MAXREFDES62#: RS-485 for uPLC

Industry 4.0 marks the fourth industrial revolution, characterized by distributed, intelligent control systems. Breaking from a past with large, centralized programmable-logic controllers, Industry 4.0 allows for highly configurable, highly modular factories that accept an ever-increasing number of sensor inputs and operate at a higher output than before. The ultra-small PLC, or Micro PLC, lies at the heart of the Industry 4.0 factory, providing high performance with ultra-low power consumption, in an ultra-small package. The MAXREFDES62# is Maxim’s micro PLC RS-485 communications card.

The MAXREFDES62# features two RS-485 transceivers (one full duplex and one half duplex) with isolated power and data. Each driver output has a selectable 120Ω termination resistor.

The MAXREFDES62# design integrates:

• one half-duplex RS-485 transceiver (MAX14783E)

• one full-duplex RS-485 transceiver (MAX14789E)

• 600VRMS data isolation (MAX14850)

• a STM32F1 microcontroller

• a FTDI USB-UART bridge

• and isolated/regulated +3.3V power rails (MAX17498C/MAX17515)

The entire system typically operates at less than 500mW and fits into a space roughly the size of a credit card. While targeted for industrial and micro PLC applications, the MAXREFDES62# can be used in any application that requires high RS-485 data rates and ESD protection.