# CA Series - Smart Motors with Multi-Turn Absolute Encoder The CA Series from UIROBOT is a range of CAN bus smart servo stepper motors that integrate a multi-turn absolute encoder, driver, and motion controller into a single compact unit. Unlike incremental encoder models, the CA Series retains position information across power cycles — eliminating the need for homing sequences. Built on the trusted UIM342A 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. --- ## Key Features :::grid{cols=2 style=card} **Absolute Multi-Turn Encoder** Remembers exact position across power cycles. No homing required — saves startup time and eliminates reference-point errors in mission-critical applications. **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. ::: :::grid{cols=2 style=card} **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. ::: --- ## Product Lineup The CA 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 | |-------|-----------|---------------|--------------|--------------|---------------|-------|---------|--------| | UIM2040CA | NEMA 8 (20 mm) | 0.038 N·m | 2.9 g/cm² | 0.6 A | 16–24 VDC | — | Absolute | 95 g | | UIM2852CA | NEMA 11 (28 mm) | 0.16 N·m | 18 g/cm² | 0.8 A | 16–24 VDC | — | Absolute | 232 g | | UIM4247CA | NEMA 17 (42 mm) | 0.43 N·m | 75 g/cm² | 1.68 A | 24–48 VDC | — | Absolute | 441 g | | UIM4247CAB | NEMA 17 (42 mm) | 0.43 N·m | 75 g/cm² | 1.68 A | 24–48 VDC | Embedded | Absolute | 533 g | | UIM5756CA | NEMA 23 (57 mm) | 1.26 N·m | 300 g/cm² | 2.8 A | 24–48 VDC | — | Absolute | 830 g | | UIM5756CAB | NEMA 23 (57 mm) | 1.26 N·m | 300 g/cm² | 2.8 A | 24–48 VDC | Embedded | Absolute | 1010 g | | UIM8696CA | NEMA 34 (86 mm) | 6.5 N·m | 1900 g/cm² | 6 A | 24–48 VDC | — | Absolute | 3200 g | | UIM8696CAB | NEMA 34 (86 mm) | 6.5 N·m | 1900 g/cm² | 6 A | 24–48 VDC | Embedded | Absolute | 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 A B [User Code] Motor Frame: 20 = NEMA 8 28 = NEMA 11 42 = NEMA 17 57 = NEMA 23 86 = NEMA 34 C = CAN bus A = Absolute Multi-Turn Encoder B = Embedded Brake □ = No Brake ``` **Example**: UIM5756CAB = NEMA 23 frame, 56mm length, CAN bus, absolute multi-turn encoder, with brake --- ## Absolute vs Incremental Encoder | Feature | CA (Absolute) | CM (Incremental) | |---------|--------------|-----------------| | Position after power loss | Retained | Lost — requires homing | | Homing sequence | Not required | Required at startup | | Multi-turn tracking | Yes (up to 65536 turns) | No | | Best for | Vertical axes, safety-critical | General-purpose, cost-sensitive | :::tip Choose the CA Series when your application requires reliable position retention across power cycles — especially for vertical axes, medical devices, and safety-critical systems. ::: --- ## 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 342ASKIT | NEMA 8 / NEMA 11 | UIM342A-S controller, cables, software | | UIMEVA 342ALKIT | NEMA 17 / NEMA 23 | UIM342A-L controller, cables, software | | UIMEVA 342AKIT | NEMA 23 / NEMA 34 | UIM342A controller, cables, software | --- ## Applications :::grid{cols=3 style=card} **Medical Devices** Pipetting systems, centrifuges, imaging stages. Absolute position retention ensures consistent startup without recalibration. **Scientific Instruments** Spectrometers, microscopes, optical tables. Multi-turn tracking enables long-travel precise positioning. **Industrial Automation** Pick-and-place, conveyor indexing, packaging. No homing reduces downtime and improves throughput. ::: --- ## 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. | --- ## Video Tutorial ▶️ Watch on YouTube: [PVT Motion Test with UIROBOT Absolute Encoder Smart Motor](https://www.youtube.com/watch?v=RNANLvPnk3E) --- ## Related Products | Product | Description | |---------|-------------| | [UIM342A](/docs/uim342a) | Detailed technical reference, wiring, and configuration | | CM Series | CAN bus smart motors with incremental encoder | | CM Series | CAN bus smart motors with incremental encoder | | UIC320A | USB to CAN 2.0B adapter (isolated) | --- ## Resources :::tip For complete technical specifications, wiring diagrams, CAN network configuration, motion control modes, and instruction set reference, see the **[UIM342A CAN Bus Smart Servo Stepper Motor Controller](/docs/uim342a)** page. ::: 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** — UIM342A V6.05 - **2D / 3D Drawings** — STEP and DXF formats - **Example Code** — C#, Python, MATLAB - **Debugging Software** — UIMotionSuite --- *Last Updated: 2026-06-25 | Based on UIM342A 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 **[UIM342A technical document](/docs/uim342a)**. --- *Last updated: 2026-07-08*