The MAXREFDES145# is a fully IO-Link®-compliant, 8-port IO-Link master reference design. This design uses TEConcept's IO-Link master stack and is both an IO-Link master reference design as well as an IO-Link sensor/actuator development and test system. Eight IO-Link ports allow for simultaneous testing of up to eight different sensors (or actuators). The reference design has eight robust female M12 connectors, the most common connector used for IO-Link, and ships with two IO-Link cables to quickly connect to IO-Link compatible sensors and actuators. An AC-to-DC (24VDC/1A) power-supply cube is capable of providing at least 125mA simultaneously to each port and more when fewer ports are unused. A USB 2.0 Type B connector allows for quick connectivity to a Windows® PC.
The easy-to-use TEConcept Control Tool (CT) GUI software with IODD file import capability makes the MAXREFDES145# a must-have for any company or engineer serious about developing IO-Link products.
IO-Link is the first open, field bus agnostic, low-cost, point-to-point serial communication protocol, used for communicating with sensors and actuators, that has been adopted as an international standard (IEC 61131-9). IO-Link standardizes interoperability of industrial equipment from all over the world. IO-Link can function directly from the PLC or can be converted from all standard field busses to IO-Link through a gateway, quickly making it the defacto standard for universally communicating with smart sensors and actuators.
IO-Link is a single-drop digital communication interface (SDCI), which means there can only be one sensor or actuator per port. The 3-wire protocol is also backwards compatible with binary sensors and actuators that use standard input output (SIO). IO-Link device descriptor (IODD) files completely define the device and eliminate manual parameterization.
The MAXREFDES145# design utilizes four MAX14819 dual-channel Maxim Integrated IO-Link master transceivers, two on-board digital isolators, the efficient industrial MAX15062B step-down converter, an FTDI USB-to-SPI interface and an STMicroelectronics 32-bit ARM Cortex® M4 microcontroller (STM32F4) utilizing TEConcept’s CT Tool software and IO-Link master stack. Figure 1 shows the system block diagram.
Figure 1. The MAXREFDES145# reference design block diagram.MAXREFDES145# System Board
The MAXREFDES145# IO-Link master consists of 4 main blocks: four dual-channel MAX14819 IO-Link master transceivers, two digital isolators for the SPI interface, a microcontroller, and a USB connection as shown in Figure 1.
The MAX14819 IO-Link master transceivers are IO-Link version 1.1.2 physical layer compliant. These transceivers feature integrated 5V linear regulators, configurable C/Q outputs (push-pull, high-side, or low-side) with configurable output drive capability, auxiliary digital inputs, and reverse-polarity/short-circuit protection.
An STM32F4 ARM Cortex M4 microcontroller in a 10mm × 10mm, 64-pin LQFP package provides system control. A universal serial bus (USB) port is implemented using the FTDI FT2232 USB-to-SPI transceiver and driver. An on-board MAX15062B high-voltage, synchronous step-down converter provides power to the STM32F4 microcontroller from the 24V supply.
Two digital isolators, the 4-channel MAX14931F and the 2-channel MAX12931B, protect the USB interface from high-voltage and large ground differentials that can occur when the MAX14819 master transceivers are connected to IO-Link peripherals. All communication between the USB port/PC and the SMT32F4 microcontroller passes through these isolators.
A stand-alone SPI header (J3) is available on the MAXREFDES145# to allow the user to bypass the USB interface and directly communicate with the STM32F4 using an external SPI master. J3 is connected to the isolated side of the board and all digital communication from the external master to the STM32F4 goes through the isolators. An external 3.3V logic supply to power the isolators is required when using J3.
High-level protection transient voltage suppressor (TVS) diodes at each of the eight IO-Link interface ports and at the power supply inputs provide surge and reverse-polarity protection for each master transceiver on the MAXREFDES145#.
Additionally, power and status LEDs (for each channel) provide quick visual confirmation that the board is working and communicating.
Figure 2. MAXREFDES145# box contents.
The MAXREFDES145# box contents:
MAXREFDES145# 8-Port IO-Link Master
TEConcept IO-Link Control Tool (CT) Software (Note 1)
AC-to-DC 24V/3A (min) Output Power Converter
Two IO-Link cables
USB 2.0 Type B cable
Necessary downloadable software:
TEConcept IO-Link Control Tool (CT) software (Note 1)
Figure 3 shows the MAXREFDES145# system connected to a laptop running TEConcept's CT Tool. The MAXREFDES145# typically consumes 24mA from the 24V supply at 25°C with no sensors attached.
Figure 3. MAXREFDES145# system connected and running.
Detailed Description of Software
TEConcept CT Windows-compatible GUI software features IODD file import capability, connects to a PC through USB, and is available to download from the Design Resources tab. of the MAXREFDES145# webpage. The TEConcept CT software is shown in Figure 4 and a complete step-by-step Quick Start guide is also downloadable from the Design Resources tab.
Figure 4. MAXREFDES145# TEConcept CT tool.
The TEConcept IO-Link master stack ships preprogrammed inside the MAXREFDES145# hardware with an infinite time license displayed by the TEConcept CT software.
The MAXREFDES145# is a fully compliant IO-Link version 1.1 master according to the following test report. It was tested with golden device GD000010. See the test report for details: MAXREFDES145# 8-Port IO-Link Master Test Report in the Design Resources tab
IO-Link is a registered trademark of Profibus User Organization (PNO).
ARM and Cortex are registered trademarks and ARM is a registered service mark of ARM Limited.
Windows is a registered trademark and registered service mark of Microsoft Corp.
Note 2: Maxim Integrated offers multiple IO-Link sensor reference designs for immediate operation with the IO-Link master. Refer to MAXREFDES23#, MAXREFDES27#, MAXREFDES36#, and MAXREFDES42#.
