Foxboro I/A Series Modules: P0916SG-0B Contact Sense Module —

Technical Dossier

Product Details And Specifications

Foxboro I/A Series: Comprehensive Module Range and Technical Overview

The Foxboro I/A Series (Intelligent Automation Series) is one of the most widely deployed Distributed Control System (DCS) platforms in global heavy industry. Installed across petrochemical complexes, nuclear power stations, oil refineries, pulp and paper mills, and pharmaceutical manufacturing facilities, the I/A Series has maintained a dominant installed base since its commercial introduction in the mid-1980s. Its modular, redundant architecture — built around a fieldbus-based backplane and a deterministic real-time operating environment — made it the reference standard for continuous process control in safety-critical applications. Facilities operating Foxboro I/A Series systems represent decades of capital investment in engineering, commissioning, and operator training, making long-term spare parts availability a strategic operational requirement rather than a routine procurement task.

The Evolution of I/A Series Architecture

The I/A Series was introduced by Foxboro (now a brand under Schneider Electric's Foxboro/Triconex portfolio) in 1987 as a successor to the SPEC 200 and FOX 1/A platforms. The architecture is organized around the Nodebus and Fieldbus communication layers, with Control Processors (CPs) acting as the primary execution engines and I/O modules residing in FBM (Fieldbus Module) enclosures distributed across the plant floor.

Early generations (late 1980s–1990s) used parallel backplane designs with discrete analog and digital I/O modules. The mid-generation transition (late 1990s–2000s) introduced enhanced CP models (CP30, CP40, CP60) with expanded memory and faster scan rates. The modern generation (2000s–present) added Ethernet-based communication options and integration with AIM (Application Interface Module) platforms for historian and MES connectivity. Compatibility between generations is maintained at the Nodebus protocol level, but physical module form factors and firmware revisions must be matched precisely when sourcing replacement parts. Mixing incompatible firmware revisions on redundant module pairs is a documented failure mode that must be avoided during maintenance sourcing.

I/A Series Full Catalog & Functionalities — SKU List

Contact Sense / Digital Input Modules

• P0916SG-0B: 16-channel contact sense input module, 24 VDC, dry contact, FBM standard enclosure
• P0916SA: 16-channel contact sense input, 120 VAC wet contact, isolated channels
• P0916SB: 16-channel contact sense input, 48 VDC, field-powered configuration
• P0916SC: 16-channel contact sense input, 24 VDC, with diagnostics output

Analog Input Modules

• P0914TW: 8-channel analog input, 4–20 mA, HART-enabled, FBM enclosure
• P0914TX: 8-channel analog input, thermocouple/RTD universal input
• P0914YA: 16-channel analog input, 1–5 VDC, high-density configuration
• P0914YB: 8-channel analog input, millivolt/thermocouple, cold junction compensated

Analog Output Modules

• P0917TW: 8-channel analog output, 4–20 mA, HART pass-through
• P0917TX: 4-channel analog output, 4–20 mA, high-drive, valve positioner rated

Digital Output Modules

• P0918SA: 16-channel discrete output, 24 VDC sourcing, 0.5 A per channel
• P0918SB: 8-channel discrete output, 120 VAC, relay-isolated, 2 A per channel
• P0918SC: 16-channel discrete output, 48 VDC, sinking configuration

Control Processors (CPU Modules)

• P0914XS: CP30 Control Processor, 32 MB RAM, dual Nodebus ports, redundancy-capable
• P0914XT: CP40 Control Processor, 64 MB RAM, enhanced floating-point, Ethernet option
• P0914XU: CP60 Control Processor, 128 MB RAM, high-speed execution, AIM-compatible

Communication & Power Modules

• P0922VW: Nodebus Interface Module, dual-redundant coax, termination integrated
• P0922VX: Fieldbus Isolator Module, galvanic isolation, surge protection rated
• P0922YA: Power Supply Module, 24 VDC output, 10 A, redundant pair capable

Sourcing Hard-to-Find & Obsolete I/A Series Parts

Foxboro formally transitioned the I/A Series into a managed lifecycle phase following Schneider Electric's acquisition of the Foxboro brand. Many FBM-series I/O modules, early-generation CP processors, and associated backplane assemblies are no longer manufactured. Lead times from OEM channels for remaining new-old-stock units can exceed 26 weeks, and in many cases, the OEM no longer accepts orders for specific part numbers.

DriveKNMS maintains a dedicated inventory of I/A Series modules sourced through certified secondary market channels. All units are inspected, tested, and documented prior to shipment. For facilities operating under extended maintenance contracts or regulatory compliance frameworks (e.g., nuclear QA programs), DriveKNMS can provide traceability documentation and test records on request. Customers with large BOM requirements are encouraged to submit full parts lists for consolidated quotation to minimize per-unit sourcing costs and consolidate shipping logistics.

Quality Control for the I/A Series Range

I/A Series modules present specific testing challenges due to their backplane-dependent communication architecture. Functional verification of FBM I/O modules requires active Nodebus or Fieldbus communication — bench-level continuity testing alone is insufficient to confirm module operability. DriveKNMS employs a structured test protocol for I/A Series units that includes: backplane insertion and bus enumeration verification, channel-level signal injection and readback for analog modules, contact closure simulation for discrete input modules (including the P0916SG-0B and related contact sense variants), output load testing for discrete and analog output modules, and firmware revision identification and documentation. Modules that fail any stage of this protocol are quarantined and not offered for sale. Test records are retained and available upon request for quality-sensitive procurement programs.