[slinkelist] Is S-Link Useful on SONY Televisions

Paul Chambers bod@bod.org
Sat, 18 Sep 1999 11:09:03 -0700


At 12:34 PM -0600 9/16/99, Stewart Schilling wrote:
>
>I'm about to shop for a new TV and I see that some SONY TVs have the S-link
>interface.
>Has anyone used this and if so, what have you done with it.  I haven't
>really thought about the possibilities, but if you can give me some uses, It
>might help me to make my decision (Sony with S-Link, or other TV brands).

Let's see if I can recount my understanding of the situation. If I 
get something twisted, I'm sure someone will jump in to set things 
straight.

There are two control protocols that Sony has referred to under the 
'S-link' banner.

One is called Control-A1, which is a bidirectional protocol that 
allows the device to be queried about its state, confirmations to be 
issued when a command is executed, state changes in the device to be 
sent as they occur, etc. All good stuff, and the sort of control that 
makes CDJ possible.

The second is called Control-S, and is an older, unidirectional 
protocol (you may also hear the older term 'SIRCS', which is very 
similar). This is very similar to the protocol that a Sony remote 
control uses to control a device. It only allows commands to be sent, 
there's no means to check the state of the device, or even get 
confirmation that the command was received and executed correctly. 
This is known as an 'open-loop' control protocol, since there's no 
feedback to ensure the right thing happened.

To make things a little more complex, Control-A1 can transport 
Control-S commands, i.e. it is a superset, in a sense. But there's 
still no feedback from Control-S commands, even when sent via 
Control-A1. Confused yet?

As to Sony TVs, my experience has been that they only provide a 
Control-S output. That means it will only send out commands that it 
receives from Sony remotes out on the Control-S connection. It's 
possible that my information is dated, since I haven't had chance to 
look at the latest model range, but to my knowledge, their sets do 
not support being controlled via Control-A1 (a real shame). A 
spot-check on their web site wasn't very conclusive; their 65" HD set 
had a Control-S input and output, but the other products just said 
'Control-S Interface: yes', which doesn't say if it's an input, 
output or both.

My advice is to check the back of the set(s) you're considering, and 
look for either a Control-S input, or Control-A1 connection (though I 
think the latter is very unlikely - let me know if you do find one!). 
If the set has either, Slink-E can control it directly via a wired 
connection. Otherwise, you'd have to use a stick-on IR emitter from 
Xantech with the Slink-E.

Another issue to be wary of in selecting your TV is whether there are 
separate IR codes for turning the set on, off, and select an input 
directly.

All sets have a a power 'toggle' command - send it once to turn the 
set on, again to turn it off. If the set has discrete 'on' and 'off' 
codes, you can use them in macros to ensure that the set is on, 
without the danger of switching it off. Similarly, if you want to 
create a macro to select input 2 on your set (to play a DVD, for 
example) it's much easier if the set has a code to select that input 
directly. Not all manufacturers have IR codes to select an input 
directly - some have just an input button, that cycles through the 
inputs.

Just to make life interesting, just because there are no buttons on 
the remote to select a given input, it doesn't mean the set isn't 
able to do it. Almost all manufacturers implement the same set of IR 
codes for all the sets (of a given model year at least, barring 
features the set doesn't have, like dual-tuner PIP). So all the Sony 
sets will respond to the direct input selection codes, even though 
they may have saved a few cents on the remote by omitting the actual 
buttons to send them. It's worth asking the sales person in the store 
to let you try a remote from the top-of-the-line model on the set 
you're looking at.

For more collective wisdom, and advice on which manufacturers sets 
are easiest to control, I'd suggest looking at the 
http://www.remotecentral.com/ (Pronto forum) and 
http://www.prontoedit.com/ sites. Ask for advice in the Pronto forums 
there. Pronto owners are a friendly crowd, and will be able to offer 
good advice.

Paul
(proud father of the Pronto :-)

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