Sinamics vs Sinumerik: What's the Difference?

Walk into any Siemens-heavy plant and you will hear both names—Sinamics and Sinumerik—used in the same breath. They sound similar. They often work together. But they are fundamentally different products doing different jobs. Add in competitor families from Rockwell, GE, and FANUC, and the confusion compounds fast. This guide untangles it all.

Sinamics: The Drive Family

Sinamics is a scalable family of drives. The lineup spans from compact single-axis drives used in HVAC and pump applications all the way up to multi-axis servo systems for coordinated motion on production lines. Key sub-families include the G-series (general purpose, scalar or vector control, conveyor/pump/fan duty) and the S-series (servo/vector, closed-loop motion, higher dynamic performance). There are also the GM and GL variants designed for larger power ranges.

The common thread across all Sinamics products: they take an AC or DC power input and deliver precisely controlled power to a motor. Sinamics drives communicate via PROFINET, PROFIBUS, or onboard terminals, and they integrate natively into Siemens TIA Portal and SIMATIC S7 controllers.

Sinumerik: The CNC Platform

Sinumerik is a dedicated CNC system. It interprets part programs (G-code, Siemens-dialect), manages the HMI, handles tool compensation, coordinates multi-axis interpolation, and issues setpoints to the drive layer below it. The operator sees the Sinumerik. The Sinumerik talks to Sinamics drives. The drives spin the motors.

Sinumerik variants cover the range from basic 2-axis turning centers up to 5-axis simultaneous machining systems for aerospace components. The platform includes proprietary safety functions (Safe Torque Off, Safe Speed) that are certified for machine tool applications. It is a specialized product—if you are not building or maintaining a machine tool or grinder, you are likely not dealing with Sinumerik.

How They Work Together

On a CNC machining center, the architecture typically looks like this: Sinumerik CNC at the top, issuing position and velocity setpoints over a high-speed drive bus (Siemens uses a proprietary drive communication interface—refer to your system's documentation for the specific bus standard used on your generation of hardware). Sinamics S-series drives receive those setpoints and close the current and speed loops to the motors. Feedback (encoder signals) travels back up the same path. The machine builder ties it all together; the maintenance tech inherits the result.

Who Are Siemens' Main Competitors?

The industrial automation landscape is crowded. Here is how the major players stack up against Siemens across both drives and CNC:

Rockwell Automation (Allen-Bradley)

Rockwell is Siemens' most direct competitor in North America. Their PowerFlex drive family competes with Sinamics G/S series across most power classes. On the PLC side, ControlLogix and CompactLogix go head-to-head with SIMATIC S7. Rockwell's core focus is PLC and drive integration rather than dedicated machine tool CNC—for CNC-specific machine tool control, they have historically relied on partnerships or motion controller solutions rather than a standalone CNC platform comparable to Sinumerik; confirm the current state of their CNC offerings against your specific application before making assumptions. The question of whether Allen-Bradley is more expensive than Siemens does not have a single answer: it depends on the drive class, the communication options specified, and the distributor. At the list-price level they are broadly comparable for equivalent performance tiers; total cost of ownership swings based on your existing infrastructure and which ecosystem your engineering team already knows. In the surplus market, both brands are widely available and prices are competitive.

FANUC

FANUC is the dominant force in CNC machine tool control globally and competes directly with Sinumerik. On the servo drive and amplifier side, FANUC's servo amplifier families compete with Sinamics S-series in machine tool applications. FANUC also makes standalone servo/spindle drives used outside CNC context. Asking "which is better, FANUC or Siemens?" is genuinely application-dependent. FANUC holds a large share of machine tool OEM design wins, particularly in Asia and in high-volume machining. Sinumerik is stronger in European machine tool builders and in applications requiring tight integration with Siemens PLCs on the same production line. Neither is objectively better—your machine's native control platform is almost always the right choice to stay with unless a full retrofit is planned.

GE / Emerson (formerly GE Automation)

GE's industrial automation business has changed hands over the years—confirm current ownership and branding of the PACSystems line against your specific vintage of hardware, as corporate structures in this space have shifted more than once. GE was historically a legitimate Siemens competitor in PLCs (Series 90, PACSystems) and drives (AF-series). The PACSystems line has continued under successive ownership. GE is not the force in automation it once was, but you will still find GE/Emerson PLCs and drives in legacy installations. In that context, yes—GE was a direct Siemens competitor, particularly in process industries and power generation where GE had strong relationships. For new installations today, the competition is primarily Siemens, Rockwell, Mitsubishi, Omron, and Schneider Electric (EcoStruxure/Modicon).

Other Significant Competitors

• Mitsubishi Electric: Strong in servo drives, CNC (M-series competes with Sinumerik), and PLCs (MELSEC). Dominant in Asia, growing in North America.
• Omron: Drives, PLCs, and motion controllers. Strong in packaging and electronics assembly.
• Danfoss: Drives-focused (VLT and VACON product lines—confirm current sub-brand structure in Danfoss' active catalog). Competes directly with Sinamics G-series in HVAC, pump, and fan applications.
• Schneider Electric: Drives (Altivar), PLCs (Modicon), and HMI. Competes across the full stack.

Common Confusion Points

"My machine has both—which one do I order a spare for?"

Check where the fault appears. A CNC alarm with an axis designation is usually Sinumerik. A drive fault with an F-code on the drive's own display is Sinamics. They carry separate part numbers and are not interchangeable.

"Can I use a Sinamics drive without a Sinumerik?"

Absolutely. Most Sinamics drives are used with standard SIMATIC PLCs (S7-1200, S7-1500, S7-300, S7-400) or even standalone with onboard I/O for simple pump and fan applications. Sinumerik is only required for CNC machine tool control.

"Is Sinamics S120 the same as Sinamics G120?"

No. They are different product families within the Sinamics brand. The G120 is a general-purpose drive; the S120 is a modular servo/vector drive system with a shared DC bus architecture. They have different hardware, different parameter sets, and different application targets. Sub-family designations and variant names (such as G120C, G120X, and S120 Combi) have expanded over time—always verify the exact positioning of the specific variant you are working with against Siemens' current product documentation before ordering a replacement.

"Allen-Bradley vs Siemens: which costs less?"

Both list prices and street prices depend heavily on voltage class, power rating, communications card, and whether you buy new, authorized refurbished, or tested surplus. In the surplus market, well-tested units from either brand can represent significant savings over new. The more useful question is: which platform do your technicians already know? Training and downtime cost more than hardware in most plants.

When Replacement Makes More Sense Than Repair

If a Sinamics drive has a blown power stage or a Sinumerik control unit has a failed display or CPU board, repair costs can approach or exceed the cost of a tested surplus replacement—especially for older variants. Lead times on new Siemens hardware can stretch to weeks or months depending on the module. A tested surplus unit gets you running today.

Disclaimer: This guide is provided for general information only. Procedures vary by model, series, and firmware version. Industrial equipment can cause serious injury, equipment damage, or downtime if serviced incorrectly. Always consult the manufacturer's official documentation and a qualified professional before performing work, and follow your facility's lockout/tagout and safety procedures. PLC Department is an independent surplus supplier and is not affiliated with or endorsed by the manufacturers referenced. Use this information at your own discretion.