Woodward 9907-028

Product Category: Protocol Gateway / Serial-to-Ethernet Converter
Function: Bidirectional protocol translation — W-Net ↔ Modbus RTU ↔ Modbus TCP/IP
Communication Interfaces:

• Port 1 (Governor Side): RS-485, W-Net proprietary protocol, 4-wire shielded twisted pair, 9600–115200 baud
• Port 2 (Serial Side): RS-485, Modbus RTU, 4-wire shielded twisted pair, 9600–115200 baud
• Port 3 (Ethernet Side): 10/100 Base-TX, RJ-45, Modbus TCP/IP server and client
  Supported Protocols: W-Net (Woodward proprietary), Modbus RTU (Master/Slave), Modbus TCP/IP (Server/Client)
  Data Points Supported: Governor speed, load, fuel valve position, temperature, pressure, alarm status, operating mode, setpoints, event logs, diagnostics

Data Update Rate (Serial): Configurable from 100 ms to 2000 ms (default 250 ms)
Data Update Rate (Ethernet): Configurable from 100 ms to 5000 ms (default 500 ms)
Maximum Simultaneous Modbus TCP/IP Clients: 8 connections
Modbus Register Range: Holding registers 40001–49999, Coils 00001–09999, Discrete Inputs 10001–19999, Input Registers 30001–39999
Baud Rate Options: 9600, 19200, 38400, 57600, 115200 bps (configurable per port)
Response Time (Serial): Less than 20 ms (typical)
Response Time (Ethernet): Less than 50 ms (typical)
Packet Size (Modbus TCP/IP): Up to 1024 bytes per transaction

Operating Temperature Range: 0°C to +60°C (32°F to +140°F)
Storage Temperature Range: -40°C to +85°C (-40°F to +185°F)
Ambient Humidity: 5% to 95% RH, non-condensing
Altitude: Up to 3000 m (9842 ft) above sea level
Vibration: 5 g, 10–500 Hz (operating); 10 g, 10–500 Hz (survival)
Shock: 30 g, 11 ms half-sine
Ingress Protection: IP20 (indoor use only, panel-mounted)
EMC Compliance: EN 61000-6-2 (industrial environment), EN 61000-6-4 (emission)

Housing Material: ABS plastic (UL 94 V-0 rated) — flame retardant
Front Panel: Polycarbonate lens with 5 LED status indicators
PCB Material: FR-4, conformal coated
Connector (Ethernet): RJ-45, gold-plated contacts, shielded, with integrated magnetics
Connector (Serial Port 1): RJ-45, 8P8C, shielded, W-Net to governor
Connector (Serial Port 2): RJ-45, 8P8C, shielded, Modbus RTU to SCADA/PLC
Terminal Block (Power): Screw-clamp, tin-plated brass, 2 positions (24 VDC input)
Grounding Terminal: Dedicated earth terminal, green/yellow, 4 mm² minimum wire size
Mounting: DIN rail (35 mm, EN 60715) or panel mount with bracket
Dimensions (approximate): 120 mm × 95 mm × 35 mm (W × H × D)
Weight: Approximately 0.35 kg (0.77 lbs)

Structure:

• Compact rectangular enclosure with DIN rail mounting clips on top and bottom
• Front panel: 5 LED status indicators (Power ON, Ethernet Link, Serial 1 Active, Serial 2 Active, Fault/Alarm)
• Rear panel: 1 × RJ-45 Ethernet port, 2 × RJ-45 serial ports (Port 1: W-Net, Port 2: Modbus RTU), 1 × 2-pin screw-clamp terminal block (24 VDC power)
• Internal: Single multilayer PCB with dual RS-485 transceivers, Ethernet PHY with integrated magnetics, microprocessor (ARM Cortex-M4), 256 KB Flash, 64 KB RAM, isolation transformers (2×), and voltage regulator
• Labeling: Model number, serial number, IP address, MAC address, W-Net node address printed on rear label

Working Principle:
The 9907-028 contains a dual-port RS-485 interface and an Ethernet interface connected by an internal ARM Cortex-M4 microprocessor. On Port 1 (W-Net side), the module communicates with the Woodward EasyGen governor using the W-Net proprietary protocol over RS-485. The microprocessor continuously polls the governor for real-time data (speed, load, valve position, alarms) at the configured update rate (default 250 ms) and stores the data in an internal circular buffer (64 KB RAM). On Port 2 (Modbus RTU side), the module acts as a Modbus RTU slave, responding to read/write requests from a SCADA or PLC over RS-485. The microprocessor translates Modbus RTU register addresses into internal W-Net data points, reads the value from the buffer, and returns it in Modbus format. On Port 3 (Ethernet side), the module acts as a Modbus TCP/IP server, listening for TCP connections from up to 8 simultaneous clients. When a client sends a Modbus TCP/IP request, the microprocessor translates it into a Modbus RTU query, sends it to the governor via Port 1, receives the response, and returns the data to the Ethernet client in Modbus TCP/IP format. For write operations, the reverse translation occurs: Modbus TCP/IP write → Modbus RTU write → W-Net write command → governor executes. The two isolation transformers provide galvanic isolation (1500 V DC) between all three ports, preventing ground loops and protecting the governor from network transients.

Key Features:

• Triple-protocol support on one module — W-Net, Modbus RTU, Modbus TCP/IP simultaneously
• 8 simultaneous Modbus TCP/IP clients — multiple SCADA stations access the governor without additional hardware
• Dual RS-485 ports with independent configuration — W-Net and Modbus RTU run at different baud rates if required
• Built-in web server — browser-based configuration and real-time data dashboard
• Galvanic isolation (1500 V DC) on all three ports — eliminates ground loops and protects against surges
• ARM Cortex-M4 processor with 256 KB Flash — fast data processing, large buffer for event logging
• Firmware updatable over Ethernet or serial — no physical access required for software upgrades
• 5 LED status indicators — Power, Ethernet Link, W-Net Active, Modbus RTU Active, Fault (visual diagnostics)

Advantages:

• Eliminates need for separate serial-to-Ethernet converters — all three protocols on one compact module
• 8 simultaneous Ethernet clients — supports large SCADA systems with multiple operator stations
• Independent baud rate configuration per serial port — W-Net at 115200 bps and Modbus RTU at 9600 bps simultaneously
• Dual isolation transformers — maximum protection for the governor from both serial and Ethernet side faults
• Web-based configuration — no software installation; configure from any browser on the network
• Large 64 KB RAM buffer — stores up to 10,000 data points for historical trending and event logging
• Firmware-upgradable remotely — reduces service calls; update from anywhere on the network
• Compact DIN rail form factor (35 mm) — fits in standard control panels without additional space

Applicable Industries:

• Power Generation — gas turbine governor remote monitoring, steam turbine control, diesel generator sets, cogeneration plants
• Oil & Gas — remote monitoring of generator drives on offshore platforms, pipeline compressor stations, wellhead power systems
• Mining — remote governor monitoring for mine power generation in inaccessible underground locations
• Marine — shipboard generator control and remote monitoring from bridge or engine room
• Data Centers — UPS and backup generator remote management via Modbus TCP/IP to DCIM
• Commercial Buildings — cogeneration plant integration with building automation via Modbus TCP/IP to BMS
• Industrial Plants — remote monitoring of standby generators in manufacturing facilities, refineries, and chemical plants
• Water / Wastewater — pump station generator remote monitoring via Modbus RTU to SCADA

Model Series:

Compatible Governors:

Installation Requirements:

• Mount the gateway on a standard 35 mm DIN rail (EN 60715) in the control panel
• Connect the 24 VDC power supply to the 2-pin screw-clamp terminal block on the rear panel (polarity: positive to +, negative to −)
• Connect the Ethernet cable (shielded CAT5e or CAT6) from the gateway RJ-45 port to the plant Ethernet switch
• Connect the W-Net serial cable (RS-485, 4-wire shielded twisted pair) from Port 1 (RJ-45) to the governor’s communication port (J4 or J5) — use blue-sheathed IS cable if routing through hazardous area
• Connect the Modbus RTU serial cable (RS-485, 4-wire shielded twisted pair) from Port 2 (RJ-45) to the SCADA/PLC Modbus RTU port
• Set the gateway IP address via the built-in web server (default: 192.168.1.100) or via governor front panel menu
• Configure the Modbus register mapping in the SCADA/DCS system to match the gateway’s register table (Document 9907-REG-001)
• Ground the gateway chassis to the panel earth bar using the dedicated grounding lug (4 mm² green/yellow wire minimum)
• Verify Power LED is green, Ethernet Link LED is green, and W-Net Active LED is flashing after power-up

Usage Precautions:

• Do not connect the gateway to the Ethernet network before configuring its IP address — IP conflict will cause communication failure with all devices
• Do not exceed 8 simultaneous Modbus TCP/IP connections — additional connections will be rejected
• Do not use unshielded Ethernet cable — EMI from VFDs, motors, and welders will corrupt data in industrial environments
• Do not connect the W-Net serial cable in parallel with other RS-485 devices — W-Net is point-to-point only; daisy-chaining causes communication errors
• Do not connect the Modbus RTU cable in parallel with more than 32 Modbus devices — RS-485 specification limits load to 32 unit loads
• Do not apply voltage exceeding 32 VDC to the power input — this will damage the internal voltage regulator and microprocessor
• Do not expose the gateway to temperatures above +60°C — internal components are rated for a maximum of +60°C
• Do not disable the built-in web server firewall — leaving the web interface unprotected exposes the governor to unauthorized access
• Set a strong password on the web interface — the default password (woodward) must be changed during initial commissioning
• Perform firmware updates only from Woodward-approved sources — unauthorized firmware can brick the module
• Verify register mapping in the SCADA system matches the gateway documentation — mismatched registers cause incorrect data display
• Do not mix W-Net and Modbus RTU cables on the same RS-485 bus — each port is a separate, isolated bus

Certifications:

• CE Marked (EMC Directive 2014/30/EU, Low Voltage Directive 2014/35/EU, Machinery Directive 2006/42/EC)
• UL Listed (File E211762) — for use in North American control panels
• CSA Certified (File LR42403)
• RoHS Compliant (Directive 2011/65/EU)
• REACH Compliant (Regulation EC 1907/2006)
• WEEE Compliant (Directive 2012/19/EU)
• ATEX / IECEx (when used with IS-rated cable in hazardous areas) — Zone 1 / Zone 2 gas, Zone 20 / Zone 21 dust

Documentation Reference:

• Woodward 9907 Series Gateway Module Installation Manual (Document 9907-IM-001)
• Woodward 9907 Series Technical Data Sheet (Document 9907-TDS-001)
• Woodward 9907 Modbus Register Map (Document 9907-REG-001)
• Woodward 9907 Web Configuration Guide (Document 9907-WEB-001)
• Woodward EasyGen Governor Communication Guide (Document EG-COM-001)
• Woodward Gateway Module Selection Guide (Document 9907-SG-001)

Replacement Parts: