HOW DOES IT WORK?

N-PLC Click is based on the SM2400, the ultimate Narrow-band Power Line Communication (N-PLC) modem from Semitech that combines cost-effective design optimized for PLC applications with a high level of programmability to address a multitude of communications schemes and evolving standards. The SM2400 system-on-chip (SoC) features a dual-core architecture for dedicated PHY signal processing and MAC layer functionality to guarantee superior communication performance while maintaining high flexibility and programmability for OFDM-based and other open standards and fully customized implementations. It has a set of firmware options implementing IEEE 1901.2 compliant PHY and MAC layers, a 6LoWPAN data link layer, PRIME, G3-PLC, and other special modes tailored for industrial IoT applications.

The SM2400 combines the benefits of programmable architecture with power and efficiency by utilizing a DSP core configured specifically for N-PLC modulations and a dedicated 32-bit core that runs protocols. It contains a high-speed 256-bit AES-CCM engine to ensure standard compliance and secure communication, and all the necessary mixed-signal components, such as ADC, DAC, gain control and two OpAmp to deliver a cost-effective N-PLC system design for any application.

In addition to the SM2400, this Click board™ also includes a PLC line driver, the SGM8423, a high efficiency, Class A/B, low distortion power line driver. It is optimized to accept a signal from a Power Line Carrier modem, for example, one like the SM2400, which is presented in the example code, where two such boards talk to each other in a transmitter/receiver configuration. Besides directly performing enable/shutdown control of the line driver, the SM2400 has one diagnostic signal that can indicate error conditions, such as overcurrent or overheating, reported by the line driver. In addition, it is also possible to supply high voltage (110/220VAC) as an input on the PLC CONN connector, which will be converted into a signal of the appropriate level via the N-PLC Wall Adapter, a simple yet very useful power line communication AC coupling circuit for safe and secure operation. The green PLC PWR LED signal that the N-PLC Wall Adapter is connected and powered.

The SM2400 communicates with an MCU using the UART interface, as its main one, with commonly used UART RX and TX pins and the optional hardware flow control pins UART CTS and RTS (Clear to Send and Ready to Send). The UART interface serves as the primary interface to a host, which can be an MCU or a converter, such as serial-to-USB. As an alternative to the UART interface, users also have at their disposal the lines of the SPI serial interface (to use this interface, it is necessary to populate the appropriate 0Ω resistors to activate the SPI lines).

The SM2400 executes its firmware from internal memory, with the loaded code at a boot time. The SM2400 can boot either from an external SPI flash, the AT25FF041A, or from a host MCU via UART interface depending on the logic state of the MD1 pin of the mikroBUS™ socket (0 - boot over UART interface that allows direct firmware download (boot from the host), 1 – boot from external SPI flash memory), with the host MCU being the Master. In addition, the SM2400 provides the possibility of a reset via the RST pin of the mikroBUS™ socket (asserting this pin causes full chip reset and reboot), as well as visual detection of the communication status via the red PHY LED, which is asserted when an incoming packet is detected.

The power supply of this Click board™ is performed very simply, without any additional hardware configuration (depending on the power supply capability and the desired range). It is possible to power the board in two ways: internally and externally. By default, the board power will be provided internally over the LM5158 boost converter in the value of 15V, which is obtained from the 5V mikroBUS™ power rail. When applying an external power supply of 15VDC on the VEXT terminal, the N-PLC Click will automatically be powered from the external source thanks to the protection of the converter, which automatically recognizes the presence of the external power supply, and gives it a priority.

This Click board™ can only be operated with a 3.3V logic voltage level. The board must perform appropriate logic voltage level conversion before using MCUs with different logic levels. However, the Click board™ comes equipped with a library containing functions and an example code that can be used as a reference for further development.

SPECIFICATIONS