Yokogawa UT75A Advanced Digital Indicating Controller

A top-of-range UTAdvanced controller with dual-loop control and a program pattern

The Yokogawa UT75A is the high-end 96 x 96 mm model of the UTAdvanced series. It combines the standard UTAdvanced colour LCD, ladder sequence and open networks with features the smaller UT models lack: dual-loop control (control mode 11, with type 1 code -5), a program pattern function that ramps and soaks the setpoint over time, and an optional carbon potential calculation for furnace atmosphere control. That makes it a natural controller for heat-treatment furnaces, kilns, autoclaves, test chambers and batch reactors where one instrument has to run a temperature profile and, on the dual-loop type, two independent loops.

Available control modes are single loop, cascade primary and secondary, cascade, backup, PV switching, PV auto-selector (maximum, minimum, average, difference), PV hold and dual loop. Control types include PID, ON/OFF, heating/cooling, sample PI, batch PID and feed-forward, with the control period selectable at 50, 100 or 200 ms (50 ms cannot be combined with cascade or dual-loop control or the Super functions).

Technical specifications

Program pattern, setpoints and alarms

The program pattern function raises or lowers the target setpoint according to a pattern made of line segments. The datasheet gives one program pattern with up to 20 segments, a segment time of 0.00 to 99.59 (hours and minutes, or minutes and seconds), 0 to 999 repeat cycles or continuous repetition, and wait zones on the upper and lower side of the program setpoint so the timer pauses while the process catches up. The controller holds twenty sets of target setpoints and alarm setpoints and sixteen sets of PID parameters (sixteen each for loop 1 and loop 2 in cascade and dual-loop control), with PID selection by setpoint number, measured-value zone, target-setpoint zone or reached-setpoint zone. Alarm types cover PV, deviation, rate-of-change, setpoint, output and self-diagnosis alarms, up to eight alarm settings per loop with stand-by, latch, hysteresis and delay timer functions.

Model code, I/O and options

The type 1 code selects basic control: -0 standard, -1 position proportional or -5 dual loop. Type 2 selects the I/O set: 0 adds five DIs and five DOs; 1 adds a remote auxiliary analog input, RS-485 (19.2 kbps, 2-wire), one DI and five DOs; 2 adds two remote analog inputs, RS-485 and two DIs; 3 adds a remote analog input, six DIs and five DOs (not with -5). Type 3 selects the network: 0 none, 1 RS-485 (38.4 kbps) with five extra DIs, 2 Ethernet with serial gateway, 3 CC-Link, 4 PROFIBUS-DP, 5 DeviceNet. The analog input count ranges from one to four and analog outputs from two to three depending on the code. Display language -1 English and -4 Spanish are standard, with German and French as customised orders; case colour is 0 white or 1 black. Options are /DC 24 V AC/DC supply, /CP carbon potential calculation (only with type 2 codes 1, 2 or 3) and /CT coating, which removes UL, CSA and CE conformity.

Installation and what to confirm before ordering

The unit is 96 x 96 mm, 65 mm deep behind the panel, weighs 0.5 kg or less, has an IP66 front (NEMA 4, hose-down test only) and uses M3 screw terminals. A terminal cover, mounting brackets, unit label and the operation guide for single-loop control are supplied as standard. Confirm the control mode and whether dual loop is needed, the profile (segments, repeats, wait zones), sensor type, output devices, remote inputs, network and whether carbon potential is required for the atmosphere. The attached file is the 13-page Yokogawa general specification GS 05P01B41-01EN. See also the UT35A and UT55A in controllers and data acquisition. Send the full model and suffix code for a quotation.