It's Not You, It's Me: How ADI Got IO-LINK and Industrial Ethernet Talking Across the Smart Factory Floor

By Michael Jackson and Chris Stelmar

The second blog in this series showed how to design network-agnostic industrial field devices (sensors/actuators) using IO-Link^® device transceivers. The next step is to design an IO-Link Master to interface these devices with an industrial network (or Fieldbus) for transporting process data from the factory floor to a programmable logic controller (PLC) as shown in Figure 1. This blog discusses industrial communications solutions from Analog Devices which can accelerate the design of a flexible IO-Link Master that allows smart field devices to communicate using a choice of some of the most popular industrial Ethernet protocols. In case you missed it, find the previous blog in this series here.

Figure 1 IO-Link devices connect to industrial Ethernet via an IO-Link Master

Choose a Flexible IO-LINK Master Transceiver

An IO-Link master receives process values from sensors and aggregates them before transmitting them to a higher-level industrial network, while for IO-Link actuators, process values are transmitted in the opposite direction. The number of devices that an IO-Link master can support depends on the number of available ports meaning multiple transceivers may be required in an IO-Link Master design. Therefore, critical design parameters to consider when selecting an IO-Link master transceiver include:

• Number of channels
• Configurability
• Protection
• Ease of integration

Analog Devices’ MAX14819 scores highly across all these headings. This low-power, dual-channel, IO-Link master transceiver is fully compliant with the most recent IO-Link and binary input standards and test specifications. It also includes two auxiliary digital input (DI) channels, while to simplify microcontroller selection it features frame handlers with UARTs and FIFOs for time critical control of all M-sequence frame types. To provide a high level of robustness in industrial environments, the MAX14819 integrates two low-power sensor supply controllers with advanced current limiting, reverse current-blocking, and reverse polarity protection. Figure 2 shows how the MAX14819 can be interfaced to a microcontroller unit (MCU) in an IO-Link Master (with auxiliary power supply and isolation ICs also shown).

Figure 2 Typical (single-channel) application circuit for the MAX14819 master transceiver

Choose a Flexible Industrial Network Interface

Analog Devices’ ADIN2299 RapID Platform Generation 2 (RPG2) Network Interface (Figure 3) is a complete, pretested solution that can be used to manage industrial network traffic. This platform contains everything required for an IO-Link Master to participate in any of the most widely used industrial Ethernet networks including:

• EtherCAT,
• PROFINET® real-time (RT) and isochronous real-time (IRT),
• EtherNet/IP

Apart from industrial Ethernet, the ADIN2299 also supports Powerlink and Modbus industrial communications protocols.

Figure 3 Functional block diagram for the ADIN2299 RPG2 network interface

Designed to operate in a star, line, or ring industrial network topology, this highly integrated and fully tested solution includes a communications controller, a two-port 10/100Mbps Ethernet switch, memory, and physical layer (PHY) transceivers. The ADIN2299 hardware, combined with its software and pre-certified industrial protocols reduces design and debug time by not only providing multiple protocol stacks but also the RTOS, file system, drivers, and TCP/IP.

The MCU in an IO-Link Master can easily connect to this switch platform via an SPI interface (Ethernet and UART interface are also provided) while platform software presents an MCU with a single unified interface for supported industrial protocols, meaning no changes to its own firmware are required. This reduces development time by eliminating the learning curve associated with adding additional protocols. Security is another critical feature of the ADIN2299 - it has a secure boot and secure update feature to ensure that only verified code is executed, reducing possible disruptions in the field caused by cyberattacks. Figure 4 shows the block diagram and a list of recommended Analog Devices’ solutions for a complete IO-Link Master design.

Figure 4 Block diagram and recommended product solutions for an IO-Link Master design

Analog Devices’ EV-RPG2 evaluation kits can be used to verify the communication pathway from an MCU to a PLC (or PC-based tool) before integrating the ADIN2299 into an IO-Link Master design. Customized versions of the kit are available to evaluate EtherCAT, EtherNet/IP, Profinet, Powerlink, and Modbus industrial protocols.

Please visit here for more information on Analog Devices’ IO-Link Master solutions.

Find the last blog post in this series here.