Problem Details
A newly commissioned machining center running a SINUMERIK 840D sl control offers no program simulation. The softkey for simulation is missing, greyed out, or the control refuses to run the program in test mode. Programs are generated offline in CAM and transferred to the machine, so the shop only wants simulation as a last-line sanity check before cutting air — but the function simply is not there.
This is almost never a fault. On SINUMERIK solution line controls, graphical simulation is a licensed software option, not a base function of the operating software. If the option was not ordered with the machine, or was ordered but never activated in the license set of the delivered CF card, the function stays locked.
Root Cause: Option Not Licensed
The relevant catalog item for milling simulation is:
| Field | Value |
|---|---|
| Order number (MLFB) |
6FC5800-0AP21-0YB0 (flat form 6FC58000AP210YB0) |
| Description | SINUMERIK 840Di sl / 840D sl Simulation Milling (2D dynamic, 3D static) |
| Type | Software option — delivery of a license |
| Scope | 2D dynamic simulation and 3D static simulation for milling |
Two practical consequences of the option scope:
- 2D dynamic means the tool path is drawn as the block-by-block interpretation runs. Useful for checking travel envelope, contour shape and gross programming errors.
- 3D static means a solid-style result view, not a continuously animated 3D machine model. Do not expect full machine-kinematic collision detection from this option; that is a different functional class and must be confirmed separately for your machine.
- The order number is the milling variant. Turning simulation is a separate item — do not assume one license covers both technologies.
Because the license is delivered as a paper/electronic license tied to the hardware serial number of the CompactFlash card in the NCU, ordering the option and physically having it enabled on the machine are two separate events. A machine can leave the builder with the option purchased but the license key not yet regenerated, particularly if the CF card or NCU was swapped during commissioning.
Step 1: Confirm What Was Actually Ordered
- Pull the order confirmation / sales contract for the machine and search for
6FC5800-0AP21-0YB0or the wording "Simulation Milling". Options are itemized separately from the base control package. - If the machine builder supplied a documentation set, check the machine option list and the delivered license certificate (Certificate of License, CoL). The CoL carries the license number needed for activation.
- If the option is not on the order, it was not bought. It can be purchased afterwards through the machine builder or Siemens sales; retrofitting a license does not require hardware changes, only a new license key for the existing CF card serial number.
Step 2: Read the Option and License State on the Control
Work on the control HMI. Exact softkey wording depends on whether the machine runs HMI Advanced or SINUMERIK Operate and on the software version, so navigate by function rather than by literal label:
- Switch to the commissioning/setup area of the HMI and open the licensing dialog (typically Setup → Licenses, or Startup → Licenses).
- Note the hardware serial number of the CF card shown in that dialog. Every license key is bound to this number. Record it exactly, including leading characters.
- Open the list of all options. Each entry shows the option, whether it is set (activated in the machine data) and whether it is licensed.
- Locate the simulation milling entry and classify the state using the table below.
| Option set | Licensed | Interpretation | Action |
|---|---|---|---|
| No | No | Option never purchased or never enabled | Verify order; purchase license if absent, then activate |
| Yes | No | Option bit set without a valid license — control will report a licensing alarm | Generate/enter the correct license key for this CF serial number |
| No | Yes | License present, option bit not enabled | Set the option in the option machine data and power cycle |
| Yes | Yes | Fully enabled; symptom lies elsewhere | Check operating mode, access level, and HMI configuration |
Step 3: Activate the License
- Collect data: CF card hardware serial number, the license number(s) from the Certificate of License, and the control's product/type designation.
- Assign the license to the hardware serial number using the Siemens web-based license management service. This produces a license key string that encodes all licensed options for that CF card.
- Enter the license key in the licensing dialog on the control. Entering a new key replaces the previous one, so the key must cover every option already licensed on that card — not just simulation. Record the old key before overwriting it.
- Set the option bit if the license dialog does not do it implicitly. Option machine data are in the protected commissioning area and require the corresponding access level (manufacturer or service password).
- Perform an NCK reset / control power cycle. Option machine data are effective at power-on ("po" activation class). Without the restart, the option stays inactive even though it reads as set.
Step 4: Verification
- Reopen the license/options list and confirm the simulation entry shows both set and licensed with no pending licensing alarm.
- Confirm no licensing-related alarm remains in the alarm list after the power cycle. A "license missing" style alarm typically self-clears once the correct key is present and the control restarts.
- Load a short, known-good CAM-posted program from the part program directory and start simulation. The 2D dynamic view must trace the tool path as the program is interpreted.
- Verify the 3D static view renders the finished stock representation. If blank, check that a blank/stock definition is present or configured for the simulation, since simulation with no defined blank has nothing to remove material from.
- Run a program that deliberately exceeds a software limit switch and confirm the simulation flags it. This proves the simulation is actually interpreting against machine data, not just drawing geometry.
If Simulation Is Licensed but Still Fails
| Symptom | Probable cause | Check |
|---|---|---|
| Softkey visible, nothing happens | HMI in the wrong operating area or program not selected | Select the program in the program manager first, then start simulation |
| Simulation aborts at a specific block | Cycle, transformation or high-speed-setting call the simulation cannot interpret without its own option | Identify the block; check whether the referenced function (e.g. a transformation or compressor function) is itself an unlicensed option |
| Empty 3D view | No blank defined | Define a blank in the program header or workpiece setup |
| Tool path drawn but wrong dimensions | Tool data or zero offsets differ from the CAM assumption | Compare active tool offsets and work offset (G54 series) with the CAM setup sheet |
| Softkey missing entirely after licensing | Required HMI software component not installed on the CF card | Compare installed HMI software version/scope with the version that contains the simulation package for your control |
Note the workflow implication for a CAM-driven shop: machine-side simulation on the 840D sl verifies the posted NC code against the control's own interpretation, including active tool offsets, work offsets and software limits. That is a different and complementary check to CAM-side verification, which validates against the CAM model and post assumptions. Where budget only allows one, the machine-side check catches post-processor and offset errors that CAM verification structurally cannot see.
Practical Notes for Machine Acceptance
- Add "all ordered software options set and licensed, verified on the license page" to the acceptance checklist. Photograph or export the option list at handover.
- Archive the license key string and the CF card hardware serial number with the machine documentation. If the CF card fails, the replacement card has a new serial number and needs a re-assigned key; without the license numbers this becomes a slow commercial process.
- Keep a full commissioning archive (NC and PLC) offline. Option changes are a common trigger for needing a restore.
- When comparing quotes between machine builders, check option lists line by line. Base control price differences frequently reflect which software options are bundled.
FAQ
What is the order number for SINUMERIK 840D sl milling simulation?
The software option is 6FC5800-0AP21-0YB0 (flat form 6FC58000AP210YB0), described as SINUMERIK 840Di sl / 840D sl Simulation Milling with 2D dynamic and 3D static simulation, supplied as a license delivery.
Why is the simulation softkey missing on my new 840D sl machine?
Simulation is a licensed option, not a base function. If the option was not ordered, or was ordered but the license key was never assigned to the CF card serial number, the function stays locked. Check the license/options page on the HMI to see whether the option is set and licensed.
Can I add the simulation option after the machine is delivered?
Yes. It is a license-only option requiring no hardware change. Purchase the license through the machine builder or Siemens sales, assign it to the CF card hardware serial number to generate a new license key, enter the key, set the option, and power cycle the control.
Does entering a new license key erase my other options?
The license key encodes all licensed options for that CF card, so the newly generated key must include every option already licensed. Record the existing key before overwriting it and confirm the full option list after activation.
Does the milling simulation option also cover turning?
No. The order number identifies the milling variant. Turning simulation is a separate option and must be ordered and licensed independently.