Woodward Safety Systems

    Safety System for Industrial Applications


    SIL-3 MicroNet Safety Module

    Woodward’s MicroNet Safety Module PLC can be applied to any size steam, gas, or hydro turbine, or plant process equipment. This safety PLC's fast (12 millisecond) response time, 0.5 to 32 000 rpm speed range, and integrated overspeed and acceleration detection/protection functionality, make it ideal for application on critical high-speed rotating motors, compressor, turbines or engines.


    • The MSM is IEC61508 SIL-3 Certified and API670 & API612 Compliant.


     Learn more from the MicroNet Safety Module product specification


    High Resolution Displays

    • Each module includes a high resolution 4.2” (107 mm) color display and keypad to allow users to locally monitor configuration settings, statuses, system inputs and outputs, and alarm, trip, and overspeed logs.

    Automatic Overspeed Test Routine

    • Optionally, the MSM can be configured to routinely perform and overspeed test each module/trip solenoid, then log and report the test results. With this test routine, each module is sequenced through its test sequence using an internal frequency generator to emulate an overspeed condition.

    Automatic Test Routines

    • Optionally, the MSM can be configured to routinely perform custom tests of each module/trip solenoid, then log and report the test results. With this test routine, each module is sequenced through a programmed test sequence to simulate, test, and log the results of each safety even condition.

    Acceleration/Deceleration Detection

    • Optionally, the MSM can be configured to protect a turbine from high acceleration/deceleration events. The derivative of the speed signal is used to detect turbine acceleration/deceleration and issue an associated trip command.

    MPU Detection

    • Each module’s speed sensor input uses special MPU open-wire detection circuitry to validate that the MPU is properly connected before turbine operation, and special loss-of-speed detection logic to validate MPU functionality during turbine operation.

    Sulfur Contamination Resistant

    • Utilizes special conformal coating material that has demonstrated excellent long-term protection against H2S and SO2 gases at levels classified in international standard IEC 721-3-3 1994 - environment Class 3C2 


    • The MSM functions as a safety PLC, as it accepts 10 discrete or analog inputs per module (30 total), and allows users to create custom safety/protection programs to safely protect site personnel and equipment. Programmers are able to utilize typical logic and testing sequence routines to create their application-specific safety logic and tests.

    On-Line Testing

    • Each MSM module can be tested manually from the module’s front panel, Modbus communications port, or automatically via its auto-test routine function. The MSM allows users to configure overspeed or custom-programmed tests to be performed manually or automatically on a periodic basis. With these test routines, each module (A, B, C) is tested one at a time, and either a successful test result is logged or, upon sensing a fault, the routine is halted and the sensed fault indicated/alarmed.

    On-Line Repair

    • The MSM’s triple modular design allows users to easily replace one of its modules (A, B, C) while the monitored equipment/turbine is on-line and operating normally. Ease of replacement is enhanced by the unit’s backplane plug-and-operate structure, and its module-to-module learning function.

    Trip, Alarm, & Overspeed Logs

    • The MSM log function logs (saves to memory) all trips, alarms, trip valve response times, and overspeed events. The trip log function uses a scrolling buffer and records the last 50 sensed trip or alarm events and the last 20 overspeed events to memory, with associated times. Each log file can be viewed from the unit’s front panel, or downloaded to a computer via the MSM service tool program. Each module utilizes nonvolatile memory to ensure that all logged events are saved, even on loss of power.

    Real Time Clock

    • Each MSM module utilizes a real-time-clock to ensure accurate time logging. A special time averaging function is utilized between modules to ensure module-to-module clock synchronization. Alternatively one of the MSM’s inputs can be configured to accept a discrete clock synchronization input signal from a plant DCS or other time synch device.

    North American Compliance:

    • CSA Certified for Class I, Division 2, Groups A, B, C, and D, T3 at 60 °C Ambient for use in Canada and the United States

    European Compliance:

    • EMC Directive: 2004/108/EC
    • ATEX Directive: 94/9/EC Zone 2, Category 3, Group II G, Ex nA II T3

    Other International Compliance:

    • TÜV certified for SIL-3 per IEC 61508 Parts 1-7, Function Safety of Electrical / Electronic / Programmable Electronic
    • Safety Related Systems

    Other Compliance:

    • IEC60068-2-60:1995 Part 2.60 Methods 1 and 4 (conformal coating)
    • API670 & API612 compliant
    • RoHS Exempt per Annex IA of Directive 2002/96/EC referring to "monitoring and control instruments" within the meaning of
    • Category 9

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