Woodward 9905-968 Analog Input Module

Product Details

9905-968 Product Description

The Woodward 9905-968 is a 6-channel analog input module engineered for seamless integration within the Woodward 9905 control platform. Designed to serve as a precision signal acquisition layer in turbine, compressor, and generator control architectures, this module delivers stable, high-resolution analog signal conditioning across demanding industrial environments. Its role within the 9905 system extends far beyond simple signal conversion — it functions as a critical node in a layered control hierarchy that spans the I/O layer, control layer, communication layer, and power layer, ensuring that every analog measurement is accurately captured, conditioned, and transmitted to the central processing unit with minimal latency and maximum fidelity.

In modern industrial automation architectures, the integrity of analog signal acquisition directly determines the quality of closed-loop control. The Woodward 9905-968 addresses this requirement by providing six independent analog input channels, each capable of accepting standard process signals including 4–20 mA current loops and 0–10 V voltage inputs. The module's internal signal conditioning circuitry filters electrical noise, compensates for common-mode interference, and maintains channel-to-channel isolation, ensuring that signals from field-mounted sensors — including thermocouples, RTDs, pressure transmitters, and flow meters — are delivered to the 9905 CPU with the accuracy required for turbine speed governing, fuel control, and load sharing applications.

System architects deploying the Woodward 9905-968 benefit from its native compatibility with the 9905 backplane architecture. The module slots directly into the 9905 rack, sharing the internal communication bus with companion modules such as the Woodward 9905-838 digital output module, the 9905-867 analog output module, and the 9905-977 communication gateway. This tight integration eliminates the need for external signal converters or protocol bridges, reducing wiring complexity, minimizing potential failure points, and accelerating commissioning timelines on new installations. The shared backplane also enables the 9905 CPU — such as the Woodward 9905-001 or 9905-002 processor module — to perform coordinated, deterministic scan cycles across all I/O modules, a prerequisite for high-speed governor control and protective relay coordination.

From a redundancy design perspective, the 9905-968 supports deployment in simplex and redundant control architectures. In redundant configurations, paired 9905 CPU modules monitor each other's health status while sharing a common I/O bus, allowing the standby controller to assume control within milliseconds of a primary CPU fault. The analog input data acquired by the 9905-968 is simultaneously available to both the active and standby processors, ensuring bumpless transfer and continuous process visibility during controller switchover events. This architecture is particularly valuable in gas turbine control, steam turbine governing, and large reciprocating engine management, where even brief control interruptions can result in costly process upsets or equipment damage.

The module's diagnostic capabilities further enhance system maintainability. The 9905-968 performs continuous self-monitoring of channel integrity, detecting open-circuit conditions, out-of-range signals, and internal hardware faults. Diagnostic status is reported to the 9905 CPU via the backplane bus and can be surfaced through the Woodward Toolkit software environment, enabling maintenance engineers to identify and isolate faults without interrupting the control process. This capability integrates naturally with plant-level asset management systems through the 9905 communication gateway, supporting MODBUS RTU, MODBUS TCP, and proprietary Woodward communication protocols that connect the control system to DCS platforms, SCADA systems, and historian databases.

For facilities managing multi-unit installations — such as power plants operating multiple gas turbine generator sets or compressor stations with parallel compression trains — the 9905-968 provides a standardized analog input solution that simplifies spare parts management and reduces technician training requirements. A single module type covers the analog input requirements across multiple control panels, and the module's robust industrial design — rated for extended temperature ranges and high-vibration environments — ensures reliable operation in both indoor control rooms and outdoor enclosures. Companion components such as the Woodward 9905-518 power supply module, the 9905-791 terminal board, and the 9905-458 I/O expansion chassis further extend the system's capacity and flexibility without requiring changes to the core control software.

Installation and commissioning of the 9905-968 follow standard Woodward 9905 procedures. The module is inserted into the designated rack slot, secured with the front-panel locking mechanism, and automatically recognized by the 9905 CPU during the system initialization sequence. Channel assignments, scaling parameters, and alarm thresholds are configured through the Woodward Toolkit application, which provides a graphical interface for mapping physical input channels to control application variables. Factory acceptance testing, site acceptance testing, and loop calibration procedures are all supported within the Toolkit environment, reducing the time required to bring new installations into service and ensuring that all analog channels meet the accuracy specifications required by the control application.

Long-term operational reliability is supported by Woodward's established supply chain and the availability of the 9905-968 as a stocked replacement module. Facilities operating legacy 9905-based control systems can source replacement modules without the extended lead times associated with obsolete or discontinued components, minimizing the risk of extended outages caused by module failures. Each unit supplied by NANKMOS undergoes pre-shipment functional verification, including channel accuracy checks, isolation testing, and backplane communication validation, before dispatch. All modules are covered by a 12-Month Warranty, providing assurance of product quality and performance from the date of delivery.

The Woodward 9905-968 represents a proven, system-matched analog input solution for engineers and procurement specialists maintaining or expanding Woodward 9905-based control architectures. Its combination of multi-channel analog acquisition, native backplane integration, redundancy support, comprehensive diagnostics, and long-term parts availability makes it an essential component in the sustained operation of turbine, compressor, and generator control systems across the power generation, oil and gas, and industrial manufacturing sectors.

The 9905-968 operates as part of a fully integrated Woodward 9905 automation platform. In a typical turbine control panel, the module shares the 9905 rack with the Woodward 9905-001 CPU module, which executes the governor control application and coordinates all I/O scan cycles. The Woodward 9905-518 power supply module provides regulated DC power to the backplane, ensuring stable operation of the 9905-968 and all companion modules under varying load conditions. Analog output functions are handled by the Woodward 9905-867 analog output module, which drives actuators, control valves, and variable-speed drives based on the setpoints calculated by the CPU using the analog input data acquired by the 9905-968.

Digital I/O functions — including start/stop commands, alarm acknowledgements, and protective relay trip signals — are managed by the Woodward 9905-838 digital output module and its companion digital input module, both of which share the same backplane bus and participate in the same deterministic scan cycle. Communication with plant-level DCS and SCADA systems is routed through the Woodward 9905-977 communication gateway, which translates the internal backplane data into MODBUS TCP or MODBUS RTU frames for transmission over the plant Ethernet or RS-485 network. The Woodward 9905-791 terminal board provides the field wiring interface for the 9905-968, offering clearly labeled screw terminals for each analog input channel and simplifying loop wiring during installation and maintenance. For larger installations requiring additional I/O capacity, the Woodward 9905-458 I/O expansion chassis extends the rack capacity without requiring changes to the control application software. HMI functions are typically provided by a Woodward-compatible operator panel or a third-party industrial touchscreen connected via the communication gateway, giving operators real-time visibility into the analog process values acquired by the 9905-968.

The Woodward 9905-968 is deployed across a broad range of industrial control applications where precise analog signal acquisition is essential to safe and efficient operation. In gas turbine power generation, the module acquires exhaust temperature, compressor inlet pressure, fuel flow, and vibration signals, providing the 9905 governor with the real-time process data required for fuel scheduling, load control, and protective shutdown logic. In steam turbine governing applications at thermal power plants and industrial cogeneration facilities, the 9905-968 monitors steam pressure, temperature, and flow signals, enabling the governor to maintain precise speed and load control across varying steam conditions.

In oil and gas compression applications, the module acquires suction and discharge pressure signals, interstage temperature measurements, and lube oil pressure readings from field-mounted transmitters, feeding the 9905 control system with the data required for anti-surge control, load sharing between parallel compressor trains, and condition-based maintenance scheduling. In water and wastewater treatment facilities, the 9905-968 monitors pump discharge pressure, flow rates, and chemical dosing signals, supporting automated process control and regulatory compliance reporting. In marine propulsion and auxiliary machinery applications, the module's extended temperature rating and vibration tolerance make it suitable for engine room installations on vessels operating in demanding sea conditions. Across mining, metallurgy, and heavy process industries, the 9905-968 provides the analog signal acquisition backbone for motor control centers, kiln drives, and large rotating machinery protection systems, where signal accuracy and system reliability directly impact production throughput and equipment longevity.

Q1: Is the Woodward 9905-968 compatible with both simplex and redundant 9905 control architectures?Yes. The 9905-968 is designed for use in both simplex and redundant Woodward 9905 configurations. In redundant architectures, the module's analog input data is simultaneously accessible to both the active and standby 9905 CPU modules via the shared backplane bus, enabling bumpless controller switchover without loss of process visibility. No additional hardware or software configuration is required to enable redundant operation — the redundancy behavior is managed by the 9905 CPU modules and the system configuration loaded through Woodward Toolkit.

Q2: What commissioning tools and procedures are required to configure the 9905-968 for a new installation?Configuration and commissioning of the 9905-968 are performed using the Woodward Toolkit software application, which provides a graphical interface for channel assignment, signal scaling, alarm threshold configuration, and loop calibration. The module is automatically recognized by the 9905 CPU upon insertion into the rack, and all configuration parameters are stored in the CPU's non-volatile memory. Site acceptance testing procedures, including loop accuracy verification and channel isolation checks, are supported within the Toolkit environment. NANKMOS can provide technical commissioning support and documentation upon request.

Q3: What warranty and supply assurance does NANKMOS provide for the Woodward 9905-968?Every Woodward 9905-968 supplied by NANKMOS is covered by a 12-Month Warranty from the date of delivery, covering manufacturing defects and functional performance. Prior to shipment, each module undergoes pre-dispatch functional verification including channel accuracy testing, isolation resistance measurement, and backplane communication validation. NANKMOS maintains stock of the 9905-968 to support urgent replacement requirements, with fast global shipping available to minimize downtime for facilities experiencing module failures. For volume procurement, long-term supply agreements, and technical support, contact NANKMOS at [email protected] or +86 18359268345.