Autonics Temperature Controllers - A Comprehensive Guide

Temperature controllers are the foundation of precise industrial automation, directly influencing production quality, energy efficiency and profitability of manufacturing processes. Choosing the right solution requires understanding not only the technical specifications, but also the real business benefits and possibilities of integration with existing infrastructure.

What is a temperature controller and why is it crucial for your production

A temperature controller is an advanced automation device that receives electrical signals from a temperature sensor and sends control signals to the manipulator through a built-in algorithm, comparing the actual value (PV) with the set value (SV). In practice, this means that the device constantly monitors the process temperature and automatically adjusts the heating or cooling power, eliminating human error and ensuring repeatable production.

The temperature sensor converts the temperature into an electrical signal and is installed in the place where the temperature requires monitoring, while the manipulator (heater or cooler) heats or cools the object in accordance with the control signal transmitted from the controller. These three elements create a closed regulation system, which in Polish production plants is responsible for precise control of processes from plastic extrusion to fermentation in the food industry.

Temperature control types – which one to choose for your process

ON/OFF control – simplicity for less demanding applications

ON/OFF control turns the output on when the actual value is lower than the set value and turns it off when it is higher. This is the simplest control mode, suitable for applications where temperature fluctuations of ±2-3°C are allowed, such as heating warehouse rooms or maintaining the temperature in buffer tanks. However, due to overshoot and oscillations (hunting), it is not suitable for processes requiring high precision.

PID control – the gold standard of industrial automation

PID control combines three control modes (proportional, integral and derivative) providing optimal control response for time-delayed objects. PID controllers are widely used in the chemical, pharmaceutical and food industries, as well as in building automation and HVAC systems.

Proportional action (P) adjusts the output power proportionally to the deviation from the setpoint within a specified temperature range (proportional band), minimizing ON/OFF oscillations. Integral action (I) automatically corrects the offset of the proportional control, stabilizing the temperature at the set value, but requires a longer time for stabilization in the event of external disturbances. The differentiation effect (D) is proportional to the rate of temperature change, allowing rapid changes caused by disturbances to quickly stabilize.

Thanks to this combination, PID control eliminates the overshoot typical of proportional control (P), automatically corrects the offset of integral control (I), and quickly responds to external disturbances thanks to derivative control (D), resulting in optimal temperature control. Temperature controllers with PID play an important role in industrial automation, influencing the efficiency of production processes and resulting in better product quality and energy savings.

Auto-tuning – automatic optimization of parameters

The auto-tuning function measures the thermal characteristics and thermal response rate of the control object and then automatically determines the necessary PID constants. Values ​​can be adjusted manually after auto-tuning is completed, allowing for further optimization for a specific process. During auto-tuning, parameters other than auto-tuning cannot be changed, but they can be checked. The functions of automatic tuning of PID parameters significantly facilitate the implementation and shorten the time of launching new production lines.

Types of control outputs - selection according to the specific application

Relay output – reliability for power

The relay output controls the ON/OFF operation of the devices via a built-in relay contact. It is recommended to extend the distance 'A' between the controller and the load as much as possible when wiring, as the back-electromotive force from the magnetic contactor coil may affect the device's power line, causing interference. If the 'A' cable length is short, connect 104 (630 V) paint capacitors at both ends of the magnetic coil (MC) to protect against electromotive force.

SSR output – long life and precision

The SSR (solid state relay) control output emits a constant voltage as an output to control solid-state relays. The use of solid-state relays allows you to keep the configuration small and achieve half a century cycle life. When selecting cyclic or phase control mode, the power supply to the load and temperature controller must be the same. The SSR should be selected according to the load power, otherwise it may result in short circuit and fire, and for effective operation, it is recommended to use indirect heating heaters with the SSR.

Current output – stability for proportional drives

The current output (analog) is used to control an external power controller (SCR UNIT), control valve, etc. The output is stable and does not have sudden changes, which allows processed stable control. This solution works particularly well in applications requiring smooth power regulation, such as controlling proportional valves in cooling processes or precise control of heater power in extrusion systems.

Transmission output – monitoring and integration with superior systems

The transmission output is not used for control, but for transmitting the actual value (PV) externally. Typically, PV is transmitted as a current, and in the case of DC 4-20mA transmission output, the device outputs a DC 4-20mA signal within the set high/low limit range. The 4mA output corresponds to the lower limit of the range, 12mA to the middle and 20mA to the upper temperature limit. This functionality enables integration with SCADA, MES or ERP systems for comprehensive production monitoring.

Alarm functions – proactive process and product protection

Temperature deviation alarms

Autonics controllers offer advanced alarm modes that protect the process against going beyond acceptable parameters. Up deviation alarm turns on the alarm output when the deviation between PV and SV exceeds the set value upwards. Lower deviation alarm works similarly for downward deviations. Upper and lower deviation alarm activates the alarm when the temperature goes outside the tolerance window in any direction. The Reverse deviation alarm only activates when the temperature is within the specified range.

Absolute Value Alarms

High absolute value alarm turns on the output when PV exceeds the set absolute value. Lower absolute value alarm activates when PV falls below the set value. These modes are particularly useful for protecting the product from excessive heating or freezing, regardless of the current process setpoint.

System diagnostic alarms

The Sensor Interrupt Alarm activates when it detects a missing or damaged sensor during temperature control, allowing you to check the sensor connection with a buzzer or other devices that use the alarm output pin. The Heater Interrupt Alarm detects a missing connection or damage to the heater through a current transducer (CT), which converts the current flow into a constant ratio (CT ratio), and the controller checks whether the circuit is open. Loop Break Alarm (LBA) checks the control loop and sends an alarm based on the change in object temperature - for heating control, when the MV output is 100% and PV does not rise above the LBA detection band during LBA monitoring, or when the MV output is 0% and PV does not fall below the LBA detection band.

Alarm mode options

The controllers offer various alarm operation options tailored to the specific process. Standard alarm turns the output on when an alarm condition occurs and turns it off when normal returns. The Latch Alarm keeps the output on even after recovery, requiring manual confirmation. Standby sequence 1 ignores the first alarm condition after power-up, activating the alarm only from the second occurrence. Standby sequence 2 additionally ignores the alarm when the alarm value or option settings are changed.

Criteria for selecting a temperature controller – 9 steps to the optimal solution

Autonics defines nine key elements of temperature controller selection for optimal detection and control:

• Temperature control type – select the control mode appropriate to the purpose of use: indication only, ON/OFF, P/PI/PID control, etc.
• Operation type – define the operating mode: standard, cooling, etc.
• Housing shape – choose the product structure: standard, modular, plate, with knobs, etc.
• Mounting type – specify the installation method: panel, DIN rail, etc.
• Control output – select the output type: relay, SSR, current, etc.
• Control type – define the algorithm: ON/OFF, P/PI/PID, etc.
• Input specification – select the sensor type: thermocouple, RTD resistance sensor, analog, etc.
• Communication – select the communication type (connection, protocol): RS485, RS422, Ethernet and PLC ladderless protocols, Modbus RTU, ASCII, etc.
• Optional inputs/outputs – specify whether support for CT input, digital inputs, transmission output, alarm outputs, etc. is required.

Temperature sensors - the foundation of precise measurement

Thermocouples – universality for extreme conditions

A thermocouple is a sensor that uses the thermoelectric effect - after connecting and welding two different metals, a thermoelectromotive force is created when the temperature is applied to the junction. Thermocouples are commonly used in industrial applications such as steel mills, power plants and the heavy chemical industry. The accuracy of a thermocouple is no higher than that of a platinum RTD, and a thermocouple system may be more expensive due to the compensation wiring required.

Sheathed thermocouples consist of a jacket and insulated measurement leads with a magnesium oxide filling. They have a quick response to temperature changes, high mechanical, corrosion and pressure resistance. They are available in three designs: grounded (wires welded directly to the jacket, fastest response, suitable for measuring high temperature and pressure, but uninsulated has limitations in various applications), ungrounded (completely insulated between the conductors and the jacket, slower response but low influence of external factors, suitable for long-term use),exposed (exposed wires measurement, fastest response but low mechanical strength, unsuitable for corrosive, high-pressure or high-temperature environments).

Platinum RTD resistance sensors – precision for the regulated industry

The electrical resistance of the metal used in platinum resistance sensors has a constant relationship with temperature, so a platinum wire is used as a resistor. The platinum RTD is the most repeatable temperature sensor and has an almost linear positive temperature coefficient ranging from -260 to 630°C, which is why RTDs are used as the industry standard. The sensor is housed in an insulated protective tube and is widely used in dyeing, physical/chemical devices, processor control, but is slightly more expensive.

A 3-wire connection is required for the RTD sensor, and a compensating cable of the same length and diameter as the sensor cable is mandatory when using the RTD sensor because two different metal cables result in two different temperature values.

Thermistors – economics for less demanding applications

A thermistor is a semiconductor device with electrical resistance proportional to temperature, available in two types: PTC (positive temperature coefficient) and NTC (negative temperature coefficient). Most commonly used for machine assembly, inexpensive and small, but incompatible between manufacturers and non-linear, so the circuits cannot be used for industrial purposes or in circumstances where sensor compatibility is required. NTC is used for temperature detection/control, liquid/wind/vacuum level detection, inrush current prevention, delay element etc., and PTC is used for monitoring, demagnetization, constant temperature heating, overcurrent device etc.

Communication protocols – integration with industrial systems

Autonics temperature controllers support key industrial communication protocols, enabling integration with control and monitoring systems. RS485 and RS422are the most popular serial interfaces for industrial field communication. Ethernet enables integration with IT networks and superior systems. Modbus RTU is an open serial protocol widely used in automation. ASCII allows simple communication with terminals and computers. PLC ladderless enables direct communication with the PLC without ladder programming.

Advanced industrial protocols includeEtherNet/IP (an industrial protocol compliant with the Common Industrial Protocol on the standard Internet, one of the leading industrial protocols in the US, widely used in various industries),EtherCAT (an Ethernet-based fieldbus system developed by Beckhoff Automation, standardized in IEC 61158 since 2007, Ethernet-based communications requiring low jitter, short cycle time and reduced hardware costs), DeviceNet (digital multidrop network for connecting industrial controllers and I/O devices, uses CAN technology used in automotive vehicles), HART (global standard for digital information communication over analog cables between smart devices and control or monitoring systems), PROFINET (open standard for industrial Ethernet in automation technology, provides solutions for process, factory and control automation movement), PROFIBUS (open standard commonly used for process automation at the production site, up to 124 slaves and 3 masters can be connected to one communication line), CC-Link (open field network and global standard with SEMI certification, high-speed field network processing control and information data simultaneously at a communication speed of 10 Mbps).

Industry applications of temperature controllers

Food industry – product quality and safety

In the food industry, Autonics temperature controllers enable precise temperature control during processes such as baking or fermentation, which affects the quality of products and minimizes material losses. PID controllers are used in pasteurization lines, packaging processes, temperature control of cooling and freezing chambers and sous-vide systems. Precise temperature control is critical to meeting HACCP standards and ensuring food safety.

Chemical and pharmaceutical industry – repeatability of processes

In the chemical and pharmaceutical industries, the right temperature has a critical impact on the course of chemical reactions and the quality of final products. The use of precise RTD sensors and advanced PID controllers ensures repeatability of production processes and compliance with quality requirements. Documentation and alerting functions support meeting GMP requirements and process validation.

Plastics industry – extrusion and molding efficiency

Temperature controllers control the heating zones of extruders, injection molds and thermoforming lines. Precise PID control eliminates fluctuations in the temperature of the polymer mass, ensuring uniform product quality and minimizing production waste. Advanced auto-tuning functions reduce line retooling time when changing materials or products.

Building automation and HVAC - energy efficiency

In HVAC systems, modern temperature controllers with PID allow for more accurate process control, which translates into energy savings and reduction of CO2 emissions. In heating, advanced controllers enable optimal use of energy, which reduces CO2 emissions, and in air conditioning and ventilation, they ensure comfort with minimal energy consumption. The control systems achieve up to 90% lower energy consumption thanks to intelligent optimization functions.

Metallurgical industry – precision of heat treatment

Autonics temperature controllers are used in hardening, tempering, normalizing and carburizing. Temperature curve programming functions enable the implementation of complex heat treatment cycles, and alarm outputs protect against material microstructure defects. High-temperature thermocouples work with controllers in the range of up to 1800°C for melting and refining processes.

Economic benefits - ROI and TCO of implementing temperature controllers

Reduction of energy consumption

Modern temperature controllers with PID algorithms and optimization functions can reduce energy consumption by 27-42% compared to older solutions. Features such as "Energy-Control" allow you to reach the optimal operating point in just a few steps, resulting in up to 90% lower power consumption. Assuming 15 years of operation, energy savings can not only cover the cost of the device, but also generate additional profit by positively influencing the ROI indicator.

Minimization of production waste

Precise temperature control eliminates defective products caused by inappropriate process conditions. In the food industry, it minimizes material losses during baking or fermentation. In the pharmaceutical industry, it ensures compliance with quality requirements, eliminating the need for scrapping. Alarm functions proactively protect against process escaping acceptable parameters.

Increased operational efficiency

Auto-tuning functions eliminate the need for manual tuning of PID parameters by qualified specialists, shortening the time of launching new lines or retooling production. Simple, intuitive control and operation of devices together with comprehensive sensor monitoring minimize sources of errors and reduce defects. Remote diagnostics and industrial communication reduce downtime.

Reduction of maintenance costs

SSR outputs achieve half a century cycle life eliminating the cost of replacing relay contacts. Advanced system diagnostics (sensor interruption alarms, heater alarms, control loop alarms) allow for predictive maintenance before a failure occurs. Modular design and standardization of connections facilitate service and reduce spare parts inventories.

Compliance with standards and certification

Autonics controllers are CE, UKCA, UL, KC, TUV NORD and EtherNet/IP, EtherCAT, PROFINET, DeviceNet communication certified, ensuring compliance with European, American and international requirements. Reducing the risk of regulatory sanctions and production stoppages translates into operational stability and protection of the company's reputation.

Environmental protection standards - IP, working environment

Autonics controllers meet the IEC 60529 standards defining the degrees of protection against dust and water (IP Code). IP50 provides protection against dust with or without pressure - hermetic dustproof housings allow the entry of a limited amount of dust; complete protection against contact. IP54 combines protection against dust with protection against splashes of water from any direction without harmful effects on the product. IP65 offers complete dustproof protection and protection against pressurized water jets from any direction. IP66 is the highest protection against dust and powerful water jets from any direction.

The JEM 1030 (Japanese Electrical Manufacturers' Association) standard additionally defines the degrees of protection against oil: F marking (oil proof) - protection against oil drops and oil dust from all directions, even if oil penetrates the product, it functions normally; G marking (oil resistant) - protection against oil drops and oil dust from all directions, special coatings prevent oil from penetrating into the product.

The DIN 40050-9 standard defines IP69K - resistance to water vapor at high temperature and water at high pressure from all directions without harmful effects on the product, dedicated to high-pressure washing environments.

Sustainable development – ​​temperature controllers in the context of ESG

In the context of sustainable industrial development, it is important to use modern technologies for temperature measurement and regulation. Temperature sensors and controllers ensure precise control of production conditions, their main function is to monitor the temperature and adapt it to the requirements of the production process, making it possible to achieve optimal results with minimal energy consumption.

Modern temperature controllers with PID allow for more accurate process control, which translates into energy savings and reduction of CO2 emissions. The selection of appropriate equipment is crucial for the efficiency of production processes and environmental protection. It is worth using technical advice from specialists to select the best solutions to meet the individual needs of the company and increase operational efficiency.

The reduced load also reduces wear and tear, which in turn has a positive impact on the life of the device - two positive aspects for TCO and ROI. A high degree of lean in-house manufacturing, ever-increasing levels of automation, consistent supply chain tracking and engineering under one roof are key to its pioneering role in the development of the most energy-efficient temperature controllers currently available on the market.

Summary - why Autonics controllers from the WObit offer

Autonics temperature controllers combine advanced PID control technology with industrial reliability and a wide range of options for adapting to specific process requirements. Auto-tuning functions, comprehensive diagnostics, support for all popular types of sensors and communication protocols, and international certifications make them the optimal choice for Polish production plants striving to increase efficiency and competitiveness.

The investment in precise temperature control pays off by reducing energy consumption, minimizing production waste, increasing operational efficiency and lowering maintenance costs. In the context of growing requirements for sustainability and energy efficiency, modern temperature controllers are becoming not only an optimization tool, but a strategic element of the digital and green transformation of the industry.

The WObit team specializes in the selection and implementation of industrial automation solutions for the Polish industry. Our specialists will help you choose the optimal Autonics temperature controller for your process, perform ROI analysis and provide technical support at every stage of the project.

Call today and find out how Autonics temperature controllers can increase the efficiency of your production.

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