How Analog Devices Enables IO-LINK and Industrial Ethernet to Communicate on the Smart Factory Floor

The second blog post in this series describes how to design network-agnostic industrial field devices (sensors/actuators) using IO-Link® slave transceivers. The next step is to design an IO-Link master to connect these devices to the industrial network (or fieldbus) and transmit process data from the factory floor to the programmable logic controller (PLC), as shown in Figure 1. This blog post explores Analog Devices’ industrial communication solutions that can accelerate the design of flexible IO-Link masters that enable smart field devices to communicate using the more popular Industrial Ethernet protocol. If you have not read the previous blog post in this series, click here.

Figure 1. IO-Link slaves are connected to Industrial Ethernet via an IO-Link master

Choose a flexible IO-LINK master transceiver

The IO-Link master receives the process values ​​from the sensors and aggregates them before transmitting them to the higher-level industrial network, while the IO-Link actuator transmits the process values ​​in the opposite direction. The number of slaves that an IO-Link master can support depends on the number of available ports, which means that an IO-Link master may need to be designed with multiple transceivers. Therefore, the key design parameters to consider when selecting an IO-Link master transceiver include:

► Number of channels

►Configurability

► Protection

►Easy to integrate

The MAX14819 from Analog Devices excels in all of these areas. This low-power, dual-channel IO-Link master transceiver is fully compliant with the newly released IO-Link and binary input standards and test specifications. The device also includes two auxiliary digital input (DI) channels, and to simplify microcontroller selection, it also features a frame processor with UART and FIFO for time-critical control of all M-sequence frame types. To provide high robustness in industrial environments, the MAX14819 integrates two low-power sensor power controllers to provide advanced current limiting, reverse current blocking, and reverse polarity protection. Figure 2 shows how the MAX14819 connects to the microcontroller unit (MCU) in the IO-Link master (the auxiliary power supply and isolation IC are also included in the figure).

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

Choose a flexible industrial network interface

The ADIN2299 RapID Platform Second Generation (RPG2) network interface from Analog Devices (Figure 3) is a complete, pre-tested solution for managing industrial network traffic. The platform contains everything an IO-Link master needs to participate in any widely used industrial Ethernet network, including:

►EtherCAT;

►PROFINET® Real-Time (RT) and Isochronous Real-Time (IRT);

►EtherNet/IP;

In addition to industrial Ethernet, ADIN2299 also supports Powerlink and Modbus industrial communication protocols.

Figure 3. Functional block diagram of the ADIN2299 RPG2 network interface.

This highly integrated and fully tested solution is designed to operate in star, linear or ring industrial network topologies and includes a communication controller, a dual-port 10/100Mbps Ethernet switch, memory and a physical layer (PHY) transceiver. The ADIN2299 hardware, combined with its software and pre-certified industrial protocols, not only provides multiple protocol stacks, but also RTOS, file systems, drivers and TCP/IP, thus reducing design and debugging time.

The MCU in the IO-Link master can be easily connected to the switching platform via the SPI interface (Ethernet and UART interfaces are also provided), and the platform software provides the MCU with a unified interface that supports industrial protocols, so there is no need to change its own firmware. This eliminates the learning curve associated with adding additional protocols, which can shorten development time. Security is another key feature of the ADIN2299. The device has secure boot and secure update functions to ensure that only verified code is executed, which can reduce the risk of field interruptions caused by cyber attacks. Figure 4 shows a block diagram of the complete IO-Link master design and a list of solutions recommended by ADI.

Figure 4. IO-Link master design block diagram and recommended product solutions

Before integrating the ADIN2299 into an IO-Link master design, the communication path from the MCU to the PLC (or PC-based tools) can be verified using the EV-RPG2 evaluation kit from Analog Devices, Inc. Customized versions of this kit can be used to evaluate EtherCAT, EtherNet/IP, Profinet, Powerlink, and Modbus industrial protocols.