Repeater

X10 Booster / Repeater The X10 protocol was developed back in the 70’s by Pico Electronics. Many of us got started in home automation using those ear...
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X10 Booster / Repeater

The X10 protocol was developed back in the 70’s by Pico Electronics. Many of us got started in home automation using those early X10 devices. In the decades since then our houses have become filled with various electronic devices, some of which are downright hostile to X10 powerline communications. People often blame the X10 devices when their system does not work perfectly. However, maybe the blame should be redirected at the manufacturers who developed these new devices without any regard for other equipment that might share the same powerline. X10 Transmit Boosters give X10 systems a means to fight back. X10 powerline control signals are sent as a series of 120KHz bursts coupled onto the powerline. Many X10 transmitters utilize inexpensive transformerless power supplies. While small and cheap, transformerless supplies cannot deliver much energy. Most X10 transmitters output about 5Vpp to the powerline, but that level falls off rapidly as the distance from the transmitter increases. Because most X10 transmitters cannot supply much current, any "signal suckers" on the powerline will compound the attenuation. The normal approach to combating the effects from problem devices is to isolate them with filters. However, many loads are dynamic, and the powerline environment is always changing. It becomes impractical and expensive to isolate all potential problem loads with filters. The X10 BR provide an alternate means to deal with the multiplicity of problem loads by boosting the X10 signals to much higher levels.

OVERVIEW The X10 BR accepts inputs from just about any X10 transmitter. A control module such as the CM15A can be plugged directly into the X10 Input, and the X10 BR will drive boosted output. The X10 BR also includes built-in TW523 emulation. A digital I/O line can be run from an automation controller directly to the X10 BR. The opto-isolated digital interface on the X10 BR is functionally similar to that of the TW523. The X10 BR can directly boost the output of a plug-in X10 transmitter while running in the TW523 emulation mode, and also operating as a highpower repeater. TW523 emulation in X10 BR differ from an actual TW523 in several regards. Normally, the X10 BR error checks all incoming data, and does not produce any output when a collision is detected. Error detection in the X10 BR is enhanced because it not only checks for the correct number of “1” bits in a command, it also checks that all bits are received in complimentary pairs. That should improve rejection of erroneous messages caused by noise from compact fluorescent lights and similar electronic devices. Both units do not need a gap to separate X10 messages, and they will recognize each pair of bright/dim commands. They will also transmit and receive extended commands through both the X10 Input receptacle and the digital port. The X10 BR now includes the ability to repeat the "doublet" extended commands produced by the CM15, HomeVision, and possibly some other controllers. Standard "simplex" extended commands are not repeated because of the overlap issue. A special diagnostic mode is included in the X10 BR that returns all bits just one half cycle delayed from real-time with no error checking. The repeater will function normally even in the diagnostic mode. The X10 BR include a bandpass amplifier for X10 return signals. In addition, the X10 BR includes a gain switch to allow it to receive very weak signals in a relatively noise-free environment, while providing the ability to recover stronger X10 levels in the presence of high background noise. The bandpass filter will attenuate out-of-band noise, but line transients can still make it through, and are amplified. X10 BR PERFORMANCE A typical X10 transmitter, such as the TW523 / PSC05 interface used by many high-end automation controllers, is specified to deliver 5Vpp into a 5 ohm load. The X10 BR was measured delivering just over 30Vpp into a 4.8 ohm resistive load. Since power increases with the square of voltage, the X10 BR can deliver over 30 times the power of a typical X10 transmitter. That will go a long way to combating the many “signal suckers” found in a typical home today. DETAILED FIRMWARE DESCRIPTION X10 BR mode options are programmed by sending a 9-8-2-X sequence via a Maxi Controller plugged into the X10 Input receptacle. Mode programming is accepted only on one selected housecode (P by default). The "ALL-OFF" is still accepted on any housecode at power-on to restore the default configuration. The housecode for mode commands is selected by sending a 9-8-2-2-ON sequence on the desired housecode immediately after an “ALL-OFF” default. The X10 BR offers up to 16 mode options. The X10 BR will always receive extended commands, and the option that disabled that capability has been eliminated. The "TW523" mode has also been eliminated because the X10 BR will accept inputs from any source without requiring a mode change. Since the X10 BR is intended for repeater applications, a fundamental change was made to the operating system so it can operate as a repeater regardless of what other inputs are used. The X10 BR is capable of accepting X10 Boost, digital input, and powerline signals

without mode changes. This allows it to directly boost the output of a plug-in controller, such as the CM15, while simultaneously acting as a repeater. When multiple inputs overlap, the first source received will have priority, and other inputs will be ignored until transmission is completed. There are also options available to abort a transmission when commands overlap, and to re-transmit a repeated command when the line has cleared. These may be useful in certain installations. As part of this change, all X10 BR transmissions are sent using its internal 120KHz frequency generator. That is frequency locked to the 50Hz powerline, and will normally be within 1% of the standard frequency. While the utility company maintains the 50Hz frequency with very precise regulation (even short term), that might be a consideration for people running off independent generators with poor frequency regulation. However, it is doubtful that a generator would deviate enough in frequency to cause a problem with X10 communication. Another significant advancement of the X10 BR is the enhanced AGC loop. The second comparator input of the X10 BR PIC eliminates a possible feedback loop, and incoming signals no longer have to be limited in amplitude. The variable AGC level and alternate AGC sample point provide the ability to deal with noise that will totally block X10 reception by ordinary X10 modules. Bright and Dim commands are a problem for most repeaters because they deviate from standard X10 protocol. They are often sent in sequence with no gaps between. This is a problem for some repeaters, but the X10 BR was designed to repeat sequential bright and dim commands. Since it is impossible to listen to the powerline while the X10 BR is transmitting, the sequence will be repeated copies of the first bright/dim command in the sequence. Like all commands, the first half of the initial bright/dim command is not transmitted because that is received and decoded. The second half is transmitted, as is every subsequent command in the sequence until a gap is received. Because the first half of the initial bright/dim command is not transmitted, the actual number of transmissions in the sequence is always one fewer than the number sent by the remote transmitter. One additional command is not tacked onto the end of the sequence because it could step on another transmission following the bright/dim sequence. Note that a short button press on a maxi-controller produces a half length (ll-cycle) bright/dim command, and the X10 BR will repeat that during the "missing" second half as though it was a standard 22-cycle long command. The X10 BR will receive and transmit all extended commands through both the X10 Input and digital ports. It will also repeat the "doublet" extended commands produced by the CM15, HomeVision, and perhaps some other controllers. It will not repeat "simplex" extended commands due to the overlap issue. Since extended commands have become a standard part of the protocol, the X10 BR does not require a mode option to enable them to be processed. The X10 BR is designed for a 240V single-phase distribution system, and will normally mask the extra bursts produced by some controllers for 3-phase systems. This allows the transmitted power to be concentrated in the essential zero crossing burst. On receiving, the X10 BR always monitors just the zero-crossing signal bursts. Transmitted power is automatically reduced to limit excessive drain on the power supply. There is also a mode option to reduce the output power if the signal strength produced by the X10 BR is too strong for a given installation. The X10 BR provides complete error checking on incoming signals, requiring not only the correct number of 1's, but also that all received bits be complimentary pairs. This is done to fight the modulated noise produced when the noise from multiple compact fluorescent lights sums together. Note that when sending sequential dims, only the first command is error checked because subsequent commands are transmitted copies of that command recalled from memory.

There is a new optional mode that passes ALL received bits back to the automation controller just ½ cycle delayed from real-time without any error checking. This allows an automation controller to actually do collision detection itself. Some controllers may also be able to provide diagnostic information from the raw data bits. While the diagnostic mode is enabled, the X10 BR will still continue to function normally as a repeater. Since the X10 BR was developed for use as a repeater, it includes a feature to automatically disable its transmitter whenever there is a X10 “command storm” on the powerline. This can occur when something causes a remote button to become stuck in the “on” position. Some X10 modules have also been known to lock up in a continuous transmit mode. Since continuous traffic is almost always a result of some error condition, the X10 BR will not contribute its own output into the mix. Some installations may have a lot of normal X10 traffic, and there is a mode command that allows the shutdown threshold to be increased. The default allows a burst of about 120 commands, with 20 per minute average. The higher threshold allows a burst of about 400 commands, and an average of 60 per minute. That should be adequate for even the most complex X10 installations. While the transmitter is disabled, the X10 BR will still monitor traffic on the powerline, and output valid commands to the digital port. The LED flashes continuously while the transmitter is disabled due to a command storm, and the transmitter will automatically be re-enabled after 10 seconds of clear line. Note that the flash mode of the X10 PowerFlash module exceeds even 1 per second, and the X10 BR will go into command storm shutdown after several minutes of continuous flashing. In addition to flashing continuously during a command storm, the LED will provide several other indications. It normally flashes during every received or transmitted X10 command. It can also flicker when line noise manages to peek above the AGC threshold. That normally only happens in the first few seconds after a sudden increase in noise level. The LED will flash 3 times when an error is detected on an incoming signal. That means the X10 BR did recognize a valid start pattern, but there was an error in the data pattern that caused the command to be rejected. The LED will flash 4 times when a collision is detected from overlapping X10 commands on the powerline. Sometimes that can also be caused by a high noise level on the powerline if noise manages to peek above the AGC threshold during a transmitted “0” slot. The LED will flash 5 times if an error occurs during mode programming. MODE OPTIONS PROGRAMING Programming the Mode Options in the X10 BR requires a sequence of X10 commands to be sent using a Maxi Controller plugged into its X10 Input receptacle. Mode commands can also be sent via the digital port. Each key should be pressed for about a second, and the gap between each key press must be less than 4 seconds. The X10 BR only accepts mode programming on the selected housecode (default is P). All programming begins with the key sequence 9-8-2 on the selected housecode, followed by the single key for the parameter to change, and then either ON or OFF. For example, the key sequence 9-8-2-16-ON enables repeater mode. The LED will flash for about a second after the last key is released if the command is accepted. The mode number, and its status ON or OFF is transmitted over both the powerline and digital port so the entry can be logged. The LED will flash 5 times if either an incorrect key sequence is entered or too much time elapsed between key presses.It may be possible to get the X10 BR into a mode where it will not recognize mode commands in a high noise environment. Should this ever happen to you, the X10 BR can be reset to the default configuration by pressing the ALL OFF key on a Mini or Maxi Controller plugged into the X10 Boost receptacle while power is applied after being off at least 5 seconds. The ALL OFF key should be held for about 1 second after the LED illuminates. That normally happens almost immediately, but it can take several seconds for the watchdog timer to trigger if the PIC encounters a problem during initialization. If the PIC does not start quickly, just cycling power again should get it going. The LED will flash again after

the key is released if the default reset is accepted. Normally the X10 BR transmits “P Status ON” when power is applied, and the LED will flash briefly. The user programmable mode options are as follows: (default settings are in parentheses) 16 (on) Repeater Enable 13 (off) Delay Transmit Burst to reduce flashing of nearby dimmers 12 (off) Reduced Transmit Power 11 (off) Auto Retransmit of repeat following collision 10 (off) Abort Transmission on Collision 9 (on) Smart Bright/Dim Repeat for sequential commands 8 (off) Only One Repeat for each command to prevent repeater ping-pong 7 (off) High Command Storm Threshold 60/min. (OFF allows 20/min) 6 (on) AGC Enable (OFF for low gain fixed threshold) 5 (on) High AGC threshold or MSB of fixed threshold 4 (off) Alternate AGC window or LSB of fixed threshold fixed threshold: 5-OFF 4-OFF 150 mV (min) 5-OFF 4-ON 300 mV 5-ON 4-OFF 450 mV 5-ON 4-ON 600 mV (max) 3 (off) Variable Decode enable 2 (P) Housecode for Mode Programming after ALL OFF reset (9-8-2-2-ON) 1 (off) Return All Bits to the digital port with no error checking 16 (ON) Repeater Enable: This option enables the X10 BR repeater function. Like other repeaters, this outputs a high-power transmission in bit-sync with the second half of a received command while those bits are sent out the digital port to the automation controller. 13 (OFF) Delay Transmit Burst: This reduces the potential for dimmer flicker. It delays the zero-crossing transmit burst until just before the X10 reception window. The strong X10 BR signal can induce flicker in some dimmers during transmissions. Delaying the transmit burst appears to reduce or eliminate this effect. This option generates a shorter signal burst, and it should only be used if dimmer flicker becomes a problem. Note: This option 12 (OFF) Reduced Transmit Power: The X10 BR may actually deliver too much signal for some applications, and this option allows the transmit power to be reduced about 40%. Depending on the load, the actual transmitted voltage may not decrease that much. 11 (OFF) Auto Retransmit: This option enables automatic retransmit of a command that was aborted due to a collision. Auto retransmit only works with repeated commands because a collision during a normal transmission would result in that command being corrupted. 10 (OFF) Abort Transmission on Collision: A collision is identified by a burst appearing in the timeslot when no burst is being transmitted. When this option is enabled, the X10 BR will immediately cease transmission of the existing command whenever a collision is identified. This is true regardless of the source of the signal. When a command is being repeated there is an option to retransmit that command after the line has cleared. 9 (ON) Smart Bright/Dim Repeat: Bright and Dim commands deviate from normal X10 protocol because they can be strung together without gaps separating the commands. Dimmer modules interpret bright and dim commands differently, depending on how the commands are strung together. Most repeaters only transmit the second half of each bright or dim command, which can cause them to be interpreted incorrectly. With this

option enabled, the X10 BR will repeat every bright or dim command in a sequence after the first half of the first command. The transmission ends in sync with the last received bright or dim command so that the X10 BR transmission will not conflict with another command closely following that sequence. 8 (OFF) Only One Repeat: When a repeater is used in an installation that has another repeater or certain two-way modules, it is possible for a command to be echoed back and forth continuously. This option prevents that ping-pong effect in those special situations. For example when this option is enabled, only A-1, A-ON will be repeated for the sequence A-1, A-ON, A-ON, A-ON. However, A-1 A-ON, A-1, A-ON will be repeated completely. Because bright and dim commands are a special case, they will all continue be repeated if the Smart Bright/Dim Repeat option is selected. Since the ping-pong effect with 2-way modules does not involve bright or dim commands, this allows the X10 BR to continue handling those commands properly while preventing the ping-pong effect with those modules. This option should only be used if necessary. 7 (OFF) High Command Storm Threshold: The X10 BR will automatically shut off its transmitter when it detects continuous X10 traffic on the powerline. The X10 BR will normally pass a burst of about 120 X10 commands, or 20 per minute continuous. Choosing the High Threshold increases this to a burst of about 400 commands, or 60 per minute continuous. The lower limit should be adequate for most installations. 6 (ON) AGC Enable: This option turns on the Automatic Gain Control (AGC) that adjusts the decode threshold above the background noise level. That allows the X10 BR to dynamically adjust its sensitivity for best performance in a given installation. When disabled, the X10 BR decodes X10 line signals with a fixed, but adjustable threshold. For particularly noisy environments, there are several fixed thresholds available. 5 (ON) Hi AGC Threshold: When AGC is enabled, this increases the threshold another step. This is recommended for noisy environments when incoming X10 signals are strong. This option is on by default to provide the best rejection against possible noise from compact fluorescent bulbs, and can be turned off for better sensitivity if you have a relatively noise-free environment. When using fixed threshold, this bit determines the most significant bit of the threshold voltage. See the following table. 4 (OFF) Alternate AGC window: It was found that the X10 RR501 RF transceiver occasionally does not transmit its third burst in the defined slot. It falls into the beginning of the Insteon window, which is where background noise is normally sampled to set the AGC threshold level. This option allows an alternate sampling slot to avoid this problem. The alternate slot may not be quite a good sampling point, but should be tried when having difficulty receiving signals from either a RR501 or TM751 transceiver. Other units may also exhibit this phenomenon. The alternate sampling point can also be selected for combined X10 systems to prevent the brief reduction in sensitivity immediately following an Insteon transmission. When using fixed threshold, this bit determines the least significant bit of the threshold voltage: fixed threshold: 5-OFF 4-OFF 150 mV (min) 5-OFF 4-ON 300 mV 5-ON 4-OFF 450 mV 5-ON 4-ON 600 mV (max) Note: Low gain is selected when using fixed thresholds for maximum noise margin. Use AGC enabled for maximum sensitivity (mode 6 ON).

3 (OFF) Variable Decode: This option selects a variable decode rather than the X10 standard 48-cycle fixed count to decode a logic one. The variable decode monitors the background noise level for a logic zero, and decodes a logic one when there is a significant increase in cycle count above the average. This option is particularly useful when trying to recover low-level X10 signals just above the noise level. 2 (P) Housecode Select: A 9-8-2-2-ON sequence sent IMMEDIATELY after an ALL OFF powerup default reset will set the selected house code to that used for the 9-8-2-2-ON sequence. The window to accept the housecode select is only open for 4 seconds after the default reset. If the housecode is not changed within that window, the X10 BR will only accept the default “P” housecode for programming mode commands. 1 (OFF) Return All Bits: This option sends all data bits received over the powerline to the digital port without any error checking. Data is only delayed ½ cycle of 50Hz from real time. This option may be useful for diagnostics or for an enhanced automation controller that does its own error checking. However, since no error checking is performed, noise can cause erroneous “1” bits. This option produces half-cycle length data pulses rather than the standard narrow pulses, and may be useful to monitoring equipment. This option should be left off unless needed. ELECTRICAL CONNECTION It should be installed adjacent to the electrical distribution panel. Connections to the distribution panel are made through one of the two internal terminal strips. The other terminal strip is normally connected to the X10 Input receptacle on the cover. The X10 BR should be wired to phase and neutral of 240V/50Hz via 16A or 20A circuit breaker. A standard power cord can be connected to Phase and Neutral. Ground is not used internally. Check the electrical connections carefully before applying power. It is recommended that the terminal strip screws be re-torqued (with power switched off) to insure solid connections.