Yokogawa UT35A / UT32A Digital Indicating Controller

A universal-input PID controller with a colour display and a ladder sequence

The Yokogawa UT35A (96 x 96 mm) and UT32A (48 x 96 mm) are single-loop digital indicating controllers from the UTAdvanced series. Each has a 14-segment colour LCD with a PV display that can change colour on alarm, a guide display that shows parameter names, navigation keys, a 200 ms control period and a built-in ladder sequence function (up to 300 steps) that handles simple interlocks without an external PLC. The case is only 65 mm deep behind the panel, and the front is rated IP66 (NEMA 4, hose-down test only).

Typical duty is temperature, pressure or flow control on furnaces, ovens, dryers, heat-treatment lines, boilers and skid-mounted packages. Control types are PID, ON/OFF, two-position two-level and heating/cooling control, with Super and Super 2 functions that suppress overshoot and hunting, four target setpoints with four PID sets, and auto-tuning in Normal or Stable mode.

Technical specifications

Inputs, outputs and communication

The single universal input accepts thermocouples (K, J, T, B, S, R, N, E, L, U, W, Platinel 2, PR20-40, W97Re3-W75Re25), RTDs (JPt100 and Pt100, 3-wire) and standard signals of 0.4 to 2 V, 1 to 5 V, 4 to 20 mA, 0 to 2 V, 0 to 10 V, -10 to 20 mV and 0 to 20 mA. Accuracy is plus or minus 0.1 percent of the instrument range plus 1 digit for most thermocouple types above 0 C and for RTD and standard signals. Outputs are a control relay or 4-20 mA/voltage pulse output, a retransmission output or 15 V DC loop supply, 2 contact inputs and 3 relay alarm outputs, with extra contact I/O by option code.

Communication options are RS-485 (Modbus RTU/ASCII, PC link, ladder, peer-to-peer), Ethernet (Modbus/TCP with serial gateway), CC-Link, PROFIBUS-DP and DeviceNet, the last three with Modbus master function. The UT32A supports only RS-485 and CC-Link.

Model code and options

The model code for UT35A is Type 1 (basic control: -0 standard, -1 position proportional, -2 heating/cooling), Type 2 (functions: 0 none, 1 two extra DIs and DOs, 2 five extra DIs and DOs), Type 3 (open network: 0 none, 1 RS-485, 2 Ethernet, 3 CC-Link, 4 PROFIBUS-DP, 5 DeviceNet), display language (-1 English, -2 German, -3 French, -4 Spanish), case colour (0 white, 1 black) and the fixed code -00. Option codes are /LP 24 V DC loop power supply, /HA heater break alarm, /DC 24 V AC/DC supply, /CT coating, /CV terminal cover, /MDL DIN-rail mounting and /RSP non-isolated remote input. The /CT coating option removes the UL, CSA and CE conformity, and several options have combination limits, so verify the full code against the datasheet.

Installation and what to confirm before ordering

Panel cutout is 92 x 92 mm for the UT35A and 45 x 92 mm for the UT32A, weight is 0.5 kg or less and wiring is by M3 screw terminals. Supply is 100 to 240 V AC (18 VA for UT35A) or 24 V AC/DC with /DC. Operating temperature is -10 to 50 C (-10 to 40 C side by side), and the instrument should be warmed up for 30 minutes. Confirm the sensor type and range, whether you need heating/cooling or position-proportional output, the relay or current output for your actuator, communication protocol, panel size and any approval; the datasheet lists CE, UL and CSA. The attached file is the 14-page Yokogawa general specification GS 05P01D31-01EN. Related controllers in controllers and data acquisition include the larger-case UTAdvanced models. Send the full code for a quotation.