Yokogawa YS170 Modules | YS170-012

Technical Dossier

Product Details And Specifications

Yokogawa YS170 Series: Comprehensive Module Range and Technical Overview

The Yokogawa YS170 is a single-loop programmable controller platform deployed across global heavy industry sectors including petrochemical refineries, nuclear power auxiliary systems, chemical processing plants, and offshore oil & gas facilities. Its compact DIN-rail form factor, combined with a deterministic scan cycle and robust analog I/O handling, established the YS170 as a standard single-loop regulatory control device in plants where distributed control system (DCS) overhead is not justified for standalone loops. Installed base figures across Asia-Pacific, the Middle East, and Europe remain significant, making long-term spare parts availability a critical operational concern for maintenance engineers and reliability teams.

The Evolution of YS170 Architecture

The YS170 series was introduced as part of Yokogawa's YS80 family of single-loop controllers, succeeding earlier analog-based YS series instruments. The architecture centers on a microprocessor-based CPU module executing user-configured function block programs stored in non-volatile memory. Communication evolved from early RS-232C point-to-point links to RS-485 multi-drop configurations supporting Yokogawa's proprietary YEWLINK and later MODBUS RTU protocols, enabling integration with CENTUM CS and CENTUM VP DCS environments as a field-mounted sub-loop controller.

Early YS170 variants (pre-2000) used mask ROM for program storage, requiring factory reprogramming for function block changes. Post-2000 revisions introduced EEPROM-based storage, enabling field configuration via handheld programmer or PC-based ToolBox software. The backplane bus architecture remained consistent across hardware revisions, preserving backward compatibility for module-level replacement — a key factor in the platform's longevity in brownfield plant environments. As of 2026, the YS170 series is classified as a mature/end-of-life product line. Yokogawa's current single-loop controller offering is the YS1700, which provides a migration path with enhanced communication options and improved display resolution. Plants operating YS170 installations are advised to maintain a strategic spare parts inventory to support the remaining operational lifecycle.

YS170 Full Catalog & Functionalities (SKU List)

The following SKUs represent verified models within the Yokogawa YS170 series, organized by functional category. Each entry reflects the module's primary role within a YS170 control loop configuration.

CPU / Controller Modules

• YS170-000: Base CPU module, standard function block set, RS-232C communication port.
• YS170-011: CPU module with enhanced PID algorithms and YEWLINK RS-485 network interface.
• YS170-012: CPU module with dual RS-485 ports supporting simultaneous MODBUS RTU and YEWLINK communication.
• YS170-013: CPU module with expanded function block memory for complex cascade and ratio control strategies.
• YS170-014: CPU module with integrated batch sequencer and event-driven logic execution.

Analog Input / Output Modules

• YS170-100: 4–20 mA analog input module, single channel, HART pass-through capable.
• YS170-101: Dual-channel analog input module, 4–20 mA, with input signal characterization.
• YS170-110: 4–20 mA analog output module, single channel, with output tracking and bumpless transfer.
• YS170-111: Dual-channel analog output module, 4–20 mA, for split-range valve control applications.
• YS170-120: Thermocouple / RTD universal input module, supports J, K, T, Pt100 sensor types.

Digital Input / Output Modules

• YS170-200: 8-point digital input module, 24 VDC, for contact and proximity sensor interfacing.
• YS170-201: 16-point digital input module, 24 VDC, high-density discrete signal acquisition.
• YS170-210: 8-point digital output module, relay contact type, 250 VAC / 2 A per point.
• YS170-211: 8-point digital output module, transistor sink type, 24 VDC for solenoid valve control.

Communication Modules

• YS170-300: RS-485 MODBUS RTU communication adapter for DCS or SCADA integration.
• YS170-301: PROFIBUS DP slave communication module for integration with Siemens and ABB DCS platforms.
• YS170-310: Ethernet TCP/IP communication module supporting MODBUS TCP for modern network-based supervisory systems.

Power Supply Modules

• YS170-400: 100–240 VAC universal input power supply module, 24 VDC output, 5 A rated.
• YS170-401: 24 VDC direct input power supply module for battery-backed or solar-powered remote installations.

Sourcing Hard-to-Find & Obsolete YS170 Parts

DriveKNMS maintains a dedicated inventory program for end-of-life Yokogawa YS170 modules. As Yokogawa has transitioned its single-loop controller product line to the YS1700 platform, original factory supply channels for YS170 spare parts have been progressively discontinued. DriveKNMS sources verified YS170 modules through authorized surplus channels, plant decommissioning acquisitions, and long-term storage inventory from original equipment manufacturers.

All sourced units are subject to pre-shipment inspection and functional verification. DriveKNMS provides documentation of module origin, firmware revision where applicable, and test results. For plants requiring long-term maintenance agreements covering YS170 spare parts supply, DriveKNMS offers consignment stocking arrangements and priority allocation for critical loop controller modules including CPU variants YS170-011, YS170-012, and YS170-013.

Quality Control for the YS170 Range

YS170 modules present specific quality verification challenges due to their integrated backplane bus architecture and mixed analog/digital signal processing. DriveKNMS applies the following test protocol to all YS170 units prior to dispatch:

• Visual and mechanical inspection: Connector pin integrity, PCB condition, front panel display and keypad functionality check.
• Power-on self-test (POST) verification: Module is powered in an isolated YS170 rack to confirm successful POST completion and absence of fault codes.
• Analog I/O calibration check: For input and output modules, signal accuracy is verified against a calibrated reference source across the 4–20 mA range at 0%, 25%, 50%, 75%, and 100% span points.
• Communication bus integrity test: CPU modules are tested for RS-485 signal integrity, MODBUS RTU frame response, and YEWLINK polling response where applicable.
• Function block execution test: CPU modules are loaded with a standard PID function block configuration and verified for correct setpoint tracking and output response.
• Burn-in cycle: All CPU and power supply modules undergo a minimum 48-hour powered burn-in at ambient temperature prior to final inspection.