XTB-II Options

Not a fan of the screw terminals, but there is nothing wrong with 'em...

I think you should consider an IEC style chassis mount connector(s)...

Cords are available that'll connect into these - with the correct plugs for the country they're used in, etc. They're small, hopefully not too deep, etc. Look here:

And the same connector works for 120v and 240v... Just label it to indicate voltage, etc.

Your thoughts?

Jack :)

Several people have suggested an IEC connector. I used them on all my custom-built factory-floor ATE, but I just don't like them for this application.

Hopefully, most of these will sell as kits. There is no reason why the kitbuilder can't install whatever he wants. I need to minimize the amount of work required for any that I assemble myself. The printed circuit board has almost twice as many components, and there is a microcontroller to program. A round hole in the case and a terminal strip soldered into the PCB is quick and easy.

Jeff

Jeff,

I am still trying to understand why you don't offer an XTB that can amplify any X10 signal on the line as apposed to being limited to only those plugged into it. I'm honestly not criticizing, but here's my reasoning:

1. Yes, there are current amplifiers, but they are low power units.
2. Since I would have several sources of X10 signals, HA controller, CM11, RF receivers, etc, all of which need amplification, but could not be located in a central location for practical operational purposes, the current design of the XTB would require multiple units.

Is there some technical/legal reason why you couldn't produce a unit like the new XTB II unit that received, amplified, and retransmitted the amplified signals from either leg of the power system?

This to me would be the ideal design.

This would be a unique, and superior, product and not just another me-to > I finished initial schematic capture for the XTB-II. It will not be a

Thank you for the suggestion. I have been kicking that idea around, but I'm not sure I want to venture into that can of worms.

What you describe is the normal repeater function. There are plenty of repeaters now in the marketplace. I used the Leviton 6201 myself with limited success. It worked well in our last house, which was smaller, and had X10 devices on both phases. Here we have all X10 devices on the same phase, and the 6201 didn't significantly increase signal levels beyond those of an unaided TW523. Other repeaters may be capable of higher output levels.

There are a couple of excellent articles on repeaters written by Phil Kingery. Here is one that deals with dim/bright commands:

The XTB amplifies the signal received on its X10 input receptacle on a cycle-by-cycle basis. There is no delay or re-broadcast. It is just a high-energy version of what is received. The simple plug-in unit obviously drives just one phase. But the XTB-II will help those who are willing to relocate their main X10 line interface adjacent to their electrical distribution panel.

XTB-II status:

Routing has been completed. The board is 4 1/4 x 3 1/2. Including the future TW523 emulation, it will have twice as many components as the plug-in XTB. Prototype boards will be ordered after additional checking.

Jeff

XTB-II Status:

To anyone interested, the XTB-II component positioning has been added to:

Jeff

Nice layout Jeff. I look forward to building a couple soon.

Jeff Volp wrote:

The XTB-II prototype will be assembled next week, and the kit should be available in a few weeks. As described here before, the XTB-II will have an internal terminal strip for connection to the AC line. It needs connections to both phases and neutral. It should also have a ground connection to pass through to the X10 receptacle on the cover. The strain relief for the AC input will accept up to .4" diameter powercord.

While it would work, I recommend against using a standard 250V 3-wire receptacle, and just jumpering the ground and neutral together inside the XTB-II.

The L14-20R and L14-20P are 125/250VAC 3-pole 4-wire locking connectors appropriate for this application. The XTB-II will be fused at 2 amps, so #18 4-conductor SJ cord is sufficient for the interconnection. 4-conductor SJ cord may be difficult to purchase locally, and I am considering buying a spool to offer by the foot to anyone who wants to connect the XTB-II in the recommended manner. The stuff is expensive, and I will only provide it if there is sufficient interest.

Is anyone interested? Should I also offer the L14 connectors?

Jeff

| The XTB-II prototype will be assembled next week, and the kit should be | available in a few weeks.

Just curious, are you driving the two legs in phase or out of phase?

Dan Lanciani ddl@danlan.*com

In-phase, just like a passive coupler would do.

Jeff

I wanted to update my response to this old thread. I just completed a significant enhancement to the XTB-II firmware. It now includes user programmable mode options so it can be tailored for best performance in each installation. One of the options now available is a limited repeater capability:

I'm not sure you have really addressed Dennis' question. I think he wants an amplifier that boosts any X-10 signal in real-time. According to SmartHome one of their signal boosters does this.

I am familiar with their unit. As you know, the TW523 returns data to the host controller during the last 11 cycles of each X10 command. When enabled, that is when the XTB-II transmits repeated data to the powerline. So the boosted signal is transmitted bit-synchronous with the second copy of each normal X10 command. I believe that is how most repeaters work.

Because the 120KHz bursts are not phase-locked, this approach can result in destructive cancellation of that second copy on the original transmitter's circuit. However, any receivers on that circuit should respond to the unaltered first copy from that transmitter. Since the XTB-II would normally be driving at the electrical distribution panel, its output would override the original transmitter's signal on all other circuits.

Jeff

| I am familiar with their unit. As you know, the TW523 returns data to the | host controller during the last 11 cycles of each X10 command. When | enabled, that is when the XTB-II transmits repeated data to the powerline. | So the boosted signal is transmitted bit-synchronous with the second copy of | each normal X10 command. I believe that is how most repeaters work. | | Because the 120KHz bursts are not phase-locked, this approach can result in | destructive cancellation of that second copy on the original transmitter's | circuit. However, any receivers on that circuit should respond to the | unaltered first copy from that transmitter. Since the XTB-II would normally | be driving at the electrical distribution panel, its output would override | the original transmitter's signal on all other circuits.

This seems to be the unstated (except occasionally by me :) theory behind most repeaters. Sometimes I wonder, though, how probable it would be to have a pathological case where the level heard by a particular receiver from a transmitter is below the receiver's threshold, the level it would hear from the repeater is above its threshold, but the difference between the two signals is again below its threshold. Operation could then depend on the relative phase of the two free-running oscillators in the transmitter and repeater, and that could lead to some head scratching--especially if the levels shift in and out of the pathological ranges as other parts of the network change.

Problems like this would presumably be more common with sub-optimal repeater placement, but I don't think that's required. If the repeater and transmitter are electrically close (even if the repeater is at a service panel) while the receiver is distant from both the transmitter and repeater (and/or is on a high-attenuation circuit) I think you might see such an effect.

It's fairly tricky to set up good tests to observe X10 carrier interference problems and I'll bet that the vendors don't do much in this area. I suspect that it's also fairly easy to fool yourself as I once did when I thought I could get multiple RF->powerline transceivers to coexist. With two transmitters and a receiver plugged into a power strip you may well never see a problem (I didn't.) simply because the transmitter levels are high and the unit-to-unit variations are enough that the difference in level is still above the receiver's threshold.

Dan Lanciani ddl@danlan.*com

transmitter's

I don't think that would happen. Assuming the repeater is at the distribution panel, then the signal from the remote transmitter must be strong enough to get that far. So receivers on its own circuit should have sufficient signal to detect the first half of the message. When the repeater transmits during the second half of the message, it should dominate at the distribution panel, and on all circuits other than the one feeding the remote transmitter. Some receivers on that circuit could get a corrupted second half, but they should have already accepted the good first half.

One case where this would not be true is when the "remote" transmitter is very close to the distribution panel. In this case, that transmitter signal should be similar in strength on its own phase to the output of most common repeaters, and the first half of its message should propagate through the house just as well to devices on that phase. The second half of the message can be corrupted on the transmitter's phase due destructive cancellation, but the repeater's output should be OK on the second phase.

Jeff

In article , snipped-for-privacy@msn.com (Jeff Volp) writes: | | "Dan Lanciani" wrote in message | news: snipped-for-privacy@news1.IPSWITCHS.CMM... | > In article , | "Jeff Volp" writes: | >

| > | I am familiar with their unit. As you know, the TW523 returns data to | the | > | host controller during the last 11 cycles of each X10 command. When | > | enabled, that is when the XTB-II transmits repeated data to the | powerline. | > | So the boosted signal is transmitted bit-synchronous with the second | copy of | > | each normal X10 command. I believe that is how most repeaters work. | > | | > | Because the 120KHz bursts are not phase-locked, this approach can result | in | > | destructive cancellation of that second copy on the original | transmitter's | > | circuit. However, any receivers on that circuit should respond to the | > | unaltered first copy from that transmitter. Since the XTB-II would | normally | > | be driving at the electrical distribution panel, its output would | override | > | the original transmitter's signal on all other circuits. | >

| > This seems to be the unstated (except occasionally by me :) theory behind | > most repeaters. Sometimes I wonder, though, how probable it would be to | > have a pathological case where the level heard by a particular receiver | > from a transmitter is below the receiver's threshold, the level it would | > hear from the repeater is above its threshold, but the difference between | > the two signals is again below its threshold. Operation could then depend | > on the relative phase of the two free-running oscillators in the | transmitter | > and repeater, and that could lead to some head scratching--especially if | > the levels shift in and out of the pathological ranges as other parts of | > the network change. | | I don't think that would happen. Assuming the repeater is at the | distribution panel, then the signal from the remote transmitter must be | strong enough to get that far. So receivers on its own circuit should have | sufficient signal to detect the first half of the message. When the | repeater transmits during the second half of the message, it should dominate | at the distribution panel, and on all circuits other than the one feeding | the remote transmitter. Some receivers on that circuit could get a | corrupted second half, but they should have already accepted the good first | half. | | One case where this would not be true is when the "remote" transmitter is | very close to the distribution panel. In this case, that transmitter signal | should be similar in strength on its own phase to the output of most common | repeaters, and the first half of its message should propagate through the | house just as well to devices on that phase. The second half of the message | can be corrupted on the transmitter's phase due destructive cancellation, | but the repeater's output should be OK on the second phase.

What if we look at it from a receiver's point of view? Say the receiver has a threshold of 50mV and that it normally hears the repeater at that level, giving reliable operation. Assume it can also hear (but not act on) a transmitter on another circuit at 25mV. Depending on the relative phase of the carriers won't it see between 25mV and 75mV during the repeater's retransmission of that particular transmitter? It obviously won't respond to the first copy, so operation may appear random for that particular transmitter/receiver pair. I'm making all the usual linearity assumptions so superposition works, and I'm ignoring variable loading of the repeater itself (this may be important, but since some vendors' designs don't unload when not driving anyway...).

Of course, the above values are chosen to provoke a worst case, but they aren't all that different from what I had before I started adding filters and such. And we are talking pathological situations.

Dan Lanciani ddl@danlan.*com

That's what I thought and was the issue that first brought me to CHA.

My experience is that when the transmitters were very close or very remote, there wasn't much problem but if the transmitters were just close enough so that their transmissions would both arrive at a receiver at different strengths, particularly marginal ones, the fun began. Things actually got infinitely worse when I add a Decora AHT to the mix since it seemed to have either collision avoidance or a transmission pattern somehow different enough from the TM-751's that there were issues. It caused a terribly frustrating problem with the Hawkeye controlled bathroom light turning on and then off about one second later. Boy, did THAT have low SAF! The Decora is now removed and the occasional bathroom light instant turning off problem is thankfully gone with it.

As I understand it, there's no guarantee that each TM-751 will begin receiving an RF command and begin transmitting to the powerline absolutely simultaneously. Judging by what the Monterey showed, one or the other units would begin early, resulting in collisions at a point in the house where both signals were received. I suppose that's due to long button presses, marginal RF reception and human body interference because it was sensitive to people moving around.

I assume that if the second TM-751 was even one half cycle off in hitting the powerline, the two transmissions would "step on" each other. Since the problem seemed to get worse when my wife was home and moving around the house (perhaps blocking good reception at the second transmitter momentarily or maybe emitting anti-proton beams) it had to be fixed. I doubt if two transmitters on the same strip would be subject to that kind of problem - they would see the RF command virtually simultaneously every time.

Thank God for the XTB - now I don't need to use TM-751 as a poor man's repeater - the XTB signal is strong enough to couple the phases at the power pole, or at least that's the conclusion Jeff and I came to.

I have a TM-751 for each housecode I use and they are all routed through XTB's for amplification. The TM's are located nearest to where they will be receiving RF. The one for the driveway is concealed along the top edge of the living room window and oriented horizontally. It *mostly* covers the driveway. (-: Every once in a while, nothing I do will activate the porch light from 50 feet but it always happens in bad weather so I've been reluctant to debug it. I just activate the keyfob a little closer to the house. We have good streetlights so it's not an issue. Other TM's are placed accordingly and it's very rare now that I see the dreaded "BSC/BBK" codes on the Monterey analyzer that indicate a collision or otherwise failed transmission.

Say, did you ever set up your mast mounted WiFi-finder cam?

-- Bobby G.

RF receivers have to be about 1200 miles apart for the arrival times of the RF codes to be off by 1/2 cycle of the 60Hz.

TM751s on opposite phases will _ALWAYS_ transmit 1/2 cycle out of step on unit codes 1 & 9, guaranteeing PLC collisions. On the same phase, you can have as many as desired (at least to the point where multiple PLC transmitters attenuate the signal too much).

For 120kHz cancellation the signals have to be 180° out of phase _AND_ of equal amplitude at the receiver. Otherwise, you see a change in duty cycle but you still see a 120kHz signal. It is not a real world issue! If it were, Insteon, which depends on 180° phase shifts in the 131.65kHz carrier would not work.

What I am trying to describe is a situation where two TM751's *don't* receive the RF command simultaneously. For example, I had one unit placed on the floor to receive signals from the basement. When my wife moved around in front of it, a press of a Palmpad on the first floor would generate a flood of "Bad blocks" on the Monterey and we could even occasionally get a device on another housecode to fire. My belief is that her body acted as a shield for the RF and the TM751 that was in her "shadow" didn't receive the button press until she had moved out of the way. The RF transmission in the house is marginal, and depending on who is where and how they are moving, isn't it at least conceivable that one TM751 sees the RF a slight moment later than the other whose transmission path had no temporary blockage?

I can't be sure of the cause, but the Monterey clearly showed the strength of each bit received and when transmitters were colliding you could see, in the signal dissect mode, voltage levels that precisely matched the standalone value of each transmitter for different bits along with what appeared to be constructive interference, i.e. a signal level for some bits that was a combination of both voltages. I'd run some tests except I don't have collisions anymore and if my wife found out I was inducing them for study, she'd divorce me. (-:

Yes, I read through and through that trying to solve the bathroom "flash" problem. The Leviton unit shouldn't have interfered with any of the TM751's but it did. Badly. Or else it was inherently defective, which is not out of the question.

I'll buy that for sure! How many RF commands are sent with a one second push of a PalmPad button? Just five or does it send as long as you hold down the button?

-- Bobby G.