Connecting an encoder described as EnDat 2.2 through an SMC40 requires two separate checks: identify the SINUMERIK family and installed firmware, then determine whether the SMC40 will participate in safety functions. “NCU 720.2” identifies hardware; it is not the firmware version needed for the compatibility decision.
Separate NCU Hardware from Firmware
Do not use NCU 720.2 as the software compatibility value. Retrieve the exact SINUMERIK firmware version from the control and record the complete version, service pack, and hotfix level. The available evidence does not identify the installed firmware, so it cannot establish whether the existing cabinet is compatible or which component must be upgraded.
Apply the SMC40 Firmware Thresholds
| SINUMERIK platform | Application category | Minimum stated version |
|---|---|---|
| SINUMERIK 840D sl | Without safety | V4.5 SP2 HF4 |
| SINUMERIK 828D | Without safety | V4.5 SP2 HF1 |
| SINUMERIK 840D sl | With safety | V4.7 SP1 |
| SINUMERIK 828D | With safety | V4.7 HF2 |
Compare the complete installed firmware string with the applicable row. “Or higher” applies within the stated platform and application category; it does not establish compatibility between different SINUMERIK families or prove that the encoder itself is supported.
Interpret “With Safety” Correctly
The distinction concerns whether the SMC40 is used in an application involving safety functions. Meeting only the without-safety threshold does not establish SMC40 support for safety use. The evidence does not identify the machine’s safety configuration, encoder model, or installed firmware, so do not infer safety compatibility from the NCU hardware designation or the reported EnDat 2.2 interface.
Determine the Required Upgrade
- Read the exact SINUMERIK firmware version, including its service pack and hotfix level.
- Identify whether the control is SINUMERIK 840D sl or SINUMERIK 828D and whether the SMC40 must support safety functions.
- Compare those findings with the corresponding minimum version in the table.
- If the firmware is below the applicable threshold, evaluate a firmware upgrade. If it meets the threshold, continue with encoder-specific compatibility checks rather than assuming that hardware replacement is required.
- Before changing hardware or firmware, submit the machine configuration to Siemens through an official Support Request. Siemens documentation referenced by the evidence is available at https://support.industry.siemens.com/cs/ww/en/view/66000716.
Include the SINUMERIK family, NCU 720.2 hardware designation, complete firmware string, SMC40 identification, encoder model and interface, and intended safety use in the request. These inputs are necessary to decide whether the firmware, SMC40, encoder interface, or another cabinet component requires a change.
FAQ
Is NCU 720.2 a SINUMERIK firmware version?
No. NCU 720.2 is a hardware designation. Retrieve the complete firmware version, service pack, and hotfix level before evaluating SMC40 compatibility.
What firmware supports SMC40 on SINUMERIK 840D sl?
The stated minimum is V4.5 SP2 HF4 without safety and V4.7 SP1 with safety. Select the threshold that matches the machine’s actual safety use.
What firmware supports SMC40 on SINUMERIK 828D?
The stated minimum is V4.5 SP2 HF1 without safety and V4.7 HF2 with safety. Confirm the complete installed version and encoder-specific compatibility with Siemens before upgrading.