Data Logger from Parallax FTDI based support UART(CTS/RTS Hardware Flow Control) & SPI Interface.
I use Arduino Mega , So I have extra Serial IO to access Terminal & Data Logger.
The Catch is on the WRF command.
PS.It operate under SPI mode,too. That will be faster. Will test latter.
PS.Thanks George Lejnine who give me a chance to review my poor documented code again.