9907-031 723 Digital Speed Control Module | Woodward

Configured for reciprocating engine velocity regulation in generator applications, the Woodward 9907-031 (9907-031 Digital Speed Control) provides direct physical/electrical execution of MPU/proximity signal acquisition and actuator drive control.

Hardware Specifications

Actuator Loop Feedback Response

The 9907-031 control module employs digital signal processing to regulate engine speed and load distribution in paralleled generator systems. The unit features two dedicated speed sensor inputs compatible with either passive MPU or active proximity switches, ensuring precise rotational velocity feedback. To ensure a stable actuator loop feedback response, the controller generates high-current drive signals via four configurable analog outputs (two 0-1/4-20 mA and two 0-20/0-200 mA channels). These outputs are mapped to the fuel actuator to maintain frequency stability. Furthermore, the unit is compatible with the Woodward DSLC Digital Synchronizer and Load Control platform, enabling seamless integration of load-sharing inputs to optimize engine performance across transient load conditions.

Frequently Asked Questions

Q: How is the module programmed for specific engine requirements?

A: The 9907-031 is configured using a Woodward Hand Held Programmer or an external ASCII character terminal connected via the RS-422 serial port. Parameters are stored in non-volatile memory to maintain settings during power loss.

Q: Is this module capable of driving high-current fuel actuators?

A: Yes, the 9907-031 features high-range analog outputs capable of delivering up to 200 mA. Users must ensure that the actuator coil resistance matches the output impedance of the assigned analog channel to prevent thermal stress on the module driver stages.

Field Installation Guidelines

1. Mounting: Secure the 723 series chassis within an industrial control cabinet. Due to the 40 W power dissipation, ensure adequate ventilation gaps are maintained around the 41.28 x 29.21 x 6.04 cm enclosure to remain within the -40 to 70 deg C thermal envelope.
2. Signal Wiring: Connect MPU and proximity probes using shielded twisted-pair wiring. Terminate shields at the cabinet ground bus to minimize electromagnetic noise and ensure the integrity of the actuator loop feedback response.
3. Power Connection: Verify the 18-40 VDC input range. Use an isolated DC power supply to mitigate noise from the engine cranking cycle or secondary power systems.
4. Validation: Perform a calibration check of all analog I/O using the serial terminal interface. Confirm that the speed signal frequency matches the engine's mechanical RPM before finalizing the governor tuning for the generator set.