Yokogawa YS1700-120/A31 Programmable Single-Loop Indicating Regulator

Product Description

Yokogawa YS1700-120/A31 is a programmable single-loop indicating controller of Yokogawa YS1000 series. YS1700-120 is YS100 compatible form factor, suffix /A31 indicates corresponding option code. It adopts dual-CPU architecture with battery-free non-volatile memory, built-in PID auto-tuning and supports user customized control program. Front panel meets IP54 rating for panel flush mounting. Integrated analog I/O and digital DI/DO channels. It can work as standalone loop controller or backup control station for DCS system. It supports Modbus and RS485 communication, compatible with Yokogawa CENTUM DCS, PLC and SCADA systems. Widely used for closed-loop regulation of boiler, pressure, level and flow. Some variants are discontinued by original manufacturer and supplied as spare parts for industrial automation maintenance.

Technical Parameters

• Model: YS1700-120/A31
• Brand: Yokogawa (Japan)
• Product Type: Programmable Single-loop Indicating Controller
• Series: YS1000 Series YS1700
• Form Factor: YS100 compatible type (120 version)
• Front Panel Protection: IP54
• CPU: Dual processor (main control + display CPU)
• Memory: Battery-free non-volatile memory
• Analog Input: 5 AI channels
• Analog Output: 2 AO (control output), 1 AO (indicator output)
• Digital I/O: 6 DI/DO points
• Control Algorithm: PID with auto-tuning, user-defined sequence & calculation program
• Communication: RS485, Modbus RTU, CENTUM DCS communication supported
• Power Supply: 100~240V AC or 24VDC optional
• Input Signals: 4-20mA, mV, thermocouple, RTD and other signals
• Accuracy: Current output ±0.2%; Voltage input ±0.1%
• Mounting: Panel flush mounting
• Functions: Loop trend display, alarm, hard manual backup station, PF programmable function keys
• Product Status: Some versions discontinued, spare part for process control

Product Application

It acts as standalone single-loop controller for closed-loop regulation of industrial boilers, pressure, liquid level, temperature and flow. It serves as backup control unit for DCS to keep process stable during DCS failure. Widely applied in petrochemical, power plant, water treatment, paper making, metallurgy and other process industries. It performs continuous process regulation, safety alarm and local manual operation. It is commonly used instrument for legacy control system retrofit and spare replacement.

Series Models

YS1700, YS1500, YS1360, YS1350