Yes. This feature was added in 2013. Ensure that both the data logger operating system and the SDM-SIO1 firmware are up to date. Using an SDM-SIO1, the data logger can be a Modbus client or server, although the intended and most common use is for client operation. In CRBasic, use the SerialOpen() instruction to configure the SDM-SIO1 interface and the ModBusClient() instruction to issue Modbus commands.