Communication Protocol

Speed	Distance	Noise Immunity	Inter-connectivity

The I2C communication protocol is offered in I2C LCD, I2C VFD, I2C OLED and I2C TFT displays. I2C, or Inter Integrated Circuit, is a half-duplex hardware protocol that uses two conductors, one clock (SCL) and one data (SDA) line, to connect two or more devices. One device, designated the master, uses the clock signal to synchronize data transfer to one, or multiple, slave devices at speeds up to 400 Kbps. Typical logic levels are 5V or 3.3V for a high bit, and 0V for a low, making this an attractive option for embedded applications. I2C supports multiple slave devices by providing each with a one byte read and write address. Networks for this protocol typically span short distances due to a lack of robustness to noise.

I2C is available on Intelligent, and Economy Displays.

Speed	Distance	Noise Immunity	Inter-connectivity

The USB communication protocol is offered in USB LCD, USB VFD, USB OLED and USB TFT displays. USB, or Universal Serial Bus, hardware protocol uses a single pair of differential conductors to transmit data at speeds up to 12 Mbps. It uses logic levels of 5V and 0V, which are favourable for embedded applications, and the cables are typically shielded which provides good robustness to noise. This hardware protocol supports multiple devices over mid-range distances, typically up to 5 meters.

USB is available on GTT, Intelligent, and Economy Displays.

Speed	Distance	Noise Immunity	Inter-connectivity

The Serial or RS232 communication protocol is offered in Serial LCD, Serial VFD, Serial OLED and Serial TFT displays. RS-232 or Serial, Electronic Industries Association (EIA) Recommended Standard 232, is a full duplex hardware protocol that uses one dedicated line for transmitting data (Tx) and one for receiving (Rx). This protocol provides point to point communication between two devices at relatively long distances: up to 50 feet at 9.6 Kbps. Differential signaling, typically +/-12V, provides some robustness to noise and communication speeds up to 32 Kbps. This common protocol is versatile enough to be used in a variety of applications.

RS232 is available on GTT, Intelligent, and Economy, displays.

Speed	Distance	Noise Immunity	Inter-connectivity

The RS422 communication protocol is offered in RS422 LCD, RS422 VFD, RS422 OLED and RS422 TFT displays. RS-422, or Electronic Industries Association (EIA) Recommended Standard 422, is a full duplex hardware protocol that uses two pairs of differential conductors, one set for transmitting (Tx) and one receiving (Rx). These differential pairs are often twisted to travel long distances, up to 1,500 meters, with good robustness to noise, which make this protocol attractive for industrial applications. This multi-drop protocol can support multiple slave devices on one bus at speeds up to 500 Kbps. Implementing an addressing scheme, such as RS485, over RS422 hardware protocol allows the creation of a multi-point network design.

RS422 is available on GTT and Intelligent displays.

Speed	Distance	Noise Immunity	Inter-connectivity

The TTL communication protocol is offered in TTL LCD, TTL VFD, TTL OLED and TTL TFT displays. TTL, or Transistor-Transistor Logic, hardware protocol is a low, non-differential voltage version of RS-232 protocol. Typically, a voltage of 5V or 3.3V is used for high logic, while low logic is 0V. These lower voltages favour embedded applications, but make the protocol less robust to noise. As a result, TTL applications are typically implemented over shorter distances than RS-232.

TTL is available on GTT and Intelligent displays.

Speed	Distance	Noise Immunity	Inter-connectivity

Parallel hardware protocol uses 4bit, 8bit or 24bit RGB interface to conductors to transmit byte length commands at 3.3V or 5.0V logic levels. This protocol is typically used over short distances, between micro-controllers and peripherals in embedded applications. Due to the amount of state that must be transmitted in a parallel conversation, this basic protocol can suffer from slow speeds.

Parallel is available on Parallel Displays.

Speed	Distance	Noise Immunity	Inter-connectivity

Matrix Orbital offers a number of HDMI TFT modules for easy HMI systems. HDMI, or High-Definition Multimedia Interface, hardware protocol uses four twisted pair conductors to transmit visual information at up to 4 Gbit/s. This point to point protocol can stretch up to 15m between two devices. Transition minimized differential signalling (TDMS) provides good robustness to noise and the ease of implementation of HDMI protocol makes it ideal for providing fast visual updates in embedded and industrial applications alike.

HDMI is available on HTT Displays.

Speed	Distance	Noise Immunity	Inter-connectivity

Matrix Orbital EVE2 and EVE3 SPI TFT displays offer a value TFT HMI. SPI, or Serial Peripheral Interface, protocol uses four conductors to enable full duplex, multi drop communication between two or more devices. One signal (SS) is used to select a single slave device for communication, one signal (SCK) is used to clock synchronous transmissions, and two signals (MISO and MOSI) are used for communication to and from the master device. This protocol often utilizes 3.3V or 5.0V logic levels, at rates up to 30MHz, which makes it extremely popular for embedded applications. Furthermore, dual and quad variants of this protocol can improve data transfer speeds with minimal conductor additions. While communication distances for SPI are often short, less than ten feet, the unidirectional signals it uses allow for galvanic isolation, which can be beneficial in industrial applications.

SPI is available on EVE2 and EVE3 Displays.

Matrix Orbital offers a large selection of industry standard communication protocols for our displays. Choose from the list below, or contact us to help you decide.

	Speed	Distance	Noise Immunity	Inter-connectivity
I2C					View I2C Displays
USB					View USB Displays
RS232					View RS232 Displays
RS422					View RS422 Displays
TTL					View TTL Displays
Parallel					View Parallel Displays
HDMI					View HDMI Displays
SPI					View SPI Displays