CM Series - Smart Motors with Incremental Encoder
UIROBOT CM Series — CAN bus smart servo stepper motors with integrated incremental encoder, driver, and motion controller. Available in NEMA 8 to NEMA 34.
The CM Series from UIROBOT is a range of CAN bus smart servo stepper motors that integrate an incremental encoder, driver, and motion controller into a single compact unit. Built on the trusted UIM342 platform, these motors deliver closed-loop positioning, high-speed operation up to 4500 RPM, and daisy-chain connectivity over a simple two-wire CAN bus.
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## Key Features
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**Integrated Design**
Motor, incremental encoder, driver, and motion controller combined in one unit — no external controller required.
**CAN 2.0B Communication**
Two-wire CAN bus (CANH / CANL) with up to 1 Mbps data rate. Complies with ISO-11898. Supports daisy-chain topology for multi-axis systems.
**Closed-Loop Control**
Real-time position feedback with backlash compensation and stall detection. Eliminates lost steps common in open-loop stepper systems.
**Microstepping Resolution**
Full step to 1/128 microstep, configurable via software. Ensures smooth, vibration-free motion at low speeds.
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**Wide Supply Voltage**
16–24 VDC for NEMA 8 and NEMA 11 models; 24–48 VDC for NEMA 17 and larger. Flexible integration into various power architectures.
**Integrated I/O**
3 digital inputs (with continuous, low-pass filtered, and single-trigger modes) and 1 digital output (5 V). Inputs support change-of-state notification.
**Brake Options**
Select models available with embedded electromagnetic brake for vertical axis and hold-to-stop applications.
**Protection Built-In**
Overcurrent, overvoltage, and overtemperature protection standard across all models.
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## Product Lineup
The CM Series covers five motor frame sizes from NEMA 8 to NEMA 34, with optional brake variants for NEMA 17 and above.
### Motor Specifications
| Model | Frame Size | Holding Torque | Rotor Inertia | Rated Current | Supply Voltage | Brake | Encoder | Weight |
|-------|-----------|---------------|--------------|--------------|---------------|-------|---------|--------|
| UIM2040CM | NEMA 8 (20 mm) | 0.038 N·m | 2.9 g/cm² | 0.6 A | 16–24 VDC | — | Incremental | 83 g |
| UIM2852CM | NEMA 11 (28 mm) | 0.16 N·m | 18 g/cm² | 0.8 A | 16–24 VDC | — | Incremental | 218 g |
| UIM4247CM | NEMA 17 (42 mm) | 0.43 N·m | 75 g/cm² | 1.68 A | 24–48 VDC | — | Incremental | 418 g |
| UIM4247CMB | NEMA 17 (42 mm) | 0.43 N·m | 75 g/cm² | 1.68 A | 24–48 VDC | Embedded | Incremental | 510 g |
| UIM5756CM | NEMA 23 (57 mm) | 1.26 N·m | 300 g/cm² | 2.8 A | 24–48 VDC | — | Incremental | 810 g |
| UIM5756CMB | NEMA 23 (57 mm) | 1.26 N·m | 300 g/cm² | 2.8 A | 24–48 VDC | Embedded | Incremental | 990 g |
| UIM8696CM | NEMA 34 (86 mm) | 6.5 N·m | 1900 g/cm² | 6 A | 24–48 VDC | — | Incremental | 3200 g |
| UIM8696CMB | NEMA 34 (86 mm) | 6.5 N·m | 1900 g/cm² | 6 A | 24–48 VDC | Embedded | Incremental | 3800 g |
### Step Angle
| Parameter | Value |
|-----------|-------|
| Intrinsic step angle | 1.8° |
| After microstepping (1/128) | 0.0140625° |
### Order Code Structure
```
UIM [Motor Frame] [Motor Length] C M B [User Code]
Motor Frame:
20 = NEMA 8 28 = NEMA 11 42 = NEMA 17
57 = NEMA 23 86 = NEMA 34
C = CAN bus
M = Incremental Encoder
B = Embedded Brake □ = No Brake
```
**Example**: UIM5756CMB = NEMA 23 frame, 56mm length, CAN bus, incremental encoder, with brake
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## Evaluation Kits
Ready-to-use kits for prototyping and system evaluation. Each kit includes a controller board, power supply, USB cable, and software.
| Kit | Motor Size | Includes |
|-----|-----------|----------|
| UIMEVA 342SKIT | NEMA 8 / NEMA 11 | UIM342S controller, cables, software |
| UIMEVA 342LKIT | NEMA 17 / NEMA 23 | UIM342L controller, cables, software |
| UIMEVA 342KIT | NEMA 23 / NEMA 34 | UIM342 controller, cables, software |
---
## Applications
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**Medical Devices**
Pipetting systems, centrifuges, imaging stages. Quiet, precise motion for lab environments.
**Scientific Instruments**
Spectrometers, microscopes, optical tables. Sub-degree accuracy with encoder feedback.
**Industrial Automation**
Pick-and-place, conveyor indexing, packaging. Reliable multi-axis coordination over CAN bus.
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## Safety Precautions
### Electrical Safety
| Hazard | Precaution |
|--------|------------|
| High Voltage | Disconnect power before wiring. Use within specified voltage range only. |
| Short Circuit | Ensure proper wire gauge and insulation. Install a fuse on the power input line. |
| Grounding | Properly ground all devices to a common ground. Strictly prohibit hot-plugging while power is on. |
### Operational Safety
| Hazard | Precaution |
|--------|------------|
| Overheating | Ensure adequate ventilation. Operating temperature: -20°C to +70°C. |
| ESD | Use anti-static precautions when handling. Discharge static before touching terminals. |
| Mounting | Secure the device firmly. Do not operate with loose mounting. |
### Mechanical Safety
| Hazard | Precaution |
|--------|------------|
| Moving Parts | Keep clear of rotating shafts during operation. Wait for motor to stop before handling. |
| Load Limits | Do not exceed rated torque and speed limits to prevent mechanical damage. |
| Coupling | Ensure proper alignment between motor shaft and load to avoid vibration and wear. |
---
## Related Products
| Product | Description |
|---------|-------------|
| [UIM342](/docs/uim342) | Detailed technical reference, wiring, and configuration |
| CA Series | CAN bus smart motors with absolute encoder |
| UIC320A | USB to CAN 2.0B adapter (isolated) |
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## Resources
:::tip
For complete technical specifications, wiring diagrams, CAN network configuration, motion control modes, and instruction set reference, see the **[UIM342 CAN Bus Smart Servo Stepper Motor Controller](/docs/uim342)** page.
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Download the full product manual, 2D/3D CAD drawings, and example code from the [UIROBOT Download Center](https://www.uirobot.com/serve/list-437.html).
- **User Manual** — UIM342 V6.05
- **2D / 3D Drawings** — STEP and DXF formats
- **Example Code** — C#, Python, MATLAB
- **Debugging Software** — UIMotionSuite
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*Last Updated: 2026-06-25 | Based on UIM342 User Manual V6.05*
> 💡 This page is a product family overview. For detailed technical specifications, wiring diagrams, CAN network configuration, motion control modes, and instruction set reference, refer to the **[UIM342 technical document](/docs/uim342)**.
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## Video Tutorial
:::video[Multiple Sets of UIM342 CAN BUS Smart Motor Controllers](https://www.youtube.com/watch?v=47IxpesNrGc)
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:::video[How to Control UlM342 CANBUS Servo Stepper Smart Motors Using Arduino+ Ul-MCP2515](https://www.youtube.com/watch?v=GLb7F3KFpPc)
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:::video[How to use USB-CAN analyzer to control UIM342 series smart motor?](https://www.youtube.com/watch?v=OaR_IqltHxY)
:::
> 📺 [More Video](https://www.youtube.com/@UIROBOT-ZJ)
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*Last updated: 2026-07-01*