Comprehensive Product Summary – TRP-C37M Modbus TCP to RTU/ASCII Gateway with Watchdog

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### 1. Product Overview

Product Name: TRP-C37M
Model: TRP-C37M
Series: TRP-C Industrial Communication Gateway Series
Article Number: TRP-C37M
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-C37M is an industrial-grade Modbus TCP to RTU/ASCII gateway designed for reliable serial-to-Ethernet communication in harsh environments. It serves as a bridge between Modbus TCP networks and Modbus RTU/ASCII serial devices, supporting multiple operation modes and robust protection features. The device integrates a hardware watchdog, surge and overcurrent protection, and a power detection circuit to ensure continuous operation and automatic recovery from system or power failures.

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### 2. Key Features

- Multi-Protocol Gateway: Converts Modbus TCP to Modbus RTU or ASCII, supporting both TCP Master-to-Serial Slave and TCP Slave-to-Serial Master configurations.
- Flexible Operation Modes: Operates in Direct IP Mode, Virtual COM Mode, and Paired Mode for diverse network topologies.
- High Reliability: Built-in watchdog timer automatically resets the system in case of software or power failure.
- Industrial Protection: Surge, overcurrent, and overvoltage protection on RS-422/485 lines; ±15 kV ESD protection on serial interfaces.
- Wide Power Input Range: Accepts DC +10V to +30V via screw terminal or DC jack.
- Auto-MDIX Ethernet Port: Supports 10/100 Mbps auto-detecting Ethernet with automatic crossover correction.
- High-Speed Serial Communication: Baud rates from 1200 to 921,600 bps with hardware-based RS-485 direction control.
- Multi-Client Connectivity: Supports up to 16 simultaneous TCP client connections in server mode.
- Heart Beat Function: Periodic connection check ensures communication reliability and automatic reconnection after network or power interruptions.
- Easy Configuration: Configurable via DSM utility, web interface, or serial console; firmware upgradable via LAN.
- Compatibility: Works with Modscan32, Modbus Poll, CAS Modbus Scanner, SCADA systems, and Trycom’s TRPCOM utility.
- External Reset Switch: Allows quick restoration to factory defaults in case of configuration or password loss.
- Dual Power Input Options: Selectable between screw terminal and DC jack (5.5 × 2.1 mm plug).

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### 3. Technical Specifications

Power Input: DC +10V to +30V
Power Consumption: 12V / 140 mA
LAN Interface: Auto-MDIX, 10/100 Mbps auto-detecting Ethernet
Serial Interfaces:
- RS-232: TX, RX, RTS, CTS, DTR, DSR, DCD, GND
- RS-422: Differential 4-wire full-duplex (TX+, TX–, RX+, RX–)
- RS-485: Differential 2-wire half-duplex (DATA+, DATA–)
Baud Rate: 1200, 2400, 4800, 9600, 19200, 38400, 57600, 115200, 921600 bps
Data Bits: 5, 6, 7, or 8
Parity: None, Even, Odd
Stop Bits: 1, 1.5, or 2
Flow Control: Xon/Xoff, Hardware (RTS/CTS), None
Protocols Supported: TCP, IP, ARP, DHCP, Telnet, HTTP, UDP, ICMP
Modbus TCP Types:
- TCP Master to Serial Slave
- TCP Slave to Serial Master (up to 8 TCP ports, UID range 1–64)
Maximum TCP Connections: 16 clients
Serial Interface Protection: ±15 kV ESD; surge, overcurrent, and overvoltage protection
Terminal Wiring: Plug-in screw terminal, accepts AWG #12–30 wires
Indicators:
- PWR LED (system ready)
- LINK LED (Ethernet activity)
- TX/RX LEDs (UART transmit/receive)
Operating Temperature: –10°C to +65°C
Humidity: 0–90% non-condensing
Dimensions: 151 mm (L) × 75 mm (W) × 26 mm (H)
Weight: 395 g (with packaging)
Enclosure: Industrial-grade metal housing

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### 4. Functionality

The TRP-C37M functions as a communication gateway that translates Modbus TCP messages from Ethernet networks into Modbus RTU or ASCII serial protocols and vice versa. It supports three primary operation modes:

1. Direct IP Mode:
- Enables direct TCP/IP communication between a host and serial device.
- Suitable for Modbus TCP Master to Serial Slave or TCP Slave to Serial Master applications.

2. Virtual COM Mode:
- Creates virtual serial ports on a PC, mapping them to the TRP-C37M over TCP/IP or UDP.
- Allows legacy serial applications to communicate over Ethernet as if connected locally.
- Supports up to 16 simultaneous virtual COM connections.

3. Paired Mode (Bridge Mode):
- Two TRP-C37M units form a transparent serial bridge over Ethernet.
- Ideal for replacing long serial cables with Ethernet links.

Use Cases and Applications:
- Industrial automation and control systems
- SCADA and HMI integration
- Remote monitoring of Modbus RTU/ASCII devices
- Serial device networking and data acquisition
- Energy management and building automation systems

Compatibility:
Fully compatible with Modscan32, Modbus Poll, CAS Modbus Scanner, Modbus Slave, and Trycom’s TRPCOM utility. Supports Windows 98 through Windows 8 for Virtual COM drivers.

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### 5. Components & Accessories

Included Components:
- TRP-C37M Gateway Unit
- User Manual (Printed, Rev. 1.3)
- Support CD containing DSM utility, Virtual COM software, TRPCOM test utility, and console tools

Connectors:
- Ethernet Port: RJ45, Auto-MDIX
- Power Input: Screw terminal or DC jack (5.5 × 2.1 mm)
- Serial Ports:
- DB-9 male connector for RS-232
- Plug-in screw terminal for RS-422/485

Optional Accessories:
- DC power adapter (10–30V)
- Ethernet cable (straight or crossover)
- RS-232 null modem cable
- RS-422/485 wiring harness

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### 6. Installation & Setup

Power Connection:
Connect either the DC jack or screw terminal to a DC power source (10–30V). Do not use both simultaneously. The PWR LED will blink when the system is ready.

Network Connection:
Connect the Ethernet port to a LAN or PC using a standard RJ45 cable. The LINK LED indicates active connection. Auto-MDIX allows use of either straight-through or crossover cables.

Serial Connection:
- RS-232: Use a null modem cable for PC connection or straight-through cable for DCE devices.
- RS-422/485: Connect via screw terminal; supports AWG #12–30 wires.

DIP Switch Configuration:
- OFF/OFF: Direct IP Mode, RTU protocol
- ON/OFF: Virtual COM or Paired Mode
- OFF/ON: Direct IP Mode, ASCII protocol
- ON/ON: Restore Factory Defaults

Configuration Methods:
1. TRP-C37X DSM Utility:
- Detects devices on LAN, configures parameters, upgrades firmware, and saves settings.
2. Web Server Interface:
- Access via browser using device IP (default 192.168.1.1).
3. Serial Console:
- Configure via DB-9 port using console.exe utility.

Firmware Upgrade:
Performed through DSM utility or web interface via LAN connection.

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### 7. Performance & Capabilities

- Serial Performance: Up to 921,600 bps baud rate with hardware-controlled RS-485 direction switching.
- Network Performance: 10/100 Mbps Ethernet with automatic detection and correction.
- Connection Capacity: Supports up to 16 simultaneous TCP client connections in server mode.
- Reliability Features:
- Watchdog timer for automatic system recovery.
- Power detection circuit prevents boot failure under unstable voltage.
- Heart Beat function monitors connection integrity (port 5300, 5-second interval).
- Auto-reconnection after power or Ethernet failure.
- Latency & Throughput: Optimized for low-latency Modbus communication; configurable transmit timer (0–500 ms).
- Limitations:
- Only one power input method (DC jack or terminal) should be used at a time.
- UID range limited to 1–64 for TCP Slave to Serial Master mode.

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### 8. Standards & Compliance

Communication Standards:
- Modbus TCP, Modbus RTU, Modbus ASCII
- Ethernet IEEE 802.3 10/100Base-T
- TCP/IP, UDP, DHCP, ARP, ICMP, HTTP, Telnet

Electrical & Environmental Compliance:
- ESD Protection: ±15 kV on serial interfaces
- Surge/Overcurrent/Overvoltage Protection: RS-422/485 lines
- Operating Temperature: –10°C to +65°C
- Humidity: 0–90% non-condensing

Software Compatibility:
- Virtual COM drivers for Windows 98, 2000, XP, Vista, 2003, 7, and 8
- Compatible with major Modbus diagnostic and SCADA tools

Industry Standards:
- Designed for industrial automation and control environments
- Complies with Modbus Organization specifications for TCP/RTU/ASCII interoperability

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### 9. Additional Information

Warranty:
Standard manufacturer warranty (details available from Trycom Technology Co., Ltd.).

Support & Maintenance:
- Technical support via Trycom website and email.
- Firmware updates available through LAN using DSM utility or web interface.
- Configuration backup and restore supported via DSM utility.

Maintenance Recommendations:
- Ensure stable DC power supply within 10–30V range.
- Avoid simultaneous use of DC jack and screw terminal inputs.
- Periodically check Ethernet and serial connections for secure fit.
- Use surge-protected power sources in high-interference environments.

Software Tools Provided:
- TRP-C37X DSM Utility: Device discovery, configuration, and firmware management.
- Virtual COM Utility (VCOMM): Creates virtual serial ports for networked communication.
- TRPCOM Utility: Diagnostic and loopback testing for RS-232/422/485 interfaces.
- Console Utility: Serial-based configuration tool for low-level setup.

Firmware & Updates:
Firmware can be upgraded via LAN; configuration can be saved to EEPROM or external log files.

Documentation:
User’s Manual (Rev. 1.3, April 2014) provides detailed installation, configuration, and application examples.

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### Summary

The Trycom TRP-C37M Modbus TCP to RTU/ASCII Gateway is a robust, industrial-grade communication bridge engineered for seamless integration between Ethernet-based Modbus TCP networks and serial Modbus RTU/ASCII devices. With its wide power input range, advanced protection circuitry, and flexible configuration modes, it ensures reliable operation in demanding industrial environments. The inclusion of a hardware watchdog, heart beat monitoring, and automatic reconnection mechanisms make it ideal for mission-critical automation systems requiring continuous uptime.

Its compatibility with standard Modbus tools, support for up to 16 simultaneous TCP clients, and comprehensive configuration utilities make the TRP-C37M a versatile and dependable solution for industrial communication, SCADA integration, and remote device management.