Displaying texts on LCD Display (ReadyNas 214/204, OS.6.0.xxx)

Hi everyone!
I made s small shell scripts to display texts on LCD display of ReadyNas 214 or 204, OS 6.xxx. for usage in shells scripts running on RN 214/204 SSH Conn's. Name it as you want.
MSG is the first par, containing text (seems to be usage for all encodings), Duration is in second, UNK is an unknown par and should be always empty...
Example: lcdtext.sh "rsync is finished" 20 ""

#!/bin/bash
MSG="${1}"
DURATION="${2}"
UNK="$3"
if [[ -z "$UNK" ]]; then
UNK=478
fi
/usr/bin/rnutil rn_lcd -s "$MSG" -p 1 -e $DURATION -k $UNK
exit 0