The ? command outputs a listing of device information.
?<cr>Example:
>?
>Device Name : DMT132 Dewpoint transmitter
Calibrated : "20110223"
Calibration location: "VAISALA/HEL"
Serial number : "G0831004"
Batch number : "G0000007"
Sensor model : "HUMICAP180R"
Sensor serial number: "F312"
Operating mode : 2 Wire
Transmitter status : NORMAL