Comprehensive Product Summary – TRP-C28H Isolated 4 DI and 4 AC Relay Modbus TCP Module (Pair Mode)

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### 1. Product Overview

Product Name: TRP-C28H
Model: TRP-C28H
Series: TRP-C Industrial Ethernet I/O Series
Article Number: TRP-C28H
Manufacturer: Trycom Technology Co., Ltd.
Manufacturer Address: No. 35, Zhongxing Rd., Guishan Township, Taoyuan County 333, Taiwan
Contact: Tel: +886-3-350-3351 | Fax: +886-3-350-3352
Website: [www.trycom.com.tw](http://www.trycom.com.tw)

The Trycom TRP-C28H is an isolated digital input and AC relay output Modbus TCP module designed for industrial automation, remote monitoring, and control applications. It integrates 4 optically isolated digital input channels with counter functionality and 4 AC relay output channels, supporting Modbus TCP, Modbus RTU/ASCII, and TRP-ASCII protocols. The device can operate independently or in pair mode, allowing two TRP-C28H units to communicate directly over Ethernet without additional software or drivers.

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### 2. Key Features

- 4 Isolated Digital Inputs and 4 AC Relay Outputs:
Provides four optically isolated digital input channels (±0–30V DC) and four relay outputs rated up to 5A/250V AC.

- Multi-Protocol Support:
Automatically detects and supports TRP-ASCII, Modbus RTU, and Modbus ASCII communication protocols for flexible integration.

- Ethernet Connectivity:
Equipped with an RJ45 Ethernet interface supporting Modbus TCP/IP and Virtual-COM operation modes.

- Pair Mode Operation:
Enables direct remote control between two TRP-C28H modules without PC or software intervention.

- Web-Based Configuration:
Built-in web server allows configuration and monitoring via any web browser on PC, tablet, or smartphone.

- High Isolation and Reliability:
Optical isolation of 3750 Vrms on digital inputs and 4000V surge strength on relays ensures robust operation in harsh industrial environments.

- Watchdog and Heartbeat Functions:
Built-in watchdog prevents system hang-ups; heartbeat function maintains reliable TCP communication by sending periodic keep-alive signals.

- Flexible Power Input:
Accepts DC +10V to +30V via screw terminal or DC jack (5.5×2.1 mm).

- Auto-MDIX Ethernet Port:
Supports automatic crossover detection and correction for simplified network cabling.

- LED Indicators:
Power, link, and individual I/O channel status LEDs provide clear visual feedback.

- DIN-Rail and Panel Mounting:
Supports both mounting options for versatile installation in control cabinets or panels.

- Firmware Upgradeable:
Firmware can be updated via the Internet or Trycom Device Manager utility.

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### 3. Technical Specifications

| Parameter | Specification |
|----------------|-------------------|
| Power Input Voltage | DC +10V to +30V |
| Power Consumption | 320 mA @ 12V DC |
| Communication Interface | Ethernet RJ45 (Auto-MDIX) |
| Supported Protocols | TRP-ASCII, Modbus RTU, Modbus ASCII, Modbus TCP |
| Digital Inputs | 4 optically isolated channels |
| Input Voltage Range | ±0 to 30V DC |
| Input Logic Level 0 | ≤ +1V |
| Input Logic Level 1 | +4.0V to +30V |
| Input Isolation Voltage | 3750 Vrms |
| Input Counter Range | 0–65535 counts per channel |
| Relay Outputs | 4 channels (2 Form A: RL1, RL2; 2 Form C: RL3, RL4) |
| Relay Contact Rating | 5A @ 30V DC / 120V AC / 250V AC |
| Relay Surge Strength | 4000V |
| Relay Operating Time | 3 ms |
| Relay Mechanical Life | 2 × 10⁷ operations |
| TCP Connections | Up to 16 simultaneous connections |
| Module ID Range | 1–255 |
| Heartbeat Interval | Every 5 seconds |
| Operating Temperature | 0°C to +50°C |
| Storage Temperature | -10°C to +70°C |
| Humidity | 10–90% RH (non-condensing) |
| Dimensions | 151 mm (L) × 75 mm (W) × 26 mm (H) |
| Weight | 395 g |
| Mounting Options | DIN-rail or panel mount |
| Connection Type | Screw terminal (max AWG 12 wire) or DC jack |
| Indicators | Power, Link, 8-channel I/O LEDs |

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### 4. Functionality

The TRP-C28H functions as a network-based digital I/O controller. It converts digital input signals into Modbus TCP or TRP-ASCII data packets for transmission over Ethernet networks. The module can also receive Modbus commands to control its relay outputs.

Use Cases and Applications:
- Industrial automation and process control
- Remote monitoring and control systems
- Building management and HVAC systems
- SCADA and data acquisition networks
- Machine status monitoring and alarm signaling
- Energy management and smart grid integration

Operation Modes:
1. Modbus TCP Server Mode:
Communicates with up to 16 Modbus TCP clients simultaneously.
2. Virtual-COM Mode:
Emulates a serial COM port over Ethernet for legacy software compatibility.
3. Pair Mode:
Two TRP-C28H units can be configured to mirror input and output states directly over the network.

Compatibility:
Compatible with Modbus software such as Modscan32, Modbus Poll, CAS Modbus Scanner, and SCADA systems.

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### 5. Components & Accessories

Included Components:
- TRP-C28H main module
- User manual (Rev. 1.1, Sep. 2013)
- Software CD containing DSM Utility, TRPCOM test utility, and Virtual-COM driver
- Mounting hardware for DIN-rail or panel installation

Optional Accessories:
- DC power adapter (10–30V DC output)
- Ethernet RJ45 cable
- Screw terminal connectors (AWG 12 max)

Connectors:
- Ethernet Port: RJ45 (Auto-MDIX)
- Power Input: Screw terminal or DC jack (5.5×2.1 mm)
- I/O Terminals: Screw terminals for DI0–DI3 and RL1–RL4 connections

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### 6. Installation & Setup

Installation Steps:
1. Power Connection:
Connect a DC power source (10–30V) to the screw terminal or DC jack. The PWR LED will blink to indicate readiness.
2. Network Connection:
Connect the RJ45 Ethernet port to a LAN switch, router, or PC. The LINK LED will illuminate when connected.
3. I/O Wiring:
Wire digital inputs and relay outputs according to the terminal pin assignments.
4. Configuration:
Configure network and protocol parameters using either:
- Trycom Device Manager (DSM Utility)
- Built-in Web Server Interface

Configuration Options:
- Static or DHCP IP addressing
- Modbus slave ID (1–255)
- TCP port number and maximum connections
- Pair mode destination IP and port
- Watchdog enable/disable
- LED display control
- Power-on and safe-mode output states

Factory Reset:
Hold the external reset button while powering on until the power LED flashes to restore factory defaults.

Mounting:
Supports both DIN-rail and panel mounting. Ensure adequate ventilation and avoid simultaneous use of both power inputs.

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### 7. Performance & Capabilities

- High-Speed Communication:
Ethernet-based Modbus TCP ensures fast and reliable data exchange with minimal latency.

- Multi-Client Connectivity:
Supports up to 16 concurrent TCP connections, allowing multiple SCADA or HMI systems to access the same module.

- Counter Functionality:
Each digital input channel includes a 16-bit counter (0–65535) for event counting or pulse measurement.

- Relay Performance:
- Contact rating: 5A at 250V AC or 30V DC
- Operating time: 3 ms
- Mechanical endurance: 20 million operations

- Reliability Features:
- Watchdog Timer: Prevents system lock-up by resetting the module if communication fails.
- Heartbeat Function: Sends a keep-alive signal every 5 seconds to maintain TCP connection integrity.
- Auto-Reconnection: Automatically restores communication after power or network interruptions.

- Efficiency:
Low power consumption (320 mA @ 12V) and wide voltage tolerance (10–30V DC) make it suitable for energy-sensitive installations.

- Limitations:
- Operating temperature limited to 0–50°C.
- Not designed for direct outdoor exposure without enclosure protection.
- Relay outputs are mechanical; switching frequency should be managed to ensure longevity.

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### 8. Standards & Compliance

- Communication Standards:
- Modbus TCP/IP (IEEE 802.3 Ethernet)
- Modbus RTU/ASCII (EIA RS-485 compatible via Virtual-COM)
- TRP-ASCII proprietary protocol

- Electrical Isolation:
- Digital input isolation: 3750 Vrms
- Relay surge protection: 4000V

- Safety & EMC:
Designed for industrial environments with surge absorbers on each relay contact (N.C. and N.O.) and optical isolation for input protection.

- Regulatory Compliance:
Conforms to general industrial control equipment standards. (Manufacturer reserves the right to modify specifications for improved reliability.)

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### 9. Additional Information

Warranty:
Standard manufacturer warranty (duration as per Trycom policy). Covers defects in materials and workmanship under normal use.

Technical Support:
Trycom provides technical documentation, firmware updates, and software utilities via its website. Support is available through email and phone.

Maintenance:
- Periodically inspect wiring and terminal connections.
- Avoid simultaneous use of both power inputs.
- Keep the module in a dry, dust-free environment.
- Firmware updates can be applied using the DSM Utility or web interface.

Firmware & Software Tools:
- DSM Utility: For device discovery, configuration, and firmware upgrades.
- TRPCOM Test Utility: For debugging and command testing during software development.
- Virtual-COM Utility: Creates virtual serial ports for Modbus RTU communication over Ethernet.

Firmware Upgrade Procedure:
1. Launch DSM Utility.
2. Locate the TRP-C28H on the network.
3. Select “Upgrade” and choose the firmware file.
4. Follow on-screen instructions to complete the update.

Pair Mode Operation Example:
- Server Module: Configured with static IP (e.g., 192.168.1.1).
- Client Module: Configured to connect to the server’s IP and port.
- Once paired, input changes on one module trigger corresponding relay outputs on the other.

Environmental Considerations:
- Operating humidity: 10–90% non-condensing.
- Storage temperature: -10°C to +70°C.
- Ensure installation in a protected enclosure for outdoor or high-dust environments.

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### Summary

The Trycom TRP-C28H is a robust, network-enabled digital I/O module engineered for industrial automation and remote control applications. Combining 4 isolated digital inputs with counters and 4 high-voltage AC relay outputs, it provides seamless integration into Modbus TCP networks and supports multiple communication protocols for maximum flexibility.

Its pair mode capability allows direct device-to-device communication, eliminating the need for intermediary software or controllers. With features such as web-based configuration, watchdog protection, heartbeat monitoring, and auto-reconnection, the TRP-C28H ensures reliable, continuous operation in demanding environments.

Compact, durable, and easy to configure, the TRP-C28H is ideal for engineers and system integrators seeking a dependable Ethernet I/O solution for industrial control, monitoring, and automation systems.

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End of Product Summary – TRP-C28H Isolated 4 DI and 4 AC Relay Modbus TCP Module (Pair Mode)