you mean it does only display title and %, but no actual value?

That's what it sounds like to me.  In the code, there is nothing that check's for a valid signal strength before including the wireless signal strength details in _getPlayerInfo.

There is a check on line 179 of SystemInfo (next unless defined $value) that would have gotten rid of the wireless value for wired players ($client->signalstrength is undef when wired), but with '%' added, this now evaluates to true.

Best way may be to have the signalstrength accessor return with '%' already concatenated when needed.

eg...
Squeezebox.pm, line 218:
sub signalStrength {
	my $sig = Slim::Networking::Slimproto::signalStrength(@_);
	return $sig ? $sig.'%' : undef;
}

(In reply to comment #1)
> you mean it does only display title and %, but no actual value?
> 

Yes.

Created attachment 4180 [details]
Only show wireless strength for wireless players

This moves the adding of '%' to the $client->signalStrength method.

I've checked the player ui, web ui and also squeezeplay r3220 and it looks more sensible now :)

change 23749 - hide signal strength when player is plugged in to ethernet

Kevin - I did not add the percent sign in the signalStrength() method as someone (plugin, CLI) might expect a numerical value.

This bug has been fixed in the 7.3.0 release version of SqueezeCenter!

Please download the new version from http://www.slimdevices.com/su_downloads.html if you haven't already.  

If you are still experiencing this problem, feel free to reopen the bug with your new comments and we'll have another look.

Reduce number of active targets for SC