FUJI TEC-1VM Modules | EP-3955B High Power Motherboard

Technical Dossier

Product Details And Specifications

FUJI TEC-1VM Series: Comprehensive Module Range and Technical Overview

The FUJI TEC-1VM series represents a core hardware platform deployed across heavy industrial environments globally, including petrochemical refineries, nuclear power facilities, chemical processing plants, and large-scale manufacturing automation systems. Engineered by Fuji Electric, the TEC-1VM architecture was designed to meet the stringent reliability and deterministic control requirements of continuous-process industries where unplanned downtime carries significant operational and safety consequences. Installed base records indicate widespread deployment across Asia-Pacific, the Middle East, and European industrial sectors, with many installations now operating beyond their original design lifecycle. The EP-3955B High Power Motherboard is a central backplane component within this series, providing the primary bus interconnect and power distribution infrastructure for multi-module rack configurations.

The Evolution of TEC-1VM Architecture

The TEC-1VM platform was introduced as part of Fuji Electric's mid-generation DCS and programmable controller expansion during the late 1990s and early 2000s. Early revisions of the architecture utilized parallel backplane bus communication with fixed-slot addressing, which imposed strict module positioning requirements within the rack. Subsequent hardware revisions introduced improved bus arbitration logic and enhanced EMI shielding to address interference issues observed in high-voltage industrial environments.

The EP-3955B High Power Motherboard specifically addresses power delivery requirements for racks populated with high-current I/O modules and communication adapters. Compatibility across TEC-1VM sub-revisions requires verification of firmware version alignment between the motherboard and installed CPU modules. Older EP-series motherboards are not forward-compatible with later-generation CPU cards without hardware modification. As the TEC-1VM series has entered its mature-to-end-of-life phase, Fuji Electric has transitioned support to successor platforms; however, the installed base remains extensive, making long-term spare parts availability a critical operational concern for maintenance engineers.

TEC-1VM Full Catalog & Functionalities (SKU List)

The following SKUs represent verified components within the FUJI TEC-1VM series, organized by functional category. Each module is a discrete field-replaceable unit (FRU) within the TEC-1VM rack architecture.

Motherboards & Backplanes

• EP-3955B: High power motherboard; primary backplane for multi-slot TEC-1VM rack configurations with enhanced power bus capacity.
• EP-3954A: Standard power motherboard; base backplane for standard I/O density rack builds.
• EP-3956C: Extended slot backplane; supports up to 16-module configurations for high-density I/O applications.

CPU & Controller Modules

• TEC-1VM-CPU01: Main processing unit; executes ladder logic and function block programs with deterministic scan cycle control.
• TEC-1VM-CPU02: Redundant CPU module; hot-standby configuration for fault-tolerant control applications.
• TEC-1VM-CPU03: High-speed CPU variant; reduced scan cycle time for fast-response process control loops.

Digital Input (DI) Modules

• TEC-1VM-DI16A: 16-channel 24VDC digital input module; sink/source configurable, with per-channel LED status indication.
• TEC-1VM-DI32B: 32-channel high-density digital input module; compact form factor for space-constrained panel installations.
• TEC-1VM-DI16C: 16-channel 120VAC digital input module; for direct interface with AC field devices without external signal conditioning.

Digital Output (DO) Modules

• TEC-1VM-DO16A: 16-channel transistor output module; 24VDC, 0.5A per channel, short-circuit protected.
• TEC-1VM-DO16B: 16-channel relay output module; dry contact, rated 2A per channel for motor starter and solenoid valve control.
• TEC-1VM-DO32A: 32-channel high-density transistor output; for large-scale discrete output applications.

Analog Input (AI) Modules

• TEC-1VM-AI08A: 8-channel analog input module; 4–20mA / 0–10V selectable, 12-bit resolution, for process variable acquisition.
• TEC-1VM-AI08B: 8-channel thermocouple input module; supports J, K, T, E type thermocouples with cold junction compensation.

Analog Output (AO) Modules

• TEC-1VM-AO04A: 4-channel analog output module; 4–20mA, 12-bit resolution, for control valve and variable speed drive setpoint transmission.

Communication Adapters

• TEC-1VM-COM01: RS-232C/RS-485 serial communication adapter; for SCADA host and HMI connectivity via Modbus RTU protocol.
• TEC-1VM-COM02: Ethernet communication module; 10/100 Mbps, supports Modbus TCP and proprietary Fuji protocol for DCS integration.
• TEC-1VM-COM03: PROFIBUS-DP slave adapter; for integration into Siemens and third-party PROFIBUS master networks.

Power Supply Modules

• TEC-1VM-PSU01: 24VDC rack power supply; 10A output, wide-range AC input (85–264VAC), with power-fail relay output.
• TEC-1VM-PSU02: Redundant power supply module; for N+1 power redundancy configurations in critical process applications.

Sourcing Hard-to-Find & Obsolete TEC-1VM Parts

The TEC-1VM series has been formally discontinued by Fuji Electric, with OEM spare parts availability progressively declining. DriveKNMS maintains a dedicated inventory program for end-of-life Fuji Electric control system components, including the EP-3955B and associated TEC-1VM modules. Sourcing channels include decommissioned plant equipment, authorized distributor surplus stock, and tested pull inventory from controlled industrial environments.

All obsolete TEC-1VM components supplied by DriveKNMS are subject to full functional verification prior to dispatch. Customers operating legacy TEC-1VM installations are advised to conduct a spare parts audit and establish a buffer stock strategy for critical single-point-of-failure modules, particularly CPU units, power supplies, and the EP-3955B backplane, which are not field-repairable and carry long lead times when sourced through standard channels. DriveKNMS provides lifecycle extension consultation to assist maintenance teams in prioritizing procurement based on module failure rate data and remaining operational life projections.

Quality Control for the TEC-1VM Range

The TEC-1VM series employs a proprietary parallel backplane bus architecture with tight electrical timing tolerances. Standard bench testing procedures are insufficient to validate module integrity for this platform. DriveKNMS applies a dedicated test protocol for TEC-1VM components that includes the following stages:

• Backplane Bus Integrity Test: The EP-3955B and other backplane modules are tested under simulated full-rack load conditions to verify bus signal integrity, power rail stability, and slot-to-slot communication timing compliance.
• CPU Functional Verification: CPU modules are loaded with a standardized test program and executed through a full scan cycle sequence to confirm program execution, memory integrity, and communication port functionality.
• I/O Channel-Level Testing: Each channel of DI, DO, AI, and AO modules is individually stimulated and measured against factory specification tolerances. Analog modules are calibrated using traceable reference instruments.
• Communication Protocol Validation: Communication adapter modules are tested for protocol compliance using protocol analyzers configured for Modbus RTU, Modbus TCP, and PROFIBUS-DP as applicable.
• Thermal Burn-In: Selected modules undergo a 48-hour powered burn-in at elevated ambient temperature to screen for latent component failures prior to shipment.
• Visual and Physical Inspection: All modules are inspected for connector pin condition, PCB contamination, capacitor condition, and evidence of prior repair or counterfeit indicators.