I2C (Inter-Integrated Circuit) is a multi-master, multi-slave, single-ended, serial bus invented by Philips Semiconductor (now NXP Semiconductors). It is typically used for attaching low-speed peripheral ICs to processors and microcontrollers.
I2C can be used to control a wide range of devices: analogue-to-digital and digital-to-analog converters (ADCs and DACs), LCD and OLED displays, keyboards, LED and motor drivers, memory chips and cards (EEPROM, RAM, FERAM, Flash), pressure and temperature sensors and other peripheral devices.
I2C bus specification describes four operating speed categories for bidirectional data transmission:
a bit rate up to 100 kbit/s
a bit rate up to 400 kbit/s
Fast-mode Plus (Fm+)
a bit rate up to 1 Mbit/s
High-speed mode (Hs)
a bit rate up to 3.4 Mbit/s
One more speed category, Ultra-fast mode (UFm), stands for unidirectional data transmission up to 5 Mbit/s.
DLN-series adapters can operate in Standard, Fast and Fast Plus modes.