You can upgrade the Firmware by calling

GETUHFINFO<CrLf>

The decoder responds with: 

GETUHFINFO;Region[;FrequencyIndex,Caption]0..<Count-1><CrLf>

Where

<Region>	Is the configured UHF region. Empty if unavailable.
<FrequencyIndex>	Index of the availbale frequency setting. Use this to set the frequency.
<Caption>	Caption of that frequency setting.

Protocol version

Available since protocol version 2.8