AC servo drive
Festo CMMT-AS AC servo drive
Servo drive for EMMT motors and Festo electric axes, from 350 W single-phase to 12 kW three-phase, with EtherCAT, PROFINET, EtherNet/IP and Modbus TCP and STO/SBC up to SIL3 PL e.
Key specifications
| Ingress protection | IP20 |
|---|---|
| Temperature | 0–50 °C |
| Power (max) | 12,000 W |
| Supply | 1-phase 100-230 V AC or 3-phase 200-480 V AC; 24 V DC logic |
| Feedback | EnDat 2.1/2.2, Hiperface, incremental, Sin/Cos, BiSS-C, Nikon-A |
| Fieldbus | EtherCAT, PROFINET RT/IRT, EtherNet/IP, Modbus TCP |
| Continuous current (max) | 25 A |
| Peak current (max) | 75 A |
| Safety | advanced variant adds SS1-r, SS2, SOS, SLS, SMS and PROFIsafe |
| Safe torque off | STO SIL3 / PL e; SBC SIL3 |
Summarised in our own words from Festo SE & Co. KG's published data; series maxima, individual models vary. Last checked 2026-10-30. Source 1
Notes on this data
Currents are per-phase Aeff. Power derates 3%/K above 40 C.
Specify Motion is not affiliated with Festo SE & Co. KG. Festo and CMMT-AS are used only to identify the product. Comparisons use published figures; always confirm against the current datasheet.
Festo CMMT-AS model codes
Published model codes in the CMMT-AS range, with key figures from the manufacturer's data. Search this page for your part number, or send it to us for availability or an equivalent.
| Model code | Nominal current (A) | Nominal power (W) | Supply |
|---|---|---|---|
| CMMT-AS-C2-3A-MP-S1 | 2 | 350 | 230 VAC 1-ph |
| CMMT-AS-C4-3A-MP-S1 | 4 | 700 | 230 VAC 1-ph |
| CMMT-AS-C2-11A-P3-MP-S1 | 1.7 | 800 | 400 VAC 3-ph |
| CMMT-AS-C3-11A-P3-MP-S1 | 2.5 | 1200 | 400 VAC 3-ph |
| CMMT-AS-C5-11A-P3-MP-S1 | 5 | 2500 | 400 VAC 3-ph |
| CMMT-AS-C7-11A-P3-MP-S1 | 7 | 4000 | 400 VAC 3-ph |
| CMMT-AS-C12-11A-P3-MP-S1 | 12 | 6000 | 400 VAC 3-ph |
| CMMT-AS-C18-11A-P3-MP-S1 | 18 | 9000 | 400 VAC 3-ph |
| CMMT-AS-C25-11A-P3-MP-S1 | 25 | 12000 | 400 VAC 3-ph |
Typical applications
Alternatives that meet or exceed these figures
Engineers often come to us with a Festo part number and leave with an alternative that is easier to source, quicker to deliver or a better fit for the machine. These 3 series from our supply network are the closest match on published figures.
Leadshine's EL7 platform spans 220 VAC drives from 400 W to 2 kW, 400 VAC drives to 7.5 kW and an 11-22 kW high-power range, all with STO and EtherCAT, Modbus/pulse or PROFINET variants.
| Published maximum | CMMT-AS | EL7S / EL7 Series AC Servo Drives |
|---|---|---|
| Continuous current | 25 A | 44 A meets or exceeds |
| Peak current | 75 A | 88 A meets or exceeds |
| Power | 12,000 W | 22,000 W meets or exceeds |
| Axes | — | 1 |
Network-capable AMC digital drives spanning 10-747 VDC and 120-480 VAC, up to 150 A continuous and 250 A peak (27.4 kW peak power), in PCB, panel, machine and vehicle formats. They support almost any motor type and feedback, plus CANopen, EtherCAT, POWERLINK and Modbus.
| Published maximum | CMMT-AS | DigiFlex Performance Servo Drives (DP,… |
|---|---|---|
| Continuous current | 25 A | 150 A meets or exceeds |
| Peak current | 75 A | 250 A meets or exceeds |
| Power | 12,000 W | 27,400 W meets or exceeds |
The second-generation Kinco JD drive, paired with SMK motors from 50 W to 7.5 kW. It accepts a very wide range of encoder protocols plus a second encoder, runs CANopen or EtherCAT, and has STO SIL3 / PL e on every model.
| Published maximum | CMMT-AS | JD2 Series AC Servo Drives |
|---|---|---|
| Continuous current | 25 A | 26 A meets or exceeds |
| Peak current | 75 A | 65 A |
| Power | 12,000 W | 7,500 W |
| Axes | — | 1 |
Figures are the highest published for each series and are not always measured the same way. A higher figure is not automatically a better choice: mounting, duty cycle, feedback, connectors and approvals matter too. An engineer will check the fit against your application before recommending anything.
What an AC servo drive is
An AC servo drive, or servo amplifier, powers and controls a servo motor from mains supply. It rectifies the AC input to a DC bus, then uses an inverter of power transistors switched by PWM to produce controlled three-phase current in the motor. Nested current, velocity and position loops use encoder feedback to follow commands from pulse and direction, analogue or industrial Ethernet. Modern drives add auto-tuning, vibration suppression and safety functions such as safe torque off.
When engineers choose an AC servo drive
Choose an AC servo drive for mains-powered machines with servo axes from tens of watts to many kilowatts, such as packaging, machine tools and robotics. It gives precise, dynamic control with standard industrial interfaces. The trade-offs are cabinet space, wiring, EMC measures and the need to match motor and feedback. For low-voltage or mobile machines, a DC drive is more suitable; for many axes in one cabinet, a multi-axis drive may save space.
How to specify the Festo CMMT-AS
Send these with your enquiry and an engineer can confirm the right CMMT-AS variant or an equivalent:
- Supply voltage and phases (V AC)
- Continuous and peak output current (A rms)
- Motor and feedback compatibility
- Command interface: pulse, analogue, EtherCAT, PROFINET and so on
- Safety functions, such as STO, and their rating (SIL, PL)
- Braking resistor and regenerative energy (W, J)
- Ambient temperature, mounting and cooling
Common mistakes to avoid
- Sizing on motor rated current without the drive's peak duration
- Ignoring regenerative energy on fast decelerations or vertical axes
- Leaving out EMC filtering and screened motor cables
- Mixing motor and encoder types the drive does not support
Festo CMMT-AS: frequently asked questions
What is the Festo CMMT-AS?
Servo drive for EMMT motors and Festo electric axes, from 350 W single-phase to 12 kW three-phase, with EtherCAT, PROFINET, EtherNet/IP and Modbus TCP and STO/SBC up to SIL3 PL e. Published series figures include temperature 0 °C, temperature 50 °C, power 12,000 W, continuous current 25 A. It is made by Festo SE & Co. KG; Specify Motion can help source it or propose an equivalent.
Who makes the Festo CMMT-AS?
The Festo CMMT-AS is made by Festo (Festo SE & Co. KG) and is listed here for engineers comparing options. Specify Motion is not affiliated with Festo SE & Co. KG; brand names are used only to identify the product.
What model codes are in the Festo CMMT-AS range?
The CMMT-AS range includes CMMT-AS-C2-3A-MP-S1, CMMT-AS-C4-3A-MP-S1, CMMT-AS-C2-11A-P3-MP-S1, CMMT-AS-C3-11A-P3-MP-S1, CMMT-AS-C5-11A-P3-MP-S1, CMMT-AS-C7-11A-P3-MP-S1, CMMT-AS-C12-11A-P3-MP-S1, CMMT-AS-C18-11A-P3-MP-S1 and 1 more. The table on this page lists each published model code with its key figures. Send us the code you use, or the one you need to replace, and our engineers will confirm availability, lead time or the closest equivalent.
What is the temperature of the Festo CMMT-AS?
The published series minimum temperature is 0 °C. Individual models and sizes in the CMMT-AS range vary, so check the exact variant against your duty cycle, mounting and environment, or ask our engineers to confirm the right size for you.
Is there an alternative to the Festo CMMT-AS?
Yes. On published figures, Leadshine EL7S / EL7 Series AC Servo Drives and ADVANCED Motion Controls DigiFlex Performance Servo Drives (DP, DZ, DV) are the closest match from our supply network. An engineer confirms the fit against your application before recommending anything.
Does a servo drive need a braking resistor?
When a servo motor decelerates, it acts as a generator and returns energy to the drive's DC bus. If the bus capacitors cannot absorb it, the voltage rises and the drive trips. A braking resistor dissipates the energy as heat. Fast decelerations, high inertia and vertical axes usually need one.
What is safe torque off on a servo drive?
Safe torque off, or STO, is a safety function that removes power that could produce torque at the motor, without disconnecting the drive supply. It is defined in IEC 61800-5-2 and used as part of a machine's safety system. Check the safety level achieved and wiring requirements.
Further reading: How to select a servo drive · How to select a servo motor · Servo drives
Other ac servo drive series
Spec builder
Specify what you need instead of CMMT-AS
Select every part you need, answer the questions an applications engineer would ask, and see your summary before we ask for any details.
- 1Products
- 2Performance
- 3Environment
- 4Volumes
- 5Your spec
Engineer support
Let our experienced engineers do the hard work for you
Tell us how you use the Festo CMMT-AS: the load, speed, duty and environment. Our engineers will confirm whether it is still the right part, find it for you, or propose an alternative that fits better.
- Reviewed by an engineer, not an autoresponder
- Like-for-like and better-fit alternatives
- Standard, modified and custom options
Prefer to configure it? Use the spec builder.