CPU 1510SP F-1 PN Hardware Overview and SIL 2 Context
The Siemens CPU 1510SP F-1 PN is the fail-safe variant of the ET 200SP distributed controller. The F-CPU integrates a second processor core that executes the safety program in parallel with the standard program, providing redundant safety computation on a single piece of hardware. The module is certified for safety functions up to SIL 2 (Safety Integrity Level 2) per IEC 61508, SIL 2 CL 2 per IEC 62061, and PL d / Category 3 per ISO 13849-1. Communication with fail-safe I/O is handled via PROFIsafe over PROFINET, encapsulated in standard PROFINET frames; the F-bit travels inside the PROFINET payload and is decoded by the F-I/O modules.
For any SIL 2 application, you must program the F-CPU with the F-programming tools supplied with STEP 7 Safety Advanced. The standard STEP 7 Professional package alone cannot create or compile the F-blocks, the F-runtime group, or the PROFIsafe parameters required for a safety program. The standard 1510SP-1 PN (no "F") cannot execute a safety program at all and must never be used in a safety function. The CPU 1510SP F-1 PN is identified in the TIA Portal hardware catalog and on the module label as "CPU 1510SP F-1 PN".
Required Software Stack for SIL 2 Programming
Programming the CPU 1510SP F-1 PN requires a complete, version-aligned TIA Portal software stack. Mixing major versions between the TIA Portal, STEP 7 Professional, and STEP 7 Safety Advanced packages will block compilation of the F-program with a clear version-mismatch error.
| Component | Version | Function |
|---|---|---|
| TIA Portal | V16 (or matched) | Engineering framework, project tree, device catalog |
| STEP 7 Professional | V16 | Standard PLC programming, hardware configuration |
| STEP 7 Safety Advanced | V16 | F-CPU programming, F-block types, F-runtime group, PROFIsafe configuration |
| SIMATIC Automation Tool | ≥ V3.0 SP3 | Optional: license transfer, firmware update, mass commissioning |
STEP 7 Safety Advanced is a separately licensed option package installed on top of TIA Portal. Once installed, it activates:
- The F-CPU device family in the hardware catalog under SIMATIC CPU > ET 200SP CPU > CPU 1510SP F-1 PN
- F-block types (F-FB, F-FC, F-DB, F-I/O DB) in the Libraries pane
- The F-runtime group editor and the safety administration editor
- PROFIsafe slot configuration for ET 200SP F-modules
- Collective signature and safety log generation
License Architecture: STEP 7 Safety Advanced
Three license tiers are relevant for any engineer commissioning the CPU 1510SP F-1 PN:
| License | Type | Required for |
|---|---|---|
| STEP 7 Professional V16 | Floating or single license | Engineering the standard program and hardware configuration |
| STEP 7 Safety Advanced V16 | Floating or single license | Engineering, compiling, and downloading the F-program |
| CPU Runtime License | "Small" minimum (per manual) | Runtime execution of OPC UA client/server and other premium runtime features |
The CPU Runtime License is documented in the device manual as required for OPC UA client mode and other premium runtime features. The "Small" license is the minimum tier; "Medium" and "Large" unlock additional runtime capabilities. The runtime license lives on the SD card of the F-CPU and is recognized at startup; a missing runtime license does not block safety operation, only the premium runtime features.
Trial Version Behavior and Download Capability
Siemens sells a 21-day trial of STEP 7 Safety Advanced. The trial install is functionally complete; it exposes the F-CPU family, the F-block library, the F-runtime group editor, and the PROFIsafe configuration. The trial license is delivered through the ALM and is recognized as valid for the trial period. During the trial:
- F-blocks compile without restriction
- The compiled F-program is signed with a valid collective signature
- Download to the F-CPU is permitted
- The F-CPU runs the program in safety mode exactly as it would with a purchased license
After the trial expires, the engineering environment continues to open, but:
- F-blocks cannot be recompiled; the compiler returns a license error
- The F-runtime group editor is grayed out
- Any change to the F-program requires a valid license to recompile and re-download
A trial-built F-program that is already loaded into the CPU continues to execute indefinitely; trial expiry does not stop the running safety program. To modify the program, install the purchased Safety Advanced license on the same ALM, re-open the project, recompile, and re-download.
Answer: Can a Trial-Version Program Be Downloaded to a Fail-Safe CPU?
Yes. The TIA Portal trial license is a valid Siemens license during the 21-day trial window. You can download a compiled F-program to the CPU 1510SP F-1 PN from a trial installation, and the F-CPU will execute the program in safety mode as it would any licensed project. The trial license does not embed any runtime restriction on the target CPU.
Two preconditions must be met:
- The trial license must still be valid (not expired) at the moment of download.
- The F-program must compile without errors. The Safety Advanced compiler is fully active in the trial.
After expiry, the project file remains editable in read-only mode for F-blocks. To restore full engineering, install the purchased Safety Advanced license and re-open the project on the same engineering PC.
Required Safety Libraries for SIL 2 Programming
STEP 7 Safety Advanced installs two sets of safety-related elements that you must use to build a SIL 2 program.
1. F-Block Library (Global Library)
After installation, the library is registered in the TIA Portal Libraries pane under Global libraries > Safety_Advanced > F-Blocks. The library contains certified F-block types for typical safety functions:
| F-Block Family | Function | Typical SIL / PL |
|---|---|---|
| F-Estop / F-FB-Estop | Emergency-stop evaluation with discrepancy monitoring, cross-fault detection | SIL 2 / PL d |
| F-SDoor / F-Lock | Safety door monitoring with optional lock feedback | SIL 2 / PL d |
| F-SFCO / F-SFCT | Safety feedback circuit monitoring (output readback) | SIL 2 / PL d |
| F-Muting | Muting function for light curtains in material-flow applications | SIL 2 / PL d |
| F-Count / F-Limit | SIL-rated counters, limit value comparison, overspeed detection | SIL 2 |
| F-TIM | SIL-rated timer with discrepancy monitoring | SIL 2 |
2. F-I/O Blocks (Device-Specific)
For each ET 200SP F-module (F-DI 4/8, F-DO 4, F-PM-E, F-Relay) the Safety Advanced installation drops a matching F-I/O block in the hardware catalog. These blocks are pre-certified for PROFIsafe V2.4 / V2.6.1 and expose typed tag interfaces for the F-program, including:
- Input value (BOOL / INT / REAL per channel)
- Quality bits (valid, passivated, discrepancy, ground fault, short circuit)
- ACK tag (acknowledgement of re-integration after passivation)
- Passivation tag (manual channel passivation for test)
F-Block Programming Rules
Safety blocks are restricted in the language constructs they may contain. The Safety Advanced compiler enforces these rules; violation is reported as a compile error in the F-block:
| Allowed in F-blocks | Forbidden in F-blocks |
|---|---|
| Bit logic (AND, OR, XOR, contact, coil) | Indirect addressing (PEEK, POKE, ANY, pointer, VARIANT) |
| Standard timers / counters (in F-CPU specific types) | Standard DB write from outside the F-runtime group |
| F-I/O direct tag access | Direct I/O access (I, Q, PIW, PQW) on standard I/O |
| F-DB read/write from inside the F-runtime group | Calls to non-certified FC/FB (SCL, STL legacy code) |
| Comparison, math on F-tag data types | Communication SFBs (PUT, GET, BSEND) inside F-blocks |
Step-by-Step: Commissioning a SIL 2 Project on CPU 1510SP F-1 PN
- Install the software stack. Install TIA Portal V16 first, then STEP 7 Professional V16, then STEP 7 Safety Advanced V16. Restart the ALM service to register the new options.
- Transfer licenses. Use the Automation License Manager to move the Safety Advanced license to your local PC or license server. Confirm the license appears as "STEP 7 Safety Advanced V16" with a green status.
- Create a new project. In TIA Portal, choose Create new project > Add new device > SIMATIC CPU > ET 200SP CPU > CPU 1510SP F-1 PN. If the F-CPU family is missing from the catalog, the Safety Advanced installation is not detected; repair the installation via the Windows Apps & Features menu.
- Configure PROFIsafe addresses. In the device view, open the F-CPU properties > F-parameter. Set the F-destination address (range 1..65534, default 1) and the F-monitoring time (typical 100..500 ms, default 100 ms). The monitoring time must exceed three times the worst-case PROFINET update time.
- Add the F-runtime group. In the program blocks tree, right-click Program blocks > Add new F-runtime group. The group is called cyclically between OB1 and the F-CPU's safety cycle.
- Insert F-blocks. Drag F-FB types from the Safety_Advanced global library into the F-runtime group. Compile the F-program. The compiler generates a collective F-signature stored in the F-CPU's safety administration.
- Assign F-I/O. From the hardware catalog, drag ET 200SP F-DI/F-DO modules into the slots. Set each module's F-source address (the F-CPU IP-derived) and F-destination address; TIA Portal auto-generates the typed I/O DB.
- Configure safety passwords. In the F-CPU properties > Protection > Safety Administration, set the F-passwords for read and write access. The read password allows online diagnostics; the write password is required for any change to the F-program.
- Compile and download. Right-click the F-CPU > Compile > Download to device. Enter the safety write password. The F-CPU performs a safety check; on success, it transitions to RUN with safety mode active and the SAFETY LED turns solid green.
- Perform acceptance test. Use the safety administration editor to print the F-signature and the F-program structure. Document each safety function (E-stop, door, guard) in the acceptance report per IEC 62061 / ISO 13849-1. The acceptance report is a regulatory document; archive it for the lifetime of the machine.
PROFIsafe Parameter Reference
| Parameter | Typical Value | Notes |
|---|---|---|
| F-destination address | 1..65534 (default 1) | Must match the F-module DIP switch or HW config |
| F-source address | CPU IP-derived (auto) | Set automatically by TIA Portal from CPU IP |
| F-monitoring time | 100..500 ms (min 100 ms) | ≥ 3 × worst-case PROFINET update time |
| F-CRC version | V2.6.1 (default) | Must match the F-module firmware |
| Passivation behavior | Channel-level (default) | Configurable per channel in HW config |
| Discrepancy time | 50..3000 ms | Per F-input; depends on sensor type |
Verification: Confirming the F-Program Runs Correctly
After download, perform the following checks in order:
- Online diagnostics. In the TIA Portal, go Online > Online & diagnostics > Safety Administration. The collective F-signature must match the value from the last successful compile; a mismatch indicates a corrupted download.
- Safety mode LED. The CPU 1510SP F-1 PN front panel shows a dedicated SAFETY LED. Solid green = safety mode active, flashing = test stop / passivation, off = safety not licensed or not configured.
- PROFIsafe status. Open Online > Online & diagnostics > PROFIsafe for each F-module. Status word bit 0 = valid, bit 1 = passivated, bit 6 = CRC error, bit 7 = timeout.
- Discrepancy test. Force each F-input channel to its safe state (open E-stop, open door) and verify the F-output de-energizes within the configured F-monitoring time.
- Signature log. Print the safety log from Online > Safety log. The log must be archived as part of the acceptance test record.
Troubleshooting Matrix
| Symptom | Probable Cause | Resolution |
|---|---|---|
| F-CPU missing from hardware catalog | STEP 7 Safety Advanced not installed, or wrong version (V17 on a V16 portal) | Reinstall Safety Advanced matching TIA Portal V16 |
| "F-block not compiled" error | License expired or TIA version mismatch | Check ALM, re-compile with valid license |
| Download blocked at safety check | Wrong safety write password | Reset password via Safety Administration using the master password |
| SAFETY LED off | Safety program not loaded, signature mismatch, or wrong F-CPU | Re-download, verify collective signature, confirm F-variant on label |
| PROFIsafe CRC error on a channel | Wrong F-destination address or duplicate address in network | Verify each F-module's F-address matches the HW config |
| F-input permanently passivated | Discrepancy time too short, sensor fault, wiring break | Increase discrepancy time, check sensor wiring with a meter |
| Trial expired mid-project | License timed out | Install purchased license, re-open project on the same PC |
| "F-Runtime Group not generated" | Compiler error inside an F-block (indirect addressing, pointer, ANY) | Open F-block offline, replace restricted constructs with F-typed operations |
| CPU in STOP after download | Missing or corrupted F-I/O DB | Recompile, check the I/O DB against the hardware configuration |
| OPC UA client fails to start | No CPU Runtime License ("Small") on the SD card | Transfer "Small" license to the SD card via SIMATIC Automation Tool or TIA Portal |
Cross-Platform Notes: F-CPU Family Comparison
The programming workflow for the CPU 1510SP F-1 PN is identical to the larger S7-1500 F-CPUs (CPU 1515F-2 PN, CPU 1516F-3 PN/DP, CPU 1517F-3 PN/DP, CPU 1518F-4 PN/DP MFP). All F-CPUs use the same STEP 7 Safety Advanced option package and the same F-block library. Differences across the family are limited to:
- Bit memory, work memory, and load memory size
- Number of PROFINET / PROFIBus interfaces
- Motion / technology object count
- OPC UA server capabilities (tied to the CPU Runtime License tier)
The ET 200SP F-CPU shares the same PROFIsafe V2.6.1 stack as the S7-1500 F-CPUs, so F-modules certified for one platform are usable on the other. The CPU 1510SP F-1 PN is positioned for distributed installations with a smaller standard program footprint, while the S7-1500 F-CPUs are rack-mounted and typically handle larger standard plus safety programs.
Field Commissioning Checklist
- Confirm the F-CPU article number ends in the "F" variant on the module label.
- Verify the TIA Portal, STEP 7 Professional, and Safety Advanced versions match exactly (V16 / V16 / V16).
- Confirm the Safety Advanced license is green in the ALM of the engineering PC that performs the download.
- Set the F-destination address on every F-module (DIP switch or HW config) to a unique value within 1..65534.
- Configure F-monitoring time ≥ 3 × worst-case PROFINET update time, with 100 ms minimum.
- Document the F-passwords in a sealed envelope per your site security policy.
- Print and archive the safety log and the collective F-signature after each download.
- Perform the acceptance test with a witness from the safety authority or your quality department.
Do I need a separate license to program the CPU 1510SP F-1 PN for SIL 2?
Yes. Beyond STEP 7 Professional V16, you must install STEP 7 Safety Advanced V16 and transfer a valid Safety Advanced license (Floating or Single) to the Automation License Manager. The trial version of Safety Advanced is valid for 21 days and can compile and download a working F-program during the trial window.
Where are the safety libraries for SIL 2 located in TIA Portal?
After installing STEP 7 Safety Advanced V16, the F-block library is registered under Libraries > Global libraries > Safety_Advanced > F-Blocks. The library includes F-Estop, F-SDoor, F-SFCO, F-Muting, and other certified F-block types for typical SIL 2 functions.
Can a program built with the Safety Advanced trial version be downloaded to a fail-safe CPU?
Yes. The trial license is a valid Siemens license during the 21-day trial. You can compile and download the F-program to the CPU 1510SP F-1 PN. After trial expiry, recompilation is blocked until a purchased license is installed on the same ALM; the running safety program on the CPU continues to execute.
What is the difference between CPU 1510SP-1 PN and CPU 1510SP F-1 PN?
The F-variant adds a second processor core for parallel safety execution, PROFIsafe protocol support, and certification for SIL 2 (IEC 61508) and PL d / Category 3 (ISO 13849-1). The standard variant cannot execute a safety program and must not be used in safety functions.
What PROFIsafe monitoring time should I use for a typical ET 200SP F-network?
For most ET 200SP F-CPU applications, a PROFIsafe F-monitoring time of 100..500 ms is appropriate. Set the value to at least 3× the worst-case PROFINET update time, with a 100 ms minimum. Insufficient monitoring time causes sporadic passivation of F-I/O.