1. Introduction
The ComWinTop CWT-BSR series Modbus IO modules are versatile data acquisition and control units designed for industrial automation. These modules feature various input/output ports, including Digital Input (DI), Digital Output (DO), Analog Input (AI), and Analog Output (AO), making them suitable for a wide range of applications in buildings, HVAC systems, fire safety, water management, petrochemical industries, environmental protection, and more.
Each module is equipped with RS232 and RS485 communication ports, supporting the MODBUS RTU protocol for seamless integration with PLCs, DCS systems, HMIs, and SCADA systems. Robust interference protection ensures data accuracy and reliability in demanding industrial environments.
Figure 1: CWT-BSR-DI40B Module Front View
Video 1: CWT-BSR Series Product Overview
2. Setup and Installation
2.1 Physical Dimensions
Figure 2: Module Dimensions (Front: 95mm H x 50mm W x 34mm D; Side: 32mm H)
2.2 Mounting
The CWT-BSR modules can be installed using either DIN rail mounting or screw fixing methods, providing flexibility for various industrial enclosures and setups.
2.3 Power Supply
Ensure the module is powered correctly:
- General Modules: DC 9-48V
- Analog Modules: DC 12-48V
2.4 Wiring Diagrams
Refer to the specific wiring diagrams below for your module type to ensure correct and safe connection of inputs, outputs, and communication lines.
2.4.1 CWT-BSR-DI40B (4 Digital Inputs)
Figure 3: CWT-BSR-DI40B NPN and PNP Digital Input Wiring
2.4.2 CWT-BSR-DO02B (2 Relay Outputs)
Figure 4: CWT-BSR-DO02B Relay Output Control for AC and DC Loads
2.4.3 CWT-BSR-IO22B (2 Digital Inputs, 2 Relay Outputs)
Figure 5: CWT-BSR-IO22B NPN/PNP Digital Input and AC/DC Relay Output Wiring
2.4.4 CWT-BSR-AD20B (2 Analog Inputs: 0-10V or 4-20mA)
Figure 6: CWT-BSR-AD20B 0-10V and 0-20mA Analog Input Internal Circuits
2.4.5 CWT-BSR-AD40B(V) / AD40B(A) (4 Analog Inputs: 0-10V or 0-20mA)
Figure 7: CWT-BSR-AD40B 0-10V and 0-20mA Analog Input Internal Circuits
2.4.6 CWT-BSR-DA02B (2 Analog Outputs: 0-10V)
Figure 8: CWT-BSR-DA02B 0-10V Analog Output Internal Circuit
2.4.7 CWT-BSR-AA02B (2 Analog Outputs: 0-20mA)
Figure 9: CWT-BSR-AA02B 0-20mA Analog Output Internal Circuit
2.4.8 CWT-BSR-TP20B (2 PT100 Inputs)
Figure 10: CWT-BSR-TP20B 3-wire and 2-wire PT100 Input Wiring
2.4.9 CWT-BSR-TD20B (2 K-type Thermocouple Inputs)
Figure 11: CWT-BSR-TD20B K-type Thermocouple Input Wiring
3. Operating Instructions
3.1 Communication Protocol
All CWT-BSR series modules utilize the MODBUS RTU protocol for communication. This standard protocol allows for easy integration with various industrial control systems.
3.2 Serial Port Parameters
Configure your communication device (PLC, HMI, PC) with the following serial port settings:
| Parameter | Value |
|---|---|
| Port Type | 1x RS485 & 1x RS232 |
| Baud Rate | 1200 ~ 115200 bps (Default: 9600 bps) |
| Parity | Even, Odd, None |
| Start Bit | 1 bit |
| Data Bits | 8 bits |
| Stop Bits | 1, 2 bits |
| Protocol | MODBUS RTU |
| Default Settings | 9600, N, 8, 1 (Slave ID: 1) |
3.3 Response Time
- At 9600 bps: 15ms
- At 115200 bps: 3ms
4. Maintenance
To ensure the longevity and reliable operation of your CWT-BSR module, follow these general maintenance guidelines:
- Keep the module clean and free from dust and debris.
- Regularly inspect all wiring connections for tightness and signs of corrosion.
- Ensure the operating environment adheres to the specified temperature and humidity ranges.
- Avoid exposing the module to excessive vibration or physical shock.
5. Troubleshooting
If you encounter issues with your CWT-BSR module, consider the following:
- No Power: Verify the power supply voltage is within the specified range (DC 9-48V or DC 12-48V for analog modules) and connections are secure.
- Communication Failure:
- Check serial port parameters (baud rate, parity, data bits, stop bits) match the module's settings.
- Ensure RS485/RS232 wiring is correct (A/B polarity for RS485).
- Verify the slave ID is correctly configured in your master device.
- Check for bus termination resistors if using RS485 over long distances or with multiple devices.
- Incorrect Readings/Outputs:
- Inspect input/output wiring for shorts, open circuits, or incorrect connections.
- For analog modules, ensure the input type (0-10V or 4-20mA) is correctly selected via jumpers if applicable.
- Verify sensor calibration and functionality.
- Module Not Responding: Power cycle the module. If the issue persists, contact technical support.
6. Specifications
6.1 Model Overview
Figure 12: CWT-BSR Series Model List with IO Ports and Communication Ports
6.2 General System Parameters
| Parameter | Specification |
|---|---|
| Power Supply | DC 9-48V (Analog modules: DC 12-48V) |
| Protection | IP20 |
| Installation | DIN rail mounting or screw fixing |
| Working Environment | -40℃ ~ 70℃, 5% ~ 85% RH (non-condensing) |
6.3 Module-Specific Specifications
Refer to the detailed wiring diagrams in Section 2.4 for specific input/output types, ranges, precision, and load capacities for each module variant.
- CWT-BSR-DI40B: 4 channels digital input, 12-24VDC input type.
- CWT-BSR-DO02B: 2 channels relay output (NO), 250V / 2A load, <20ms response time.
- CWT-BSR-IO22B: 2 channels digital input (12-24VDC) and 2 channels relay output (NO), 250V / 2A load, <20ms response time.
- CWT-BSR-AD20B: 2 channels analog input (0-10V or 4-20mA), 0.1% precision, 12-bit.
- CWT-BSR-AD40B(V): 4 channels analog input (0-10V), 0.1% precision, 12-bit.
- CWT-BSR-AD40B(A): 4 channels analog input (0-20mA), 0.1% precision, 12-bit.
- CWT-BSR-DA02B: 2 channels analog output (0-10V), 0.1% precision, 12-bit.
- CWT-BSR-AA02B: 2 channels analog output (0-20mA), 0.1% precision, 12-bit.
- CWT-BSR-TP20B: 2 channels PT100 input, -200℃ ~ 600℃ temperature range, 0.1 resolution.
- CWT-BSR-TD20B: 2 channels K-type thermocouple input, -270℃ ~ 1370℃ temperature range, 0.1 resolution.
7. User Tips
- For detailed Modbus register maps and communication commands, please refer to the comprehensive PDF user manual provided by the manufacturer. This document contains critical information for advanced configuration and integration.
- Always double-check your wiring before applying power to prevent damage to the module or connected equipment.
- When setting up communication, ensure the slave ID is unique on the Modbus network.
8. Warranty and Support
For warranty information, technical support, or further assistance, please contact your seller or the manufacturer directly. Ensure you have your product model and purchase details available.
A comprehensive user manual in PDF format is available for download, which includes detailed Modbus parameters and advanced configuration guides. You can access it here: CWT-BSR Series User Manual (PDF).