YS150-012/A31 S3

The Yokogawa YS150-012/A31 S3 is identified as a multifunction controller in the YS150 product range. Its exact hardware configuration, control functions, input and output specifications, and suffix-specific options need to be distinguished from other YS150 variants before technical parameters or installation requirements can be stated.

Functional Overview

The YS150 is a microprocessor-based single-loop controller designed to process measurement signals and execute configured control strategies. It provides local process indication, controller parameter adjustment, and signal interfacing with external field devices.

The controller is intended for panel mounting. Its control configuration determines how analog inputs, contact inputs, analog outputs, and contact outputs are assigned within the control loop.

Communication Interface

The /A31 option provides an RS-485 serial communication interface. Supported communication protocols include:

• Modbus
• PC-Link
• YS protocol

The interface supports data exchange between the controller and external communication equipment. Communication wiring, protocol selection, and termination settings must be configured according to the connected system.

Technical Specifications

Parameter	Specification
Model	YS150-012/A31 S3
Brand	Yokogawa
Product Type	Single-Loop Multifunction Controller
Controller Series	YS150
Power Supply Code	-012
AC Power Input	138-264 VAC
AC Frequency	47-63 Hz
DC Power Input	120-340 VDC
Communication Interface	RS-485
Communication Option	/A31
Supported Protocols	Modbus, PC-Link, YS protocol
Mounting	Panel mounting

The power input ranges and option descriptions are documented in Yokogawa's YS100 Series Installation and Operation Manual.

Configuration and Signal Handling

The YS150 operates as a single-loop controller. Its control strategy determines the relationship between the process measurement, controller calculations, and output signals. The actual signal assignments depend on the configured controller functions and installed options.

When integrating the controller into an existing installation, verify the installed input configuration and rear-terminal wiring rather than assuming that all YS150 units have identical signal interfaces.

Frequently Asked Questions

Q: What is the function of the /A31 option?

A: /A31 identifies the RS-485 communication option. It supports Modbus, PC-Link, and YS protocol communication. It should not be confused with the separate DCS-LCS communication option /A32.

Q: What power supply does the YS150-012 use?

A: The -012 power code specifies an input range of 138-264 VAC at 47-63 Hz or 120-340 VDC. Check the equipment nameplate and installed power supply before connecting the instrument.

Q: Is the YS150 still manufactured by Yokogawa?

A: No. Yokogawa officially discontinued the YS150 on January 1, 2008. The YS1500 indicating controller is identified as its successor product family. Replacement selection requires checking the original hardware and option configuration.

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