For the present, I'm testing with a dummy variable (time in seconds). Eventually, I want to interface the Nano-10 to legacy plant e.g trade waste systems that currently run PLC's capable of Modbus RTU and in effect provide a Pachube logging gateway function through the Nano-10. The variables of interest would be pH, temperature, tank levels etc. The other alternative I am considering is one of the Arduino boards with Ethernet/SD card logging and RS485 ports which are also able to log to Pachube type services inexpensively. The Nano-10 having all the basic interfaces and with 24V I/O appears more attractive in industrial context