RTU is an abbreviation for Remote Terminal Unit, also known as Remote Telemetry Unit or Remote Telecontrol Unit. A remote terminal unit (RTU) is a microprocessor-based device that monitors and controls field devices before connecting to plant control or SCADA (supervisory control and data acquisition) systems.
RTUs transport sensor data from input streams in control loops to an output stream to be carried on to centralized control in an ICS. In addition, RTUs automatically establish connections to local or distant controls.
This blog looks at understanding the basic functions of RTUs, units of an RTU, and its various applications.
How Does an RTU Function?
RTUs transform electronic signals received from (or required by) field instrumentation into (or from) the communication protocol used to send data over a network. RTUs are visible in the field as a switchboard box with electrical signal wires flowing to field instruments and a cable connected to a communication channel interface, such as a telephone cable, a field bus, or a radio.
Because the limited bandwidth of communication links to the SCADA central host makes central storage unfeasible, the instructions for the automation of field data interface devices are often kept locally. Such instructions were formerly stored in local electronic devices known as programmable logic controllers (PLCs), which were physically independent of RTUs.
Even before the SCADA system, RTUs were utilized for remote telemetry with integration to the central computer in the early stages.
RTUs were hardwired devices that were electronically intended for specific functions, such as responding to serially received numeric codes at the time. As a result, the first remote terminal units were designed to receive and transmit current input and status information and generate contact outputs based on the control message.
Units Of an RTU
- CPU: Nowadays, the built-in central processing unit employs a 16-bit or 32-bit CPU with a memory capacity of 256 kilobytes. The system has three communication ports with ethernet cables, and the real-time clock governs it. In addition, the employment of a watchdog timer allows for real-time monitoring of process operation. This watchdog timer is reset regularly, and if it is delayed, the timer flags an error.
- Module of Power Supply: The RTU requires a continuous power supply for uninterrupted operation. However, the unit is located far from where the collection is present. As a result, an alternate power supply with battery backup is provided to the team to ensure continued functioning during a power outage. Solar panels are commonly utilized for low-power RTUs. However, thermoelectric generators are also used depending on the availability of gas pipes.
- Analog Output Model: These include visual recording tools and strip charts used to cope with changing amounts. DAC is used to convert the digital value obtained from the CPU into analog form. This analog representation also controls the actuators.
Applications Of an RTU
RTUs are found everywhere ICS is utilized and are part of the systems used in a variety of operations, including:
- Refineries and petrochemical plants
- Atomic power plants
- Agriculture
- Quality assurance
- Plants that produce chemicals
- Plants for sewage treatment
- Manufacturing of automobiles
- Pharmaceutical production
- Plants for water treatment
Connect With a Reliable Service Provider
You can maintain great situational awareness and respond perfectly to remote threats using the information acquired by your RTUs.
However, no two RTUs are alike. There are numerous models to choose from when designing your monitoring system. If you purchase fewer capacity and sensor inputs than you require, you will not have a clear view of your network condition after deploying your brand-new design. This is dependent on the RTUs you choose to deploy at your sites and the vendor you decide to buy from. To make an informed decision, you should always buy from remote monitoring professionals, as quality can vary greatly between manufacturers.
“Creator. Troublemaker. Hardcore alcohol lover. Web evangelist. Extreme pop culture practitioner. Devoted zombie scholar. Avid introvert.”