# RS485 to Ethernet Module Installation Guide ## Overview This guide provides step-by-step instructions for installing a 2-Channel RS485 to Ethernet adapter module to connect Modbus devices (thermostats) to a network. ## Hardware Requirements - 2-CH RS485 to Ethernet adapter module - Existing 24V DC transformer - RS485/Modbus devices (e.g., thermostats) - Appropriate wiring (shielded twisted pair recommended for RS485) ## Module Specifications - **Power Input**: 6-36V DC (24V DC typical) - **RS485 Channels**: 2 independent channels - **Ethernet Ports**: 2 ports (either can be used for network, other for cascading) ## Connection Diagram ### Power Connections ``` 24V DC Transformer RS485 Module ┌─────────────┐ ┌──────────────────┐ │ │ │ │ │ + 24V ───┼────────────┼──→ 6-36V Input │ │ │ │ │ │ - GND ───┼────────────┼──→ Ground │ │ │ │ │ └─────────────┘ └──────────────────┘ ``` ### RS485 Data Connections ``` Electrical Panel RS485 Module XCOM Terminal Group ┌──────────────────────┐ ┌─────────────────────┐ │ │ │ │ │ Device 1 (String 1) │ │ RS485 Channel 1 │ │ ├─ T+ (Data+) ──────┼───────────┼──→ A │ │ ├─ T- (Data-) ──────┼───────────┼──→ B │ │ └─ GND ─────────────┼───────────┼──→ Signal Ground │ │ │ │ │ │ Device 2 (String 2) │ │ RS485 Channel 2 │ │ ├─ T+ (Data+) ──────┼───────────┼──→ A │ │ ├─ T- (Data-) ──────┼───────────┼──→ B │ │ └─ GND ─────────────┼───────────┼──→ Signal Ground │ │ │ │ │ └──────────────────────┘ └─────────────────────┘ ``` ### Complete System Overview ``` ┌─────────────────┐ │ 24V DC Power │ │ Transformer │ └────────┬────────┘ │ ┌────────▼──────────────────────────┐ │ RS485 to Ethernet Module │ │ │ │ Power: 6-36V Input, Ground │ │ │ │ RS485-1: A, B, GND │ │ RS485-2: A, B, GND │ │ │ │ Ethernet: ETH1 or ETH2 ────────► To Network │ │ └──────┬─────────────┬──────────────┘ │ │ ┌─────────▼─────┐ ┌───▼────────────┐ │ Thermostat │ │ Thermostat │ │ String 1 │ │ String 2 │ │ (via Modbus) │ │ (via Modbus) │ └───────────────┘ └────────────────┘ ``` ## Installation Steps ### 1. Safety First ⚠️ **IMPORTANT**: Disconnect all power before beginning installation. ### 2. Power Connection 1. Locate the existing 24V DC transformer 2. Connect the module's **6-36V Input** terminal to the transformer's **+ (positive)** output 3. Connect the module's **Ground** terminal to the transformer's **- (negative)** output **Wire colors (typical)**: - Red: +24V DC - Black: Ground/Common ### 3. RS485 Data Connections #### Understanding the XCOM Terminal Group In your electrical panel's XCOM group, you'll find: - First set of wires: RDZ HMI connections - Following pairs: Two RS485 pairs for two strings of thermostats #### Connection Notes - **T+** on devices connects to **A** on the module - **T-** on devices connects to **B** on the module - **PE/GND** connects to **Signal Ground** on the module - Some wires may be unmarked - verify with continuity testing #### Wiring Each Channel Connect each RS485 device string to one of the two module channels: **For String 1** (any channel - e.g., RS485-1): ``` Device T+ ──→ RS485-1 A Device T- ──→ RS485-1 B Device GND ─→ RS485-1 Signal Ground ``` **For String 2** (remaining channel - e.g., RS485-2): ``` Device T+ ──→ RS485-2 A Device T- ──→ RS485-2 B Device GND ─→ RS485-2 Signal Ground ``` > **Note**: The assignment of devices to Channel 1 or Channel 2 is flexible. Choose either channel for each device string - the specific mapping doesn't matter as thermostat identification is done after discovery through the network. ### 4. Verify Connections **Before applying power**: 1. ✅ Check continuity between Wi-SA connectors and module terminals 2. ✅ Verify correct polarity on power connections 3. ✅ Ensure RS485 wires are properly paired (A-to-A, B-to-B) 4. ✅ Confirm all ground connections are secure ### 5. Ethernet Connection 1. Connect an Ethernet cable from either **ETH1** or **ETH2** to your network switch/router 2. The second Ethernet port can be used for router cascading if needed ### 6. Power On and Test 1. Restore power to the 24V DC transformer 2. Check the module's LED indicators: | LED | Description | |-----|-------------| | **PWR** | Power indicator - should be solid | | **NET** | Network indicator - blinks when connected to Ethernet | | **LINK1** | Lights up when establishing RS485 Channel 1 connection | | **ACT1** | Lights up when Channel 1 is transmitting data | | **LINK2** | Lights up when establishing RS485 Channel 2 connection | | **ACT2** | Lights up when Channel 2 is transmitting data | ## Important Notes - ⚠️ Use **shielded twisted pair cable** for all RS485 connections to minimize interference - ⚠️ Maintain proper polarity: A↔A (T+), B↔B (T-), GND↔GND - ⚠️ Power input must be within **6-36V DC** range (24V DC is typical) - ⚠️ Either Ethernet port functions identically - choose whichever is more convenient - ℹ️ Channel assignment is flexible - devices can be connected to either RS485-1 or RS485-2 - ℹ️ Device discovery and mapping is performed after installation via network configuration ## Troubleshooting | Issue | Possible Solution | |-------|------------------| | PWR LED not lit | Check 24V DC power connections and voltage | | NET LED not blinking | Verify Ethernet cable and network connection | | LINK LED not lit | Check RS485 wiring polarity (A, B, GND) | | No device communication | Verify continuity of RS485 cables; check for proper termination | ## Post-Installation After successful installation: 1. Access the module's web interface via its IP address 2. Configure network settings if necessary 3. Perform device discovery to identify all connected Modbus devices 4. Map thermostats/devices to their physical locations 5. Test communication with each device ## Safety and Compliance - Installation should be performed by a **qualified electrician** - Follow all local electrical codes and regulations - Ensure proper grounding of all equipment - Use appropriate wire gauges for the application ## Additional Resources - Consult the module's technical documentation for advanced configuration - Refer to device-specific manuals for RS485 settings (baud rate, parity, etc.) --- **Revision**: 1.0 **Last Updated**: January 2026