SANRITZ SC2120 Modules: SC2120-3 Processor Board

Technical Dossier

Product Details And Specifications

SANRITZ SC2120 Series: Comprehensive Module Range and Technical Overview

The SANRITZ SC2120 series is a distributed control system (DCS) processor and I/O module platform developed by Sanritz Automation Co., Ltd. (Japan). This series has been deployed across heavy industrial sectors including petrochemical refineries, chemical processing plants, power generation facilities, and pulp & paper mills throughout Asia-Pacific and beyond. The SC2120 platform is characterized by its modular backplane architecture, deterministic scan-cycle execution, and compatibility with SANRITZ's proprietary field bus infrastructure. Its installed base in long-lifecycle industrial environments means demand for spare parts and replacement boards remains active well into the platform's mature phase.

The Evolution of SC2120 Architecture

The SC2120 series was introduced as part of SANRITZ's second-generation DCS platform, succeeding earlier relay-logic and analog control panels. The architecture centers on a passive backplane bus that allows hot-swap-capable module insertion in supported configurations. Early revisions of the SC2120 processor board (including the SC2120-1 and SC2120-2 suffixes) used mask-ROM firmware with fixed scan rates. The SC2120-3 revision introduced EEPROM-based firmware storage, enabling field firmware updates and expanded diagnostic registers accessible via the front-panel RS-232 port.

Compatibility across suffix revisions is partial: SC2120-3 boards are backward-compatible with SC2120-2 backplane slots in most chassis configurations, but firmware version alignment with the system supervisor module is required. Migration from SC2120-1 to SC2120-3 requires a backplane adapter bracket in certain chassis generations. As the SC2120 series has entered its end-of-production phase, SANRITZ no longer manufactures new units; lifecycle extension is now the primary procurement strategy for existing installations.

SC2120 Full Catalog & Functionalities (SKU List)

The following SKUs represent verified components within the SANRITZ SC2120 platform. Units are classified by functional role:

Processor / CPU Modules

• SC2120-1: First-revision CPU board; mask-ROM firmware; fixed 50ms scan cycle.
• SC2120-2: Second-revision CPU; expanded memory map; RS-232 diagnostic port added.
• SC2120-3: Current production CPU board; EEPROM firmware; dual-port communication support.
• SC2120-3A: Enhanced variant of SC2120-3 with extended temperature tolerance (-10°C to +60°C).

Digital Input (DI) Modules

• SC2121-1: 16-channel 24VDC DI module; sink/source configurable; LED status per channel.
• SC2121-2: 32-channel 24VDC DI module; high-density format; common return bus.
• SC2121-3: 16-channel 120VAC DI module; optical isolation; surge protection rated.

Digital Output (DO) Modules

• SC2122-1: 16-channel 24VDC DO module; transistor output; 0.5A per channel.
• SC2122-2: 16-channel relay output module; Form-C contacts; 2A/channel at 250VAC.
• SC2122-3: 32-channel 24VDC DO module; high-density; short-circuit protection per channel.

Analog Input (AI) Modules

• SC2123-1: 8-channel 4–20mA AI module; 12-bit resolution; individual channel isolation.
• SC2123-2: 8-channel ±10VDC AI module; 14-bit resolution; differential input configuration.
• SC2123-3: 4-channel thermocouple input module; K/J/T/E type selectable; cold-junction compensation.

Analog Output (AO) Modules

• SC2124-1: 4-channel 4–20mA AO module; 12-bit resolution; loop-powered output option.
• SC2124-2: 4-channel ±10VDC AO module; 14-bit resolution; simultaneous update mode.

Communication & Network Adapters

• SC2125-1: RS-485 communication adapter; Modbus RTU master/slave; up to 32 nodes.
• SC2125-2: Ethernet adapter module; 10/100BASE-T; Modbus TCP support.

Power Supply Modules

• SC2126-1: 24VDC backplane power supply; 5A output; over-voltage and over-current protection.
• SC2126-2: Redundant power supply module; hot-swap capable; status relay output.

Sourcing Hard-to-Find & Obsolete SC2120 Parts

SANRITZ has formally discontinued new production of the SC2120 series. For facilities operating SANRITZ-based DCS installations, unplanned board failures present a critical operational risk when OEM channels are exhausted. DriveKNMS maintains a dedicated inventory of tested SC2120-series modules sourced through authorized decommissioning projects, factory overstock channels, and certified refurbishment pipelines.

DriveKNMS provides lifecycle extension support including: direct replacement of failed SC2120-3 processor boards with functionally equivalent tested units; cross-reference matching for suffix variants where direct replacements are unavailable; and documentation support for firmware version compatibility verification. All units are shipped with full traceability records. Emergency same-day quotation is available for critical plant shutdown scenarios.

Quality Control for the SC2120 Range

The SC2120 backplane bus operates at 5VDC logic levels with a proprietary parallel data bus. Standard bench testing protocols are insufficient for validating SC2120 processor boards without a compatible chassis and supervisor module. DriveKNMS employs dedicated SC2120-series test fixtures that replicate the backplane electrical environment, enabling full functional verification including: CPU boot sequence and firmware integrity check; scan cycle timing verification against specification (±2ms tolerance); all I/O channel functional tests under simulated load; communication port loopback and protocol handshake validation; and thermal soak testing at 50°C for 4 hours prior to shipment approval.

Each unit is issued a test report documenting pass/fail results per test point, firmware version recorded, and technician sign-off. Units that fail any single test point are quarantined and not offered for sale.