> 5000VDC Full Isolated Universal USB to CAN Adapter with Industrial-Grade Design --- ## Product Overview The UIC322H is a high-performance USB-to-CAN adapter designed for industrial environments. Based on the Silicon Labs CP2102N USB-to-serial controller, it offers broad operating system compatibility including Windows, Linux (kernel 3.0.0-19 and later), macOS, and Android. The adapter provides **5000 VDC isolation** between the USB and CAN Bus for both power and data, supporting USB virtual COM port baud rates up to 2 Mbps and CAN Bus bit rates up to 1 Mbps. TX and RX lines feature enhanced ESD protection of **±8 kV (contact)** and **±15 kV (air)**, helping protect both the host USB port and connected CAN devices from voltage spikes, static discharge, and transient surges. ::: tip Key Advantages - **5000 VDC full isolation** for both power and signal - **USB powered**, USB 2.0 compliant, full-speed (12 Mbps) - Supports **CAN2.0A** (standard frame) and **CAN2.0B** (extended frame) - Industrial-grade design with rugged cast metal enclosure ::: --- ## Features :::grid{cols=2 style=card} **Isolation & Protection** - 5000 VDC full isolation (power + signal) - ESD protection: ±8 kV (contact), ±15 kV (air) - IEC 61000-4-2 Level 4 compliant **CAN Interface** - CAN2.0A / CAN2.0B support - Bit rates: 50k ~ 1000k bps - ISO 11898 compliant ::: :::grid{cols=2 style=card} **USB Interface** - USB 2.0 full-speed (12 Mbps) - Virtual COM port: 9,600 ~ 2,000,000 bps - Plug & Play, no external power needed **Operating Modes** - Normal Mode - Loopback Mode (internal test) - Listen-Only Mode ::: --- ## Block Diagram  *Figure: UIC322H internal functional architecture — USB to CAN with 5000VDC isolation* --- ## Product Model The UIC322H is a standalone USB-to-CAN adapter. It is part of the UIROBOT protocol converter family. | Model | Interface | CAN Channels | Isolation | ESD Protection | Host Connection | |-------|-----------|-------------|-----------|---------------|-----------------| | **UIC322H** | USB 2.0 (Virtual COM) | 1 x CAN 2.0B | 5000 VDC | ±15 kV (air) | USB Type-A | | UIC321H | RS232 | 1 x CAN 2.0B | 2500 VDC | — | DB9 / Terminal | | UIC324H | RS485 | 1 x CAN 2.0B | 2500 VDC | — | Terminal | --- ## Specifications ### General Information | Parameter | Specification | |-----------|---------------| | Part Number | UIC322H | | Host OS Support | Windows (32/64-bit), Linux (kernel 3.0.0-19+), MacOS 8+, Android | | USB Interface | Type A, Cast Aluminum Alloy, USB1.1/2.0 | | Power | From USB port (no external power required) | ### Isolation & Protection | Parameter | Specification | |-----------|---------------| | USB / CAN Isolation | 5000 VDC | | ESD Protection (TX/RX) | ±8 kV (contact) | | IEC 61000-4-2 (Direct discharge) | 15 kV (Level 4) | | IEC 61000-4-2 (Air discharge) | 15 kV (Level 4) | | MIL-STD-883, Method 3015.7 | 15 kV | ::: warning Important The 5000 VDC isolation protects both the host computer and CAN bus devices from ground loops and voltage transients. Always ensure proper grounding for optimal performance. ::: ### CAN Interface | Parameter | Specification | |-----------|---------------| | Connector | Flip-clip paired connector, 2×2 pin | | Signals | Isolated CANH, CANL, CGND (optional) | | Bit Rates | 50k, 125k, 250k, 500k, 800k, 1000k bps | | Physical Layer | Compliant with ISO 11898 | ### USB Virtual COM Parameters | Parameter | Specification | |-----------|---------------| | Data Bits | 8 (fixed) | | Stop Bits | 1 (fixed) | | Parity | None (fixed) | | Supported Baud Rates | 9,600 / 14,400 / 16,000 / 19,200 / 28,800 / 38,400 / 51,200 / 56,000 / 57,600 / 64,000 / 76,800 / 115,200 / 128,000 / 153,600 / 230,400 / 250,000 / 256,000 / 460,800 / 500,000 / 576,000 / 921,600 / 1,000,000 / 1,200,000 / 1,500,000 / 2,000,000 bps | ### Mechanical & Environmental | Parameter | Specification | |-----------|---------------| | Enclosure | Aluminum | | Cable Length | 1 ft. (30 cm) | | Weight | 50 g | | Operating Temperature | -40°C to +85°C | | Operating Humidity | 5% to 85% RH | | Warranty | 1-year limited warranty | --- ## Wiring  *Figure: UIC322H wiring — White (CANH), Green (CANL), Black (CGND)* ### Wire Color Code | Color | Signal | Description | |-------|--------|-------------| | White | CH | CAN High | | Green | CL | CAN Low | | Black | CGND | CAN Ground | ### Terminal Resistor ::: tip The UIC322H includes a built-in 120Ω terminal resistor that can be enabled via software configuration. For networks with multiple nodes, enable the terminal resistor at both ends of the CAN bus. ::: --- ## Quick Start ### Communication Architecture ```mermaid graph LR A[Host PC] -->|USB| B[UIC322H] B -->|CAN Bus| C[CAN Devices] subgraph "UIC322H Internal" D[CP2102N USB Chip] --> E[UART] E --> F[DSP] F --> G[Digital Isolator] G --> H[CAN Driver] end ``` ### Initialization Steps 1. **Configure Serial Port** - Data bits: 8 - Stop bits: 1 - Parity: None - Select one of the supported baud rates 2. **Initialize UART Baud Rate** ::: warning Critical Step After opening the COM port, send a single byte `0x55` to the UIC322H. This command sets the UART baud rate on the UIC322H side to match the host. ::: 3. **Initialize CAN Controller** - Send a **CAN-CFG Frame** to configure the internal CAN controller - Set CAN bit rate (50k / 125k / 250k / 500k / 800k / 1000k bps) - Set operating mode (Normal / Loopback / Listen Only) 4. **Sending / Receiving CAN Messages** - To transmit: Send a **CAN-TXM Frame** to the UIC322H - To receive: UIC322H sends **CAN-RXM Frame** when CAN message received 5. **Error Handling** - If an error occurs, UIC322H sends an **ERR-MSG Frame** to the host ### Serial Port Debugging Example Below is an example of using a serial port debugging tool to initialize and communicate with the UIC322H:  *Figure: Serial port debug tool — Init UART (0x55), send CAN-CFG/TXM Frame, receive CAN-RXM/ERR-MSG Frame* ### Communication Flow  *Figure: UIC322H communication flow — Host ↔ UIC322H ↔ CAN Bus* ```mermaid sequenceDiagram participant H as Host participant U as UIC322H participant C as CAN Bus H->>U: 0x55 (Init UART) U->>H: ACK H->>U: CAN-CFG Frame U->>H: ACK (if required) loop Data Exchange H->>U: CAN-TXM Frame U->>C: CAN Message C->>U: CAN Message U->>H: CAN-RXM Frame end ``` --- ## UART Protocol ### UART Message Frame Structure All communication uses fixed-length (**18 Bytes**) UART frames: | Byte | 0 | 1 | 2-16 | 17-18 | 19 | |------|---|---|------|-------|----| | Name | AA | CW | Payload | CRC | CC | ::: note Frame Fields - **AA**: Frame header, normally 0xAA (use 0xAD if CRC not required) - **CW**: UART Message Control Word - **Payload**: 15 bytes, content depends on command type - **CRC**: CRC-16/MODBUS (see Appendix 1) - **CC**: Frame ending marker, always 0xCC ::: ::: tip Endianness All multi-byte numeric fields are transmitted in **little-endian** format. - Example: 0x87654321 → send 0x21, 0x43, 0x65, 0x87 ::: ### CAN-CFG Frame (Configuration) The Host must send a CAN-CFG Frame during initialization: | Byte | 0 | 1 | 2 | 3-4 | 5-6 | 7-10 | 11-14 | 15-16 | 17 | |------|---|---|---|-----|-----|------|-------|-------|----| | Name | AA | CW | CFG | 00 | BR0-BR1 | FT0-FT3 | MK0-MK3 | CRC | CC | #### Configuration Fields | Field | Bytes | Description | |-------|-------|-------------| | CW | 1 | 0x01 or 0x81 (require ACK) | | CFG | 1 | EID: 0=Standard ID (11-bit), 1=Extended ID (29-bit) | | BR1:BR0 | 2 | CAN Bit-Rate: 50, 125, 250, 500, 800, 1000 (Kbps) | | FT3:FT0 | 4 | CAN message filter | | MK3:MK0 | 4 | CAN message filter mask | #### Operating Modes | MD1 | MD0 | Mode | Description | |-----|-----|------|-------------| | 0 | 0 | Normal | Standard operation | | 0 | 1 | Loopback | Internal test mode | | 1 | 0 | Listen-Only | Receive without transmitting | | 1 | 1 | Monitor-All | Receive all messages (including errors) | ### CAN-TXM Frame (Transmit) | Byte | 0 | 1 | 2-5 | 6 | 7-14 | 15-16 | 17 | |------|---|---|-----|---|------|-------|----| | Name | AA | CW | ID0-ID3 | DLC | B0-B7 | CRC | CC | | Field | Bytes | Description | |-------|-------|-------------| | CW | 1 | 0x03 or 0x83 (require ACK) | | ID3:ID0 | 4 | CAN ID (32 bits) | | DLC | 1 | Data Length Control Byte | | LEN | - | Number of valid data bytes | | RTR | - | 0=Normal message, 1=Remote Transmission Request | | IDE | - | 0=Standard CAN ID (11-bit), 1=Extended CAN ID (29-bit) | | B0-B7 | 8 | CAN Message Data Bytes | ### CAN-RXM Frame (Receive) | Byte | 0 | 1 | 2-5 | 6 | 7-14 | 15-16 | 17 | |------|---|---|-----|---|------|-------|----| | Name | AA | CW | ID0-ID3 | DLC | B0-B7 | CRC | CC | | Field | Bytes | Description | |-------|-------|-------------| | CW | 1 | 0xD0 | | ID3:ID0 | 4 | CAN ID (32 bits) | | DLC | 1 | Data Length Control Byte | | LEN | - | Number of valid data bytes | | RTR | - | 0=Normal message, 1=Remote Transmission Message | | IDE | - | 0=Standard CAN ID (11-bit), 1=Extended CAN ID (29-bit) | | B0-B7 | 8 | CAN Message Data Bytes | --- ## Error Messages When an error occurs, UIC322H sends error frames to the host: ### Error Codes | Code | Hex | Error Type | Description | |------|-----|------------|-------------| | 0x00 | F0 00 | CAN Not Initialized | CAN-TXM received before CAN-CFG | | 0x01 | F0 01 | Unknown CW | Unrecognized Control Word | | 0x02 | F0 02 | CRC Failure | CRC integrity check failed | | 0x03 | F0 03 | Invalid Bit Rate | Unsupported CAN bit rate | | 0x10 | F1 00 | Frame Too Short | UART frame < 18 bytes | | 0x11 | F1 01 | CAN TX/RX Error | CAN transmit/receive error | ### Error Frame Format ``` AA F0 [Error Code] [Data...] [CRC0] [CRC1] CC ``` ::: danger Important If you receive Error Code 0x00, ensure you have sent the CAN-CFG Frame before attempting to transmit CAN messages. ::: --- ## Get Device Information To retrieve device information such as the serial number: **Request (Host → UIC322H):** ```hex AA 00 00 00 00 00 00 00 00 00 00 00 00 00 00 AB 01 CC ``` or (without CRC): ```hex AD 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 CC ``` **Response (UIC322H → Host):** ```hex AA 00 SN0 SN1 SN2 SN3 00 00 00 00 00 00 00 00 00 CRC0 CRC1 CC ``` Where SN3:SN2:SN1:SN0 is the device serial number (32-bit). ::: tip Example Response: `AA 00 01 02 03 04 00 00 00 00 00 00 00 00 00 1E D6 CC` Serial Number: `0x04030201` (hex) = `006-730-5985` (decimal) ::: --- ## Appendix 1: CRC-16/MODBUS Example Code The following C code shows how to calculate the CRC-16/MODBUS used by the UIC322H UART protocol: ```c // CRC low byte lookup table (256 entries) unsigned char tblCRCLo[256] = { /* ... see datasheet for full table ... */ }; // CRC high byte lookup table (256 entries) unsigned char tblCRCHi[256] = { /* ... see datasheet for full table ... */ }; // Calculate CRC-16/MODBUS // buf: pointer to data starting from CW byte // qty: number of bytes to process (for UIC322H, qty = 14) unsigned short RtuCrc16(unsigned char* buf, unsigned int qty) { unsigned char crcH = 0xFF; unsigned char crcL = 0xFF; int idx = 0; while (qty--) { idx = crcL ^ *buf++; crcL = crcH ^ tblCRCHi[idx]; crcH = tblCRCLo[idx]; } return (crcH << 8) | crcL; } ``` ::: tip Usage Call `RtuCrc16()` with a pointer to the CW byte and length 14 to calculate the CRC for any UART frame. ::: --- ## Safety Precautions ### Electrical Safety | Hazard | Precaution | |--------|------------| | Isolation Voltage | Do not exceed 5000 VDC isolation rating. Ensure proper grounding. | | ESD | Use anti-static precautions when handling. Discharge static before touching connectors. | | Power Supply | The device is USB-powered. Ensure the USB port can supply sufficient current. | ### Operational Safety | Hazard | Precaution | |--------|------------| | Operating Temperature | Use within -40°C to +85°C range. Avoid exposure to extreme temperatures. | | Humidity | Keep within 5% to 85% RH. Do not use in condensing environments. | | Cable Strain | Avoid sharp bends or pulling on the USB cable. Minimum bend radius: 3 cm. | ### CAN Bus Safety | Hazard | Precaution | |--------|------------| | Termination | Enable the built-in 120Ω resistor at both ends of the CAN bus. | | Hot-Plugging | Avoid connecting/disconnecting CAN wires while the system is powered. | | Wiring | Use twisted pair cable for CANH and CANL. Keep CAN bus wiring away from high-voltage lines. | --- ## Downloads - 📖 [UIC322H Datasheet V5.12 (PDF)](https://www.uirobot.com/uploads/files/Manual_UIC322H%20V5.12.pdf) - 📖 [StepEva3 User Manual V4.7 (PDF)](https://www.uirobot.com/uploads/files/Manual_StepEva3%20V4.7.pdf) - 💻 [CP2102N USB Driver](https://www.silabs.com/developers/usb-to-uart-bridge-vcp-drivers) - 💻 [Python CAN Bus Examples](/docs/python-examples) - 💻 [Arduino CAN Bus Examples](/docs/arduino-examples) --- ## Related Documents - [Quick Start Guide](/docs/quick-start) - [CAN Bus Protocol Specification](/docs/can-bus-protocol) - [Python CAN Bus Examples](/docs/python-examples) - [Arduino CAN Bus Examples](/docs/arduino-examples) --- ## Support ::: faq **Q: What operating systems are supported?** A: Windows (32/64-bit), Linux (kernel 3.0.0-19+), MacOS 8+, and Android. **Q: Does it require external power?** A: No, the UIC322H is powered directly from the USB port. **Q: What is the maximum CAN bit rate?** A: The maximum CAN bit rate is 1000 kbps (1 Mbps). **Q: How do I enable the terminal resistor?** A: The terminal resistor can be enabled via CAN-CFG Frame configuration. ::: --- *Last updated: 2026-06-25 | Based on DataSheet V5.12*