and the SIMATIC File System

The SMC is not a generic SD card. Siemens pre-formats the card with a proprietary file system on top of FAT/FAT32. The card contains:

• A hidden Siemens boot sector that the CPU firmware recognizes on power-up.
• A SIMATIC.S7S container with the user program, hardware configuration, and connection data.
• An optional S7_JOB.S7S text file that defines a one-shot operating action (for example, transfer program to internal flash, copy RAM to ROM, or delete card content).
• Optional SIMATIC.HMI / LOG / recipe folders used as a portable file system by the user program at runtime.

SMC Article Numbers and Capacity Selection

S7-1200 and S7-1500 use the same physical card form factor (SDHC) but different firmware partitions. A card written for an S7-1200 cannot boot an S7-1500 and vice versa. Always order the variant specified for the target CPU family.

Card Reader Hardware Requirements

Any USB-attached SD/SDHC reader that presents the card as a removable drive in Windows is sufficient. There is no vendor lock-in.

• Built-in notebook SD slot (Realtek, Genesys Logic, JMicron controllers) — supported.
• External USB 2.0 / USB 3.0 SD reader (Anker, Ugreen, Transcend, Integral, SanDisk ImageMate) — supported.
• USB 3.0 hub between reader and PC — supported but avoid high-bandwidth hubs if you see intermittent read errors on 32 GB cards.

For reliable operation with 32 GB SDHC cards, prefer USB 3.0 readers that support UHS-I or higher. Older USB 2.0 readers occasionally corrupt writes when the card controller negotiates a bus speed the reader cannot sustain.

Prerequisites

• TIA Portal V13 SP1 or later installed on the engineering PC. Procedure is identical in V15.1, V16, V17, V18, V19. Slight menu wording differences may apply between major versions.
• Siemens SIMATIC Memory Card matched to the target CPU family.
• USB SD card reader (or built-in SD slot).
• A built TIA Portal project that has completed consistency check (Project > Compile > Software (rebuild all blocks)) with no errors.
• PC user account with write access to the card reader drive letter.

Step-by-Step Procedure

1. Insert the SMC into the USB card reader on the engineering PC. Wait for Windows to mount the volume. The card appears as a drive with label "SIMATIC MC" (S7-1200) or "SIMATIC S7" (S7-1500) depending on family.
2. Open the TIA Portal project for the target machine.
3. Select the target CPU station in the Project Tree.
4. Trigger the offline transfer using one of two equivalent methods:
   • Menu path: Project > Card Reader/USB Memory > Write to memory card > select the reader drive > confirm.
   • Drag-and-drop: Drag the CPU station icon from the Project Tree onto the card reader drive in the project tree's "Card Reader/USB Memory" node. This is documented in Siemens Support entry 48711409.
5. Choose the load action in the dialog:
   Transfer (user program + hardware config) — standard offline load.
   Copy RAM to ROM — if the card contains a backed-up image and you want to refresh internal flash.
   Delete user program — factory reset via card.
6. Confirm the write. TIA Portal reports progress; a 24 MB card typically completes in 5–15 seconds over USB 3.0, a 32 GB card with a large project may take 30–90 seconds.
7. Verify the card by opening the drive in Windows Explorer. Confirm:
   • SIMATIC.S7S file exists with non-zero size matching the project.
   • Free space on card has decreased proportionally.
   • No S7_JOB.S7S remains (TIA Portal removes the job file after writing).
8. Eject the card safely through the Windows task tray "Safely Remove Hardware" icon. Skipping this step is the single most common cause of corruption on 32 GB SDHC cards.
9. Transport and install the card in the target CPU's card slot at the site.

Card Insertion and PLC Boot Behavior

The CPU evaluates the card on every restart. Behavior depends on whether the card contains a valid program, a job file, or both.

Differences Between S7-1200 and S7-1500 Cards

Inserting an S7-1500 card into an S7-1200 (or vice versa) results in a CPU diagnostic buffer entry "Card type not compatible" with STOP. The CPU is not damaged, but the card is not consumed.

Firmware Update from Card (S7-1500)

An S7-1500 SMC can also carry a firmware update. To use this offline path:

1. Download the correct firmware upgrade package for the target CPU article number from Siemens Support (entry ID depends on CPU, e.g., 6ES7516-3AN02-0AB0 V2.9.x).
2. In TIA Portal, Online > Accessible devices > [CPU] > Online & Diagnostics > Functions > Firmware update.
3. Select the card reader as the source. TIA Portal writes the FWUPDATE.S7S folder.
4. Insert the card into the target CPU. On power-up, the CPU upgrades firmware, restarts, and runs in STOP with the new firmware version.

Know-How Protection and Card Binding

For S7-1500, blocks can be bound to the SMC serial number through TIA Portal's block properties > Protection > Know-how protection > Bind to serial number of the SIMATIC Memory Card. This prevents the block from executing on a CPU that does not see the bound card on startup. This is a separate mechanism from the offline transfer workflow and is typically used by OEMs delivering machine code that must run only on a specific installed card.

Troubleshooting Matrix

Verification Procedure at the Site

1. Insert the SMC into the CPU with the PLC powered off.
2. Power on the CPU.
3. Observe the MAINT LED flashing during transfer (typical 5–60 seconds depending on project size).
4. Confirm the CPU enters RUN. The RUN LED should be solid green; STOP LED off; MAINT off.
5. Open TIA Portal online, connect to the CPU, and verify: Online & Diagnostics > Diagnostic buffer shows "Transfer of project from card successful" with timestamp matching the power-up.
6. Compare the online hardware configuration to the offline project: Online > Compare offline/online. No differences should appear for the CPU and attached I/O.

Best Practices and Field-Proven Caveats

• Always perform the consistency check (Project > Compile > Software) before writing the card. A project with unresolved references transfers, but the CPU will refuse to start and logs an "Inconsistency detected" entry.
• Label each SMC with the project name, target CPU article number, and write date. Cards from multiple projects are visually identical.
• Store SMCs in anti-static cases. The cards are not ruggedized for industrial shop-floor handling.
• Never write a card while another TIA Portal instance has an online connection to the same CPU. The simultaneous write can desynchronize the CPU's view of the transfer job.
• For S7-1500 firmware updates, use a dedicated 32 GB card (e.g., 6ES7954-8LF03-0AA0). Smaller cards will reject the firmware package.
• When shipping cards to remote sites, include the project checksum file (print from TIA Portal > Project > Properties > Info) so the receiving engineer can validate the project integrity.
• If the receiving site has older TIA Portal versions, set the project "TIA Portal version" target before writing the card. Otherwise the CPU may reject the project with "Version too new".

Related Siemens Support References

The following official documentation applies to the workflows described above:

• Support entry 48711409 — Download project data into the S7-1200/S7-1500 CPU without TIA Portal
• SIMATIC S7-1200 Programmable Controller System Manual
• SIMATIC S7-1500 Automation System System Manual
• TIA Portal Information System — keyword "Card Reader/USB Memory" under project tree context help.

FAQ