I have been playing with a handful of micro SD cards that I had lying around. They were all formatted using SD Card Suite. I tried them in the V350, and also in SD adapters in the V570. My very limited results to date are that 4GB Kingston and 2GB Transcend cards worked great. However, the 2GB Sandisk cards did not work. The PLC simply does not recognize the card. They work fine in a PC card reader. Does anyone have either a formal recommendation or informal information about which cards work well?