Data Center Boom with Redfish-Enabled PLCs
Unitronics PLCs are game-changers in the massive data center control market—the only PLCs that speak native Redfish, the universal protocol for data center management, no gateway or bridge required. These PLCs can simultaneously run common automation tasks, control complex cooling loops, and communicate with infrastructure components via the universal data center management protocol—Redfish.
The Data Center Boom
The explosion of AI, IoT, and cloud services is driving a massive demand in the market for data centers, and the biggest surge is the need for advanced cooling technologies. According to a recent Frost & Sullivan study “data center cooling revenue is expected to increase from $8.20 billion in 2020 to $18.50 billion in 2030 at a CAGR of 8.5%.”
Cooling is crucial because when greater amounts of data are processed, the data center components consume more energy while generating greater amounts of heat—heat which can damage delicate components.
In addition, individual electronic components need to operate within their optimal temperature ranges; when temperatures rise, the internal resistance rises as well; component performance can suffer while overall power consumption increases. Dissipating heat is therefore critical on several levels.
According to a recent report sponsored by the U.S. Department of Energy’s Federal Energy Management, approximately 40% of data center energy consumption is devoted to cooling. Thermal management strategies, cooling design and equipment selection are essential and so older, less efficient technologies such as computer room air conditioners and evaporative cooling are being phased out, replaced by methods such as Direct Liquid Cooling (DLC), where the liquid coolant is circulated directly through server racks.
Another growing trend is Liquid Immersion Cooling, where servers are submerged in a dielectric liquid, to cool the hardware efficiently. AI is also integrated into data center management systems; algorithms analyze sensor data to dynamically adjust cooling processes. This ensures that energy is used efficiently while maintaining ideal operating conditions for servers. This reduces both energy costs and the carbon footprint of data centers.
What is Redfish?
Redfish is a universal protocol that standardizes communication between the data center components produced by multiple manufacturers.
At its core, Redfish is a simple, scalable, web-based RESTful communication protocol designed to simplify communication between the data center management platform and the equipment installed in it. This allows all data center components—servers, cooling systems, and power equipment—to speak to the data center management platform through a single interface.
Via Redfish, users can automate maintenance tasks such as setting power thresholds, perform remote recovery procedures, collect system and event logs, respond to warnings and critical events, and more.
Below is a diagram of the resource tree, starting at the Redfish Service Root, containing all resources used to model a rack-based Cooling Distribution Unit (CDU). Other types of cooling systems, such as immersion cooling units, follow the same model. 
The Redfish CoolingUnit schema supports different types of gear, such as Cooling Distribution Units (CDUs), connected through Cooling Loops that service the equipment in a single rack. Cooling Loop definitions contain product information and show the connections to and from the loop. This enables software to follow the flow of coolant through its entire cycle in a facility-level cooling system as well as providing basic inventory functions.
Redfish-embedded Unitronics PLCs—Managing Cooling Loops
PLCs can both control coolant flow and regulate temperature. PLCs typically use protocols like Modbus, Profibus, or EtherNet/IP for industrial communication. PLCs from other manufacturers then require a communication bridge or gateway to translate industrial protocols into Redfish-compliant RESTful commands.
Unitronics’ Redfish-embedded PLCs do not need a gateway. Their UniStream Built-in series of controllers exchange data directly in real-time with the data center’s IT management systems via Redfish. UniStream PLC can, for example, report coolant temperatures, pump statuses, or alarms via Redfish, receive an IT Server HTTP GET request to the /redfish/v1/Thermal endpoint and respond with a JSON payload containing thermal information.
Here are a few example of how integrating Redfish with UniStream PLCs can effectively control data center cooling:
- Real-time Control: UniStream PLCs excel at managing the immediate, real-time operations of cooling systems, reliably controlling physical hardware such as adjusting fan speeds, controlling cooling units, or managing liquid cooling pumps, ensuring that cooling is precisely matched to the current thermal load.
- Sensor Data – Redfish-PLC integration: Redfish collects data from environmental sensors across the data center, such as temperature, humidity, and airflow rates; UniStream PLCs can access this sensor data via the Redfish API to determine the current thermal conditions within the data center.
- Remote Management: UniStream PLCs can remotely control cooling equipment via Redfish for real-time adjustments. This can include commands to adjust airflow, activate cooling zones, or change the power state of cooling equipment.
- Environmental control: Via Redfish, UniStream can directly monitor and control environmental conditions, such as temperature, humidity, and power distribution.
- Actions and alarms: via the Redfish API, UniStream can harvest real-time data from data center hardware components—and use it to trigger specific actions based on predefined conditions, for example adjusting cooling systems or raising alarms if the temperature exceeds a specific threshold.
- Data Collection and Analysis: Redfish provides a wealth of information about data center hardware. UniStream PLCs can collect this data over time and analyze trends, which can be used for predictive maintenance, optimizing power usage, and improving overall efficiency.
- Datalogging: UniStream PLC can log data for compliance and auditing purposes, ensuring that all actions taken within the data center are recorded and traceable.
The Bottom Line
As the only Redfish-embedded PLCs, Unitronics’ UniStream PLCs revolutionize data center control, bringing you the following benefits:
- Interoperability & Integration: Via Redfish, our controllers can control data center cooling units, manage cooling loops and other equipment, monitor conditions, and effortlessly communicate with the management software. This level of control was previously only available for large-scale IT hardware.
- Flexibility: Redfish-embedded UniStream can handle a broad range of cooling methodologies including:
- traditional real-time control of fan speeds, power distribution, conditionally turning servers on and off.
- liquid cooling technologies such as direct-to-chip and immersion.
- Competitive Advantage: As the only Redfish-embedded PLC in the market, UniStream stands out in the data center industry, enabling streamlined, integrated, and future-proofed solutions—a distinct advantage in data center management.
Data center technology is rapidly evolving, and the cooling market is enormous and growing rapidly. The 2024 report by Goldman Sachs Research forecasts that US data centers will use 8% of US power by 2030.
Leveraging Redfish protocol together with Unitronics’ UniStream PLCs puts you at the forefront of this booming industry, enabling cutting-edge control that meets tomorrow’s challenges today.
Complete information regarding Redfish is available in the Redfish Data Model Specification, maintained by the DMTF (formerly known as the Distributed Management Task Force). The DMTF creates open manageability standards spanning diverse emerging and traditional IT infrastructures including cloud, virtualization, network, servers and storage. Member companies and alliance partners worldwide collaborate on standards to improve the interoperable management of information technologies.
