The **PSI-REP-DNET-CAN** is an industrial-grade repeater manufactured by Phoenix Contact. It is specifically designed for **DeviceNet** and **CANopen** systems to provide signal conditioning, electrical isolation, and bus segmentation. ### 1. Key Technical Specifications The device acts as an interface between two segments of a CAN-based network. | Feature | Specification | | :--- | :--- | | **Input Voltage** | 18 V DC ... 30 V DC | | **Current Consumption** | Approx. 45 mA | | **Transmission Speed** | 10 kbps to 1 Mbps (Auto-detection) | | **Isolation** | 3-way isolation (VCC // CAN A // CAN B) | | **Connection Method** | COMBICON plug-in screw terminals | | **Mounting** | DIN rail NS 35 | --- ### 2. Electronic Architecture & Components The internal electronics are designed to solve common physical layer issues in industrial communication: #### A. Signal Regeneration (Retiming) The repeater does not simply amplify noise; it receives the bitstream, digitizes it, and re-transmits it with "fresh" edge transitions. This allows you to extend the total length of the network beyond the standard limits of a single segment. #### B. 3-Way Galvanic Isolation This is a critical electronic safety feature. The internal circuitry isolates: 1. **Port A (Input)** 2. **Port B (Output)** 3. **Power Supply** This prevents ground loops and protects sensitive PLC hardware from high-voltage surges occurring on the fieldbus cable. #### C. Integrated Termination The device features integrated termination resistors. These can be activated via DIP switches located on the front of the housing. This eliminates the need for external 120-ohm resistors at the end of the segments. #### D. Error Detection and Filtering The electronics include logic to detect "babbling idiots" (nodes that jam the bus) or short circuits. If a fault is detected on one segment, the repeater can isolate that branch to prevent the entire network from crashing. --- ### 3. Connection Interface The unit uses standardized terminal blocks for easy wiring. | Terminal | Description | | :--- | :--- | | **V+ / V-** | 24V DC Power Input | | **CAN_H** | High signal line | | **CAN_L** | Low signal line | | **GND** | Reference ground for CAN | | **Shield** | Connection for cable shielding / PE | --- ### 4. LEDs and Diagnostics The faceplate contains several LEDs that indicate the electronic status: * **VCC:** Green (Power supply is OK). * **CAN A:** Yellow (Data traffic on Port A). * **CAN B:** Yellow (Data traffic on Port B). * **ERR:** Red (Bus error or collision detected).