UART

UART (Universal Asynchronous Receiver-Transmitter) is a widely used serial hardware communication protocol that plays a crucial role in industrial communication and automation systems. It facilitates reliable and efficient data exchange between various electronic devices, sensors, controllers, and other components within industrial environments.

UART is an asynchronous communication protocol, meaning that it does not require a shared clock signal between the transmitting and receiving devices. Instead, it relies on start and stop bits to synchronize the data transmission. The data is transmitted serially, one bit at a time, over a single communication line.

UART is extensively employed in industrial control systems, enabling communication between programmable logic controllers (PLCs), microcontrollers, and various sensors and actuators. It allows real-time monitoring, control, and data acquisition in applications such as manufacturing automation.

UART operates by converting parallel data from a microcontroller into a serial form for transmission and then converting received serial data back into parallel form. This data exchange occurs via two primary lines: the Transmit line (TX) sends data, while the Receive line (RX) receives data.

Data is transmitted in framed packets that include a start bit, a series of data bits (usually between 5 to 9 bits), an optional parity bit for error checking, and one or more stop bits to signify the end of a packet. The 'asynchronous' designation arises because UART does not require a shared clock signal between the transmitting and receiving devices. Instead, both devices must agree on common settings such as baud rate (the speed of data transmission measured in bits per second), data bit length, parity, and stop bits.

UART's popularity in industrial communication springs from its simplicity and reliability for low-speed data transfer. Unlike more complex protocols, UART does not require sophisticated clock synchronization, making it easier to implement and manage. This asynchronous nature, coupled with minimal overhead, makes UART an ideal choice for many embedded systems where resources are often limited.

• Asynchronous Communication

  UART operates asynchronously, meaning it does not require a shared clock signal between the transmitting and receiving devices. Instead, it uses start and stop bits to synchronize the data transmission. This feature allows devices with different clock speeds to communicate effectively, which is crucial in industrial environments where various devices may operate at different frequencies.

• Simple Frame Structure

  It Indicates the beginning of a data packet. It is a low signal that alerts the receiver to start reading the incoming bits.: Usually 5 to 9 bits that represent the actual data being transmitted. It is used for error detection. It can be configured for even or odd parity.

• Full-Duplex Communication

  UART supports full-duplex communication, meaning it can transmit and receive data simultaneously. This is achieved using separate lines for transmission (TX) and reception (RX), allowing for efficient and continuous data exchange, which is essential for real-time monitoring and control in industrial systems.

• Configurable Baud Rate

  The baud rate, which determines the speed of data transmission, can be configured according to the application requirements. Common baud rates include 9600, 19200, 38400, 57600, and 115200 bits per second. The flexibility in baud rate selection allows for optimizing data transfer rates based on the specific needs of the industrial application.

• Error Detection

  UART can incorporate basic error detection mechanisms using parity bits. The parity bit helps in identifying single-bit errors during transmission, ensuring a level of data integrity. While not as robust as some other protocols, this feature provides a simple and effective way to detect errors in industrial communication.

• Low Overhead

  Compared to more complex communication protocols, UART has relatively low overhead. This makes it suitable for applications where bandwidth is not critical but reliable communication is necessary. The simplicity of UART reduces the processing load on the devices, which is beneficial in resource-constrained industrial environments.

• Versatility and Widespread Adoption

  UART is widely supported across various microcontrollers, communication modules, and embedded systems. Its versatility allows it to be used in numerous applications.

• Microcontroller

  UART is extensively used for communication between microcontrollers and peripheral devices. This includes sensors, actuators, and other control modules. The simplicity of UART allows for straightforward integration and reliable data exchange, which is crucial for real-time monitoring and control in industrial systems.

• Industrial Machines

  In industrial environments, UART is commonly used to facilitate communication between different pieces of machinery and control systems. This includes CNC machines, robotic arms, and conveyor systems. The use of UART ensures robust and reliable communication, which is essential for the precise operation and coordination of industrial equipment.

• Human-Machine Interfaces (HMIs)

  UART connects microcontrollers to display units or touchscreens, enabling the implementation of user interfaces in industrial control panels. This allows operators to interact with machines, monitor system status, and input commands, enhancing the usability and functionality of industrial systems.

• Smart Metering

  In smart metering applications, UART is used to communicate between microcontrollers and metering devices. This facilitates the collection and transmission of consumption data, enabling efficient energy management and billing in industrial settings.

• Automotive Electronics

  UART is employed in automotive electronics to enable communication between microcontrollers, sensors, and entertainment systems. This includes engine control units (ECUs), advanced driver assistance systems (ADAS), and infotainment systems, ensuring seamless operation and integration of various automotive components.

• Serial Communication Between Computers and Peripherals

  UART is used in serial ports to enable communication between computers and peripheral devices. This includes data transfer and device control, which are essential for various industrial applications such as data logging, system diagnostics, and firmware updates.

• Remote Communication

  UART supports long-distance communication, making it suitable for remote monitoring and control applications. This includes communication between distant computers or control units, enabling centralized management of distributed industrial systems.

UART offers several key advantages for industrial automation and communication:

• Simplicity

  UART is remarkably straightforward and easy to implement, not relying on complex handshaking or clock signals. This simplicity is advantageous for embedded systems and microcontroller-based applications common in industrial settings.

• Versatility

  UART can be used for point-to-point, multipoint, and daisy-chained communication topologies, making it highly versatile across industries like industrial automation.

• Robustness

  UART can withstand challenging electrical environments and noise, providing reliable communication even in less-than-ideal industrial conditions where data integrity is crucial.

• Real-Time Communication

  UART supports real-time communication, suiting applications like industrial control systems where immediate data transfer is required.

• Low Overhead

  Compared to protocols like Ethernet, UART has minimal overhead, making it efficient for low-bandwidth or resource-constrained industrial applications.

As a leading company in the field of industrial communication, Hilscher offers a broad portfolio of technologies and solutions for networking industrial environments and consistently integrates UART as an interface technology in its communication controllers.

This includes a wide range of interface solutions for connecting sensors, actuators and controllers to industrial communication networks. The communication controllers of the netX family form the basis for this. The multi-protocol-capable SoCs can be integrated into automation components as required and their extensive chip peripherals enable powerful, efficient and flexible solutions. A protocol change is achieved by simply reloading Hilscher's own netX firmware. Building on this, the company also offers embedded modules and PC cards in all form factors in order to realise the netX communication interface with less integration effort.

Hilscher also offers a comprehensive managed industrial IoT range under the netFIELD brand. This ranges from edge gateways as an application-oriented computer platform with integrated container management and the Edge OS Runtime running on it to the central cloud portal, via which the docker containers are deployed to the edge devices, through to turnkey containers for communication applications.

Gateways and switches, devices for network diagnostics as well as masters and bridges for the wireless connection of IO-Link sensors round off the automation portfolio.