Yokogawa UT35A Digital Indicating Temperature Controller

Product Description

The Yokogawa UT35A is a high-performance digital indicating controller from the UTAdvanced series, designed for demanding industrial process control applications that require both precision and flexibility. Built in a 1/4 DIN panel-mount format, it integrates advanced temperature control, logic sequencing, and open network communication within a compact enclosure.

A large color LCD provides clear visualization of process values, setpoints, alarm states, and trend information. The controller supports multiple control strategies beyond basic PID, enabling it to manage complex thermal and process loops without the need for additional control hardware.

Design and Operation

The UT35A emphasizes usability in industrial environments. Front-panel navigation keys allow engineers to configure parameters, tune control loops, and monitor system status efficiently. The short mounting depth simplifies panel layout and reduces installation constraints in crowded control cabinets.

Its built-in ladder sequence function enables execution of basic logic and interlock operations, allowing the controller to replace small PLCs in applications where compact control architectures are preferred.

Control and Processing Capabilities

The Yokogawa UT35A supports a wide range of advanced control modes to handle complex process dynamics:

Single-loop PID and ON/OFF control
Heating and cooling control with independent outputs
Cascade control with primary and secondary loops
Batch PID control for time-based processes
Feedforward control to compensate for external disturbances

Fast internal processing enables a control cycle as short as 250 ms, contributing to stable response and high loop performance even under rapidly changing process conditions.

Technical Specifications

Model: UT35A
Series: Yokogawa UTAdvanced

Mechanical and Display

Panel size: 1/4 DIN (96 × 96 mm)
Display type: Large color LCD, 14-segment
Indication: Dual 5-digit high-resolution PV and SP display
Front panel protection: IP65

Input Configuration

Universal input selectable by parameter
Thermocouples: K, J, T, E, N, R, S, B, L, U, PL-II
RTDs: Pt100, JPt100
Analog signals: DC voltage and DC current inputs

Output Options

Relay contact output
Voltage pulse output (for SSR drive)
Analog current output: 4–20 mA DC
Expandable digital outputs for alarm or logic use

Performance

Control accuracy: ±0.1% of span (typical)
Control period: 250 ms
PID setpoints: Up to four selectable profiles

Alarm and Logic

Three standard alarm outputs
Expandable up to eight digital outputs
Ladder sequence programming included as standard
Instruction set: 13 basic commands, 73 application-level commands

Communication Interfaces

Ethernet (open network compatible)
RS-485 with Modbus protocol support
Suitable for PLC, HMI, and SCADA integration

Power Supply

100–240 V AC
24 V AC/DC (model dependent)

Application Areas

The UT35A is suitable for industrial processes requiring advanced temperature or process control combined with local logic execution:

Heat treatment furnaces and industrial ovens
Chemical and pharmaceutical processing systems
Food and beverage production equipment
Plastic extrusion and packaging machinery
Manufacturing lines with cascade or batch control requirements

Frequently Asked Questions

Can the UT35A replace a small PLC in simple applications?
Yes. The built-in ladder sequence function allows implementation of interlocks, timers, and basic logic, reducing the need for an external PLC in compact systems.

Does the UT35A support network-based monitoring?
Yes. Ethernet and RS-485 interfaces enable integration with PLCs, HMIs, and SCADA platforms using open communication protocols.

Is the controller limited to temperature control only?
No. While commonly used for temperature regulation, the universal input and advanced control modes allow it to handle various process variables.