The Yokogawa UT351 is a 1/4 DIN digital indicating controller designed for precise process and temperature control. Featuring multi-input support (TC, RTD, mV, V) and RS485 communication capability, it is widely used in industrial automation, furnace monitoring, and process control systems.

Key Features

Universal Inputs: Accepts Thermocouple (TC), Resistance Temperature Detector (RTD), mV, and V inputs.
RS485 Communication Interface: Serial communication support via terminals for remote monitoring and BAS/SCADA integration.
Loop Power Supply (LPS): Built-in 24 VDC transmitter power supply.
Multiple Output Options: Relay outputs for control and alarms, alongside 4–20mA analog / pulse control outputs.
Global Certifications: CSA, UL Recognized, CE Marked, and C-Tick (N200) compliant.

Technical Specifications

Specification	Details
Manufacturer	Yokogawa
Model	UT351
Suffix Code	-00
Style	S3
Part / Serial Number	T1G417670 716
Power Supply	100–240 VAC, 50/60 Hz
Power Consumption	20 VA max.
Ambient Temperature	50 °C max.
Country of Origin	Made in Korea

Terminal Wiring Configuration

Terminals 1–3 (Relay Output 1): 1 (NC), 2 (NO), 3 (COM)
Terminals 4–7 (Alarm / Relay Outputs): ALM3 / Output 2, ALM2, ALM1, COM
Terminals 8–10 (Power Supply): 8 (L - Line), 9 (N - Neutral), 10 (Ground/Earth)
Terminals 11–13 (Analog Inputs): mV/V/TC input (+) / (-), RTD (A, b, B)
Terminals 14–17 (Analog Outputs): 4–20mA / Pulse outputs for Output 1 and Output 2
Terminals 18–20 (Digital Inputs): DI1, DI2, COM
Terminals 21–22 (LPS): 24 VDC transmitter power (+ / -)
Terminals 23–27 (RS485): SDB(+), SDA(-), RDB(+), RDA(-), SG (Signal Ground)
Terminals 28–30 (CT Input): Current Transformer inputs (CT1, CT2, COM)