First, we have some housekeeping chores to take care of.  Many things have happened recently and we need to talk about them. Let’s begin with how we got here.  I began writing these little insights into my psyche way back in 1996 when l was asked if I would be interested in writing something for another website.  I was and I did.  That one article turned into a long series of articles, all of which are stored down in the dark, dank basement here at ACT.  (Don’t worry.  The closely regulated humidity and temperature control keeps the articles fresh and unspoiled.)

 Then, after #13, Digital X-10, in February 1999, the articles stopped and I took a break.  Even though I was not actively writing new articles, all the old articles were still “out there” (or, here, as the case maybe).  I suppose that is one of the strengths of the Internet.  The information is available to anyone who takes the time to search for it.  Even though there were no new articles for almost 2 years, the “old” articles were always “new” to someone.  Hardly a week would go by that I didn’t receive at least a couple
of emails from people who had just discovered the “WOSIU” series.

 October 2000 saw not only the return of the series (#14, subtitled an, “Introduction into 2-way and Extended Code”), but also the first west coast home automation show sponsored by Electronic House magazine.  "EH-Expo",  last October, was a lot of fun.  To those of you in the L.A. area and those of you who traveled to L.A., thanks for stopping by.  It was a pleasure meeting you.  I hope that you
came away with a better understanding of home automation.  The next one will be March 7-10, at the Orange County Convention Center, Orlando Florida.  Plan on attending.  That may seem a long way off, but it is only 3 months away (and I have already been contacted about being a speaker, again).

All right, let’s get on with other business.  The last article was a departure from its predecessors in that it began deviating from talking about the technology and began to showcase more of the new products from Advanced Control Technologies.  It was, however, very well received, which explains the close votes.  (You thought I was kidding didn’t you?)

 Unlike the presidential elections, there is no one looking over my shoulder and demanding recounts upon recounts.  So, although I will tell you which subject got the most votes, it is only because of my reputation and character that you know I am telling the truth.  And the truth is this:  It was a tie.  I’m not joking. 

Here were the choices on the ballot back 2 months ago, listed in reverse order of their votes:

6. Your choice (within reason).  I didn’t receive a single “write-in” vote.  That is probably for the best since I wouldn’t know how to count them.  What would I write about if “Your Choice” received the most votes yet each vote was for a different subject.  There were, however, a few votes for one of the other choices where the voter added some special twist or supplementary request, but I don’t suppose that really counts (like a hanging chad).

2. More on two-way: Wall-mount transmitters which track the state of the receivers they control.   I was surprised that this candidate received so few votes.  In all honesty, it will be hard to write this article without including this subject in some form or another.  (You will see what I mean in a moment.)

4. A tutorial on binary and hexadecimal code notation in relation to X-10 standard and extended code.  This one received quite a few votes, but obviously not enough.  I was secretly hoping that it might win out in the end, because it would probably be the easiest to write. For those of you who know me well, also understand my desire to present foundation knowledge.  Many people may have thought, “I don’t need to know about binary and hexadecimal code, just tell me how I use the new 2-way stuff”. Understanding binary and hexadecimal coding is just about the biggest chunk of foundation knowledge you need to understand any digital technology.  And if you haven’t figured it out yet, THIS stuff is digital.  To those of you who did vote for this subject, I appreciate you recognizing this to be an important step in understanding this technology.  I may still try to hide some bin/hex tutorial information into this article.  We will just have to see how it goes.

 5. What did you really mean when you were talking about "compatibility" and then said, "That in itself is an ongoing battle, but I will tell you more about that in a later article".   Okay, I admit it.  I was baiting you on this one.  A few of you were able to read much deeper into that statement.  Those of you who voted for this one probably have a better understanding than most, of the problems with “compatibility”. Although this preamble is getting to be pretty long, let me open up another Pandora’s Box of sorts. Please understand this; the X-10 protocol is not a “standard”.  There is no governing body who has adopted nor regulates the use of, changes, additions and adherence, to the protocol.  Instead of being a “standard”, it is simply a “published” protocol.  It has been around for over 22 years.  There is a ton of reference material available to anyone who wants to learn about it.   However, as with any complex technology, not everyone who wants to use it will fully understand it, nor will they always agree with it.  As more and more companies begin selling their versions of “X-10 compatible” products, there are going to be compatibility problems.  We have already begun to see it.  And I have to admit this to you; some of the conflict is due to my own interpretation of the published protocol.  The next home automation convention will be at the Spring EH-Expo.  I had asked if they (the organizers of the conference) would consider providing a venue for a round-table discussion at the spring convention.  I have received word from them that if there are enough interested parties, they will provide a place and time at the convention in Orlando.  Email me if you are a manufacturer, distributor or an engineer who has influence or you are interested in participating.  See you in the spring! 

Okay, we are down to the last two choices and since I already told you that they were tied, this should not be any surprise.

1. More on two-way: Receivers which announce their state when manually activated.   And…

3. More on Extended Code: Including New Preset Dim commands, versus the old preset dim commands.

  There is also this thing called a deadline.  You are reading this in December 2000 (or sometime afterward), but I actually wrote it (mostly) just before Thanksgiving.  I am, as I write, in Bermuda trying to keep my mind on this article and not think about the beautiful Bermuda beaches.  (Honest, dear, this really is a business trip! I swear!)  Before I left my office in Indy, I checked my email one more time.  While there was still some time left, I had no choice but to certify this election.  I called my mother in Florida (I figured she was as qualified as anyone) and asked her to break this tie.  Unfortunately, she had no idea what I was talking about. 

Anyway, since I had to make a decision, I decided to combine the two.  Therefore, after almost 3 pages of preamble, this edition is hereby entitled:

Which One Should I Use, #15:

Two-Way Receivers with Direct Dimming and Scenes.

Okay, it took us a long way to get here, but we finally made it.  In this edition, we are going to explore more of the capabilities of some of the newest X-10 compatible dimming receivers. 

ACT (the company that pays my salary) began working on our new line of X-10 compatible devices almost 2 years ago.  We called them “A10”, for Advanced X-10.  The first such devices were geared more for our industrial/commercial customers.  However, as we broadened our new product line, we also wanted to target the residential market.  In an unintentional arrogant sort of way, we knew that what we understood about powerline carrier communications in large, 3-phase, multiple building, multiple transformer systems, would be of great benefit to the guys doing home automation. 

For the past year, we have released a long list of new products.  The one product that is having the biggest impact for us is also proving itself to be the most advanced.  We knew when we designed it that it would be at the cutting edge.  What we didn’t realize is that it may be just a little beyond the cutting edge.  You will see what I mean later. 

As you know, there are 256 addresses in the X-10 protocol (that is 2⁸ or 2 to the 8^th power, if you are into binary notation).  First and foremost, the RD104 conforms to the protocol by being able to use one of those 256 addresses.  This may be a minor point but we decided that since we often find ourselves struggling to do very large installations with only 256 addresses, we decided not to allow any of our devices to use any more than one address at a time.

Why do I bring this up?  PCS make some very clever dimmers that use an alias.  That means that in order to offer their customers some dimming flexibility, they designed their dimmers to respond to more than one address.  That allows their customers to transmit the first, or main address and command for that dimmer, or the customer can send out the second address/On-command (alias) which causes the dimmer to execute a scene.  Many of their dimmer units can store 16 different scenes.  Each scene is executed by sending a different address and “On” command. 

If this is so clever, why didn’t ACT adopt this method?  Although we applaud their creativity, our industrial customers would find themselves quickly running out of addresses if we allowed our units to have more than one of them. 

Okay, where did this leave us?  We had already been working within the published protocol so we figured that we would simply use “Extended Code 1” (explanation can be found at ftp://ftp.x10.com/pub/manuals/xtc798.doc)  to do the same thing.  The published protocol not only allows for, but also explains (but not very clearly) how to send dim commands beyond those in the standard command set. 

This is a good point to review dimming in general. The original X-10 dimmer modules that we all know and love, can be “turned on” in four different ways.  Two of them are pretty obvious:
1.  – The user can send the address and “On” command (that seems the most obvious), or,
2.  – The user can transmit an “All-Lights-On” command (preceded by the right letter code, of course). 

What may not be so obvious is that those dimmers can also be commanded to come on by two other ways. (Remember, I’m still talking about “standard” code, here.)

1.  – The user can transmit the address and the “Dim” command.  If the user is pressing the dim button on a tabletop transmitter (often called a “maxi controller”), the light will pop on at full brightness and then begin to dim as long as the user’s finger is still on the dim button.

2.  – Lastly, the user can transmit the address and the “Bright” command.  If the user is pressing the bright button, the light will pop on but because the older dimmer modules always came on at 100%, holding the bright button does not make it get any brighter. 

I’m not sure if this was intentional or not.  It may have been that the first ASIC (Application Specific Integrated Circuits) from the 70’s simply did this because of ease of design or it could be that the Pico Engineers had several long meetings figuring out if they should or should not do it that way.  In any event, since we felt that most X-10 users would be used to it working that way, we designed our RD104’s to work the same way.

Also remember that when I said “transmit the address and the…”, I don’t mean that both had to happen at the same time.  X-10 receivers have what I call a “ready state”.  When they hear their address, they are “ready” for a command.  If they hear a bunch of other addresses before they hear a command, they still remain in their ready state.  Once they hear a command, they will execute that command right along with all the other receivers (within their letter group) which are also in their ready state.  They will continue to execute commands as long as they remain in their ready state.  Barring a power failure, they will remain in that ready state until they hear another address within their letter group, or an “All-Units-Off” command. 

If this is confusing, think of it like this.  When a drill sergeant yells out, “Soldier #1, soldier #2 and soldier #3!”  You know instinctively that the next command will be for all three of those soldiers. He can then order them to do several things in a row.  “Give me twenty”, then he yells, “Go report for K.P.”.  Both of those orders pertained to those three soldiers.  If he would continue giving orders, we would expect them to be only for those same three soldiers. 

Then he suddenly turns and says, “Soldier #5!” Everyone knows instinctively that the next order will be only for soldier number 5 and not for any of the previous 3 soldiers.  The idea that the “All-Units-Off” command resets all the receivers is like the drill sergeant saying, “Dismissed!”  At that point, none of the soldiers (receivers) will continue in their ready state unless he hears his own address after that.   Such as, “Soldier #4!  Does that make sense?” 

Okay, so we made the RD104 so it would conform to the standard method of turning on when commanded.   But how about the “old” preset dim commands.  Well this is going to take some explanation.  First I have to explain what I mean by “preset dim” and then we will discuss the old version and the new version.

I don’t really like the term “preset dim” at least not the way that the X-10 documentation uses it.  For those of you who do the big fancy (and expensive) hard-wired lighting systems, the word “preset” denotes that the light level has been predetermined or setup before the time that you need it.  It’s kind of like when I buy diskettes (or zip disks) for my computer.  They usually come preformatted.  That tells me that they were done at the factory before I bought them, and I won’t have to format them before using them.  In that same way, the term “preset dim” also denotes that the dim level of that light was predetermined at some time before now.  That sounds more like a “scene” to me.  I think what X-10 really means when they used the term “preset dim” is “direct dim”. 

Okay, I hereby resolve to use the new term “direct dim” to mean sending a single command that will cause a dimmer receiver to go to a specific dim level.  If the dimmer is already brighter than the commanded level, dim down to that level.  If it is already dimmer than the commanded level, go up to that level.  If the dimmer is off, it is to turn itself on and go directly to that level.

Most X-10 users did not realize it but the X-10 protocol always did have the capability of direct dim commands (even though X-10 called them “preset dim” commands).  If you study the X-10 protocol, you will see that the binary command 1010 (which is 10¹⁰ or A¹⁶) was assigned to Preset Dim 1, and 1011 (which is 11¹⁰ or B¹⁶) was Preset Dim 2.  At first glance, this would appear that there were only 2 levels of dimming.  That doesn’t sound very good.  We all know that there are at the very least 16 different dim steps in the original dimmer modules.  (If you were able to send individual dim data frames you could even get what some people called micro-dimming.)   How then, could there have been only two delete preset (or direct) dim steps.

Obviously there were more than 2 levels. There were actually 32 steps or levels.  It worked like this.  Let’s assume that the dimmer you are wanting to control was addressed to A1.  (Now, please understand that I never suggest you really use that address.  Anything you buy, from X-10, X-10 Pro, Leviton, or even us, comes from the factory set to A1.  I do, however, use the address A1 as a literary example.)

Sending A1, A1, A-On, A-On   …obviously causes the dimmer to come “On”.

Sending A-Dim, A-Dim, A-Dim, A-Dim, A-Dim   …causes the dimmer to descend 4 major dim steps.  Five contiguous dim data frames equals four major dim steps.  An easy way to remember this is:

n dim frames = n-1 dim steps.  (It works the same for bright data frames.)

In order to cause the dimmer to go directly to one of 32 different dim levels (0-31), the user could transmit one of these data strings:

A1, A1, M-Preset1, M-Preset1  = 00000 = dim level 0 (0%).

A1, A1, N-Preset1, N-Preset1  = 00001 = dim level 1 (~3%).

A1, A1, O-Preset1, O-Preset1  = 00010 = dim level 2 (~6%).

…through…

A1, A1, L-Preset2, L-Preset 2  = 11101 = dim level 29 (~94%).

A1, A1, I-Preset2, I-Preset 2  = 11110 = dim level 30 (~97%).

A1, A1, J-Preset2, J-Preset 2  = 11111 = dim level 31 (100%).

(And my thanks to Rick Marron <marronrg@hotmail.com> for his help in explaining this).

That’s pretty slick.  By transmitting the address first, we made sure that the receiver would be in its ready state (as well as any other addresses within that letter group that we also wanted to be in their ready state).  Then we would transmit a data frame pair where the command portion would be either 1010 (= direct dim set 1) or 1011 (= direct dim set 2).  When these sophisticated dimmer receivers saw the 1010 or the 1011 command section, they would interpret the letter code as a direct dim level.

Now jump back to WOSIU #13, Digital X-10 and look at the last graphic.  It doesn’t have a label, but it’s below figure 14.  You might want to open a new browser window so you can have this open at the same time.  Go ahead, I’ll wait.

Okay, now you have had a chance to look at that chart.  You will notice that  the binary sequence 1010 is listed as “EXT CODE 3^B – Formerly “Preset Dim (1)”, now designated for security messages”.

What does that mean??

Look again at that chart.  You will also see that  the binary sequence 1011 is listed as “UNUSED“^C – Formerly “Preset Dim (2)””.

This doesn’t appear to be a very good turn of events, now does it.  I have just described how X-10 dimmers could be sent a single command that would cause them to go directly to a specific level without having to hold your finger on the dim or bright button on your maxi-controller, and then I tell you that it is no longer available.  Well, here’s what happened.  The X-10 engineers had these commands in the protocol from the beginning, but X-10 never made any dimmers that could use those commands (as far as I know).  They also feared that sending commands that were not preceded with the correct group letter could be potentially devastating to the reliability of the overall system.

Although you do (because you are a loyal reader of these articles), most X-10 users don’t realize that when communicating to any receiver set to letter code G, for instance, any commands must also be preceded by that same G letter code.  There really is no such thing as an “On” command.  It is G-On, or A-On, or M-On, etc.  If this old “Preset Dim” system was to work, a dimmer receiver would have to figure out that any letter code is okay as long as it is attached to one of the two “direct dim” commands.  And then that letter code would not mean a major letter group, but instead designate a dim level.  Today, new X-10 compatible dimmers can be designed to use those commands, but back in the late 1970’s, it would have been a lot more difficult.

And so X-10 had the ability to do direct dimming in the protocol, but they didn’t make any dimmers that could take advantage of them.  Were there any other companies doing it?  Yes, PCS!  Their dimmers will react to the old direct dim command set.  Another company that took an innovative twist on the idea was RCS, Residential Control Systems. They make a wide variety of thermostats, some of which receive the old direct dim commands for temperature setting.  Pretty inventive.

Technically speaking, however, this older method of sending direct dim commands is no longer recognized by the authors of the protocol. Remember, up a couple of paragraphs I reminded you that the bit patterns that had been assigned to do that old direct dimming are now assigned to “EXT CODE “ and “UNUSED“.  Luckily, something better has taken its place.  Now we have a 64 step direct dimming method which has a lot more reliability because it no longer uses the letter (major group) code as the conveyor of the dim level.

As far as explaining how it works, I won’t go into detail for several reasons.  First, you shouldn’t have to understand it since your computer front-end (StarGate, HAL2000, HAI-Omni, HomeSeer, Magic Module, etc.) should do all the work for you.  Second, this article is already way too long and I have some more stuff I want to cover.

Okay, so now we still have the regular dimming method where you hold your finger on the dim or bright button on your X-10 maxi-controller.  We used to have the 32 step method of direct dimming. Now we have the 64 step method of direct dimming using X-10’s Extended Code.

I am reminded about how Spinal Tap had their amplifiers labeled so they would go to eleven.  “Well, it’s one louder, isn’t it.”  Therefore, just in case there are any misunderstandings, having 8 steps, 32 steps or 64 steps does not mean one method is “brighter” than the one before it.  Having more steps just means there is greater resolution.  I did this chart just to illustrate what I mean.  The blue line only shows 8 steps, yet it is just as bright (high on the chart) as the one with 32 steps, and the one with the 64 steps.

I remember talking to another friend in the industry, Jeff Stein of JDS Technologies.  We were discussing dimming resolution and he and I agreed that no human being can discern lighting steps any smaller than about 6%.  I think that 16 steps of dimming would have been more than adequate for most of us.  Perhaps 32 steps would satisfy the purists.  However, 64 steps may very well be overkill.  Despite that, I also have to say that since I did not write the protocol, I don’t have very much to say about it.  Since we at ACT had already decided to conform as closely as we possibly could to that protocol, we have adopted the 64 step extended code direct dimming method in our new dimmers. Looking into the future, that 64 step resolution will come in handy when we begin sending analog data instead of just light levels.

You can imagine that all this has caused some conflict for us at ACT.  When we designed our newest line of coupler/repeaters, we wanted them to conform to the newest version of the X-10 protocol.  That (at first) meant that our repeaters would not repeat the old (“preset”) direct dim commands.  That decision created a dilemma for us.  How were we to support those products from our associates in the industry who use those older commands if our repeaters would not repeat those older commands?  We couldn’t.  So we decided to change our repeaters.  Since not even X-10 has published the bit string for Extended Code 2 or Extended Code 3, we couldn’t create an algorithm to repeat them anyway, so we don’t.  Instead we made our repeaters able to repeat the older (“preset”) direct dim commands along with the new direct dim commands within Extended Code 1.

Now you have a little better idea about the evolution and revolution with X-10 compatible dimmers.  Now let’s get back to the RD104.  It is a 120V, A10, 600 watt, 2-button, fully X-10 compatible, dimmer receiver. . . and boy does it have some surprises for you.  The first thing you will notice, especially if your only experience has been with devices from X-10, is that the RD104 has no code wheels.  None of our A10 devices have code wheels.  That means we have to configure, or program it, a little differently.  This is what the RD104 can do.

1. It can receive:
    A. Common commands:
        1)  Standard commands like “ON” and “OFF” (pretty basic),
          2)  Plus “Dim” and “Bright” (also basic stuff).

   B.  The standard code “Group” commands:
          1)  Common ones, “All-Lights-On” and  “All-Units-Off”,
          2)  Plus the seldom used “All-Lights-Off”.

    C.  The standard code “Status” commands:
          1)  “Status-Request”,
          2)  and then it can transmit “Status-On” or “Status-Off” in response.

2.  It can also receive:
    A.  Ext’d Code “Direct” dim level commands (64 steps).
    B.  Ext’d Code “Scene” storage for up to 68 scenes.
    C.  Ext’d Code “Status-Request”.
    D.  and then it can transmit its exact dim level (64 steps) in Ext’d Code.

3.  Among its features:
    A.  “Nite Lite” mode (LED reverse action).
    B.  User selectable fade rate.
    C.  Remembered state (goes back to last level).

And that’s just the high lights. Lets go through a quick setup of a new RD104. First, decide on your options:

The options above are the simple ones.  Now you need to decide on the more complex options.

Now that you have decided what you want the RD104 to do, lets set it up to do it.  First, wire up the unit so it has power.  Many installers use a temporary wiring arrangement on their filtered test bench so that they can configure many units in a row.  Don’t worry, they will hold their configuration even without power.

That way, they will be ready to go when you get to the job site.  Just remember to use a marker to note  the address code and options on the RD104 label as you program each one.

Now, you can use any X-10 compatible transmitter capable of separate addresses and separate commands to do the basic configuration.  You can use any transmitter like the Maxi-Controller, but we prefer that you use ours.  We call it the TD100 (and it’s just like theirs).   To do the advanced stuff, you will need something with a little more smarts (but more on that later).

Now press and hold both buttons at the same time, for 3 seconds.  That will put the RD104 into configuration mode.  Now you are ready to tell the RD104 what you want it to do and how you want it to react

That’s it.  It’s done.  Now all you have to do is get out of configuration mode.  There are two ways of doing that.  If you fumble with the instructions long enough, it will time out on its own (one minute) and put itself back into run mode.  (It’s pretty smart that way.)  Or you can simply tap the top button to get it back to run mode.  Did you notice that little asterisk* after setting the fade rate and getting the seven LED flashes?  It is recommended that you always do this option last since you must put the RD104 into advanced configuration mode to do it.  After that, it is difficult to go back and do anything else, except exit the program mode.

Now that it is all done, the RD104 will do what you told it to do and it will react to what you send to it. Plus it is a true two-way transceiver.  It is a receiver!   It receives commands according to how it is configured.

It is a transmitter!  It transmits its status when manually activated or asked.

It is so sophisticated that I don’t know of any standard front-end controller on the market that can take advantage of all its features.  That’s okay, it will wait.  When the front-ends of the HA world catch up to it, the RD104 will be waiting.

------------

Before we go, we need to come up with our choice for the next one.

Here are your choices for "Which One Should I Use, Part XVI":

1. More on two-way: Wall-mount transmitters which track the state of the receivers they control.
2. A tutorial on binary and hexadecimal code notation in relation to X-10 standard and extended code.
3. More on "compatibility" and interpreting the X-10 protocol.

Send your vote to me at pkingery@act-solutions.com. If you have any questions about this article, please let me know.  If you have personal experience with some of the products mentioned in this article, or with a competitor’s product, send that to me also.  If I made a mistake anywhere in this article (yeah, right!) please let me know.

I’ll see you all at the EX-Expo in March 2001.  I will remind you again in our next installment in February. Until then, Happy Holidays.

-"Uncle" Phil Kingery

Phillip Kingery is a representative of Advanced Control Technologies, Inc.
pkingery@act-solutions.com