Yes. The CR1000 could be set up as a SDI-12 sensor using the SDI12SensorSetup() instruction. Alternatively, the CR1000 could be set up to perform serial communications with the CR3000 by connecting a COM1─COM4 port pair and ground from one data logger to a COM1─COM4 port pair and ground on the other data logger. The COM1─COM4 port lines need to cross RX to TX and vice versa.