How can this platform be used with protocol based (SDI-12, MODBUS) sensors?

On behalf of Daniel Braunworth:
The platforms shown communicate via UART, I2C, SPI, or SWD (same as the ADUCM355). You could use an additional translator IC, especially for protocols like SDI-12 where the physical layer requires different voltages that the ADUCM355 digital I/O pins.