Issue link: https://resources.mouser.com/i/1512203
25 Engineering a More Sustainable Future | ADI Introduction The 10BASE-T1L is a physical layer standard targeted to industrial connectivity. It offers data rates up to 10 Mbps and power delivery over distances up to 1000 m using a standard twisted pair cable. Low latency and the PoDL capabilities allow devices such as sensors or actuators to be controlled remotely. This article explains how to implement a system composed of a remote host that synchronously controls two or more stepper motors, thereby demonstrating the capabilities of real-time communication over distance. System Overview To begin, Figure 1 shows a schematic of the system- level application. On the host side, the conversion between standard and 10BASE-T1L links is managed by the ADIN1100 and ADIN1200 Ethernet PHYs, while, on the remote side, the controller interfaces with the link using the ADIN1110 Ethernet MAC-PHY, which only requires an SPI peripheral to exchange data and commands. Precise and synchronized motion control is accomplished by using the ADI Trinamic™ TMC5160 stepper motor controllers and drivers that allow the generation of six-point ramps for positioning without requiring any calculation on the controller. Choosing these components also keeps requirements on the microcontroller low in terms of used peripherals, computing power, and code size, allowing the use of a wide range of commercially available products. Moreover, up to a predefined power consumption limit, the entire remote subsystem can be directly powered from the data line, so the media converter board is the only module requiring a local power supply. System Hardware The system is composed of four different boards: X The EVAL-ADIN1100 board features an ADIN1200, 10BASE-T/100BASE-T PHY, used in combination with the ADIN1100 10BASE-T1L PHY to translate messages from one physical standard to the other. It can be configured for different modes of operation. In this project, Standard Mode 15 (media converter) is used. The EVAL-ADIN1100 board also features an integrated microcontroller that performs the basic configuration required for media conversion as well as to read diagnostic information. However, it cannot interact with sent and received messages; this board is completely transparent to the communication. X The EVAL-ADIN1110 is the core of the remote devices' controller. The ADIN1110 10BASE-T1L MAC-PHY receives data through the 10BASE-T1L link and transfers it to an onboard Cortex®-M4 microcontroller via an SPI interface for processing. This board also exposes Arduino Uno-compatible headers that can be used to install a shield to add functionalities to the board. X The TMC5160 shield is a custom-developed board based on the Arduino shield form factor. A single shield supports up to two TMC5160 SilentStepStick boards, and multiple shields can be stacked together to increase the maximum number of controlled motors. All the drivers share the same SPI clock and data signals, but chip select lines are kept independent. With this configuration, two communication modes are possible: if chip select lines are asserted individually, the microcontroller can communicate with single controllers—for example, to configure motion parameters. Instead, by asserting more chip select lines simultaneously, all selected drivers receive the same command at the same time. The latter mode is mainly used for motion synchronization purposes. This board also provides some additional input capacitance to the StepSticks to reduce current peaks at motor startup and to smoothen the current profile during normal operation. This allows the use of PoDL to supply the whole system with a maximum of two NEMA17 motors (with the default setup, the maximum transmitted power is 12 W at 24 V). The board is also used to ease the connection with stepper motors by using screw terminals to make phase outputs from the controllers more accessible. X Two EVAL-ADIN11X0EBZ boards, one for the media converter and one for the EVAL-ADIN1110EBZ, are used to add PoDL capabilities to the system. This board is a plug-in module that can be mounted on the MDI prototyping headers of the evaluation boards and can be configured for both supplying and receiving power from the data line. Figure 1: A system overview. 1