my %config = (
    '00' => {
        'unpack' => "x40A8",
        'fields' => [qw(Var1)],
    },
    'A0' => {
        'unpack' => "x2A9x3A3x3A42A30",
        'fields' => [qw(Var1 Var2 Var3 Var4)],
    },
);

while(defined(my $line = <$INFO>)) {
    my $segment = substr $line, 0, 2;
    if(exists $config{$segment}) {
        my @fields = unpack $config{$segment}->{'unpack'}, $line;
        my %record;
        $record{$config{$segment}->{'fields'}->[$_]} = $fields[$_] foreach (0..$#fields);
        print Dumper(\%record), "\n";
    }
    else {
        die "ERROR: Unknown segment '$segment'. Config or data error?";
    }
}