8.5 KiB
8.5 KiB
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
- Locate the existing 24V DC transformer
- Connect the module's 6-36V Input terminal to the transformer's + (positive) output
- 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:
- ✅ Check continuity between Wi-SA connectors and module terminals
- ✅ Verify correct polarity on power connections
- ✅ Ensure RS485 wires are properly paired (A-to-A, B-to-B)
- ✅ Confirm all ground connections are secure
5. Ethernet Connection
- Connect an Ethernet cable from either ETH1 or ETH2 to your network switch/router
- The second Ethernet port can be used for router cascading if needed
6. Power On and Test
- Restore power to the 24V DC transformer
- 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:
- Access the module's web interface via its IP address
- Configure network settings if necessary
- Perform device discovery to identify all connected Modbus devices
- Map thermostats/devices to their physical locations
- 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