"SunFlower"™ Sequential Cone-Top Warning Lamps


The pi-Lit® “SunFlower”™ Sequential Cone-Top Warning Lamps are sold and boxed in sets of 10 lamps. 4 AA-Alkaline batteries are already installed into each “SunFlower”™ Cone-Top Warning Lamp. Our universal cone adapters are supplied for each lamp and come with a carrying satchel. 

The “SunFlower” lamps are shipped with 4 AA alkaline batteries installed and ready to use.

We have distributors world-wide.  Where we do not have a distributor close by, we can work with you directly.  Call us 24×7 to discuss color options, battery choice, and general information.  


Turning on and positioning the SunFlower™ lamps

NOTE:  a tap is a momentary press of a button: a hold requires a 3-second press of a button

It does not matter which lampis turned on 1st. They are all identical.  Simply tap (a momentary press) the round On/Off button.  The small red LED will come on indicating that the lamp is turned on and “thinking”.  The 1st lamp will take approximately 3 seconds to begin to flash.  Subsequent lamps will take less than 1 second. All subsequent lamps must be turned on AFTER the preceding lamp is flashing.  If 2 lamps are turned on simultaneously, or too quickly in succession, the algorithm might confuse the numbers.  This can be used to your advantage – more on this later.

First, remember that the radio range between lamps placed atop a traffic cone is greater than 330 meters (1000 feet). So, when using several groups of lamps in close proximity may lead to unexpected behavior.

Second, our recommendations are arbitrary, although based on thousands of hours and hundreds of deployments. We believe the lamps should be placed 7 to 10 meters (20-30 feet) apart, depending upon the speed limit.  The MUTCD calls for delineators to be separated by 1-foot per mile-per-hour which equates to 15-25 meters (50-75 feet). Deployment of 10 lamps in this manner will lead to a sequential string of lamps 150-250 meters (500-750 feet) long.  Most 330 meter (1000 feet) tapers call for 20 lamps, or approximately 15 meters (50 feet) between lamps. While the MUTCD calls for a maximum number of feet between lamps, there is no minimum.  The effectiveness, and hence safety benefit of sequential technology is enhanced with increasing length and number of lamps in a string.

Third, simply tap the power button of the first lamp and place it atop the cone.  Then, after it begins to flash and while still walking tap the power button of the 2nd lamp.  The cones are likely spaced 15 meters (50 feet) apart.  Simple walk the taper and place each lamp atop the cone while turning it on.

Finally, remember that nothing attenuates a radio signal more than a body of water.  That’s why submarines must surface to communicate via radio.  Your body is approximately 80% water content, so if you stand between the lamps as you are turning them on at the limit of its range, you may not find them synchronized correctly.  This is rarely, if ever, an issue during typical deployments, but we provide this information to help you understand this remarkable technology.

Collect the lamps in any order.  We recommend that you allow the lamps to continue to flash while you retrieve them.  Once in your vehicle you can turn all the lamps off by pressing and holding the “Group” button for 3 seconds.  All the lamps will show a red indicator LED while shutting off.

We provided a neat trick for you! Our 1st release of the SunFlower™ lamp did not incorporate this patented feature. While the lamps are flashing in sequence you can simultaneously tap (not hold) the Power and Pattern butttons. Do this on any single lamp, number 7 for example! The flares will reverse the sequential march.  Note that the 1st flare that you turned on is now the last flare to flash.

So, the standard deployment (in default forward direction) requires that the 1st lamp to flash be turned on 1st.  So, you deploy the lamps turning on the 1st lamp farthest from the workzone and move toward the work zone as you turn on subsequent lamps.

Okay, with me so far?  Now, suppose you prefer to deploy the 1st lamp at the work zone and travel towards oncoming traffic as you add the additional lamps.  If you reverse the direction of march and turn the lamps off the system will remember this command.  The next time (and every time until you change it) the lamps will turn on with the 1st lamp on to flash last.  So, now you can turn the 1st lamp on at the work zone and turn on subsequent lamps as you travel towards approaching traffic and the sequence will be correct (in the direction of traffic flow).

Best that you try in the hallway, kitchen, sidewalk, or neighbors yard.

Operating the Sequential Cone-Top Lamp

All Pi-Lit® Sequential Warning Lamps have 5 flash patterns to choose from. Certain patterns might be more effective for a particular application. For instance, a rural dark road where speed is a factor, the fast flash pattern might be better suited to get the motorist attention further upstream.  

The flash patterns may be changed for the entire group of lamps by taping the pattern button on any single lamp. The lamp will send the message to other members in the group. 

Here is a brief descriptions of the patterns:

  • Pattern 1 = Single lamp marching
  • Pattern 2 = Two lamps marching
  • Pattern 3 = “Wave” pattern (lamps tail off from one another creating a smooth pattern)
  • Pattern 4 = Fast single lamp marching
  • Pattern 5 = Simultaneous lamp flash (lamps flash in unison)

The Pi-Lit technology includes photosensors that can distinguish night time from daytime. If regulations do not require 24 hour operation, the battery life can be significantly lengthened by operating during night time hours only. 

To activate the photosensor, tap the 12/24hr button. The green indicator LED will flash once to indicate 12hr operation (nighttime only), or twice to indicate 24hr operation.

Pi-Lit® smart mesh network makes it easy to replace a damaged or low battery lamp. The lamps are smart enough to know where they are positioned in the network and know whether there is a lamp (hole) missing in that string. 

To insert a lamp into the string, first make sure that the lamps are flashing (not in daylight sleep mode). While the lamps are flashing, position yourself to close to where the hole in the string is (where you are replacing the lamp). Tap the “Insert” button on the lamp you are inserting into the string. The green indicator LED will turn on a stay lit while it is searching for the hole. Once it has found the position it is replacing the green LED will turn off and the main LED will begin to flash. The lamp should now be in sequence with the string.

To check if the lamp is in the correct sequence number, while the lamp is flashing, tap the “Insert” button. The green indicator LED will flash indicating the sequence number it is currently in. For instance, if the lamp is the 12th lamp in a string of 20 lamps, tapping the insert button while its flashing, the green indicator LED will flash 12 times. NOTE: The green indicator LED will flash in groups of 5 green flashes for ease of counting. For a lamp that is positioned as number 12, the green indicator LED will flash 5 green flashes, pause, 5 green flashes, pause, 2 green flashes. This indicates lamp number 12. 

IMPORTANT: For situations where there is multiple lamps needing to be replaced, not an issue. To replace a string of lamps with multiple holes, start with replacing the lower sequence number first. For example, if you have a string of 20 lamps and you need to replace lamp numbers 2,5,8,18, begin by inserting your replacement lamp at position number 2, then moving onto position 5, position 8, and finally ending with position 18.

Buttons to adults are like shining things to kids; they have to touch them. To prevent disruption of operation caused by curious fingers, the operator can lock the button “membrane”.  Once locked they buttons will not work.  The LED indicator will flash to indicate that the button was pressed, but no action will take place.

To lock the buttons, tap briefly both the Power and Insert buttons simultaneously.  A red LED will flash to indicate that the buttons are locked.  Tap the same buttons once again and a green LED will flash to indicate that the buttons are unlocked.

PiLit® technology provides the option to flash on one side of the lens, the other side, or both sides. If all the lamps are mounted consistently with the back lens (side with the buttons) facing away from traffic then the front LED can be chosen.  This will reduce by almost half the energy used. Alternatively, if the lamps are mounted with all the buttons facing traffic (back side) then only the back LED may be lit.  Again, this saves energy.  If your team was out late at night, maybe they didn’t pay attention and mounted them in a random fashion, some with front lens and others with back lens facing traffic.  In this scenario, no worries, simply choose both sides to flash.

To choose front, back, or both, simply press and hold the Pattern button.  The default is both sides flashing.  Hold for 2 seconds and only the front will flash.  Press again for 2 seconds and only the back will flash. Finally, hold for 2 more seconds and both sides will flash (default).

Some states require a constant light along with the flash.  This is not called for in the MUTCD, but local requirements may call for it.  No problem.  Tap simultaneously both the Pattern and Power buttons.  The lamp will turn on a steady burn of lower intensity.  The sequential pattern will continue. Note that the battery life is considerably compromised when steady burn illumination is called for. To turn off the steady burn feature, simultaneously tap the two buttons again.

With the lamps deployed there may be need to reverse the direction of sequence.  Simultaneously tap the 12/24 and Group buttons.  The direction of sequence will reverse.  If you turn the lamps off this mode will be stored in memory.  The next time you turn the lamps on the 1st lamp turned on will be the last lamp to flash.

You can turn off a single lamp, or all of the lamps in a given group at once.

To turn of a single lamp, simply press and hold the square power button for 3 seconds.  The flare will flash the red small indicator LED and turn off.

To turn off all the lamps in a group, choose any single lamp, press and hold the group button for 3 seconds, and all of the barricade lamps will flash a red indicator before turning off.

Accordion Content

Battery Status, Changing Batteries, Charging Flares

The Sunflower™ lamp is the only sequential lamp on the market that lets the user check the state of the battery. No more random changing of batteries. Ask the lamp before turning it on!

To do so, when the lamp is either powered off or on simply hold    (3-seconds) the “12/24”-hour button. The green LED will flash 5 times for a full battery, then 4 times, 3 times, then 2 red and then 1 red flash as the battery is depleted. We recommend changing then batteries at 2-red, depending upon the anticipated deployment. We anticipate when using the SunFlower™ lamp in pattern 1 (least energy use); with one-side only flashing; and with nighttime only operation; that the lamp should flash for approximately 1-month.

The SunFlower™ lamp requires 4-AA alkaline batteries. This design choice led to a much lighter weight lamp for crash worthiness atop a cone. Please insert batteries with attention to proper polarity. 

Yes, you can use lithium rechargeable batteries if you prefer.  Please contact us to discuss the details.

Group Changing

The Pi-Lit® system uses 2.4-GHz radio signals to communicate, coordinate, and synchronize the sequential or simultaneous flashing.  Depending upon the product and deployment, the range can be up to 330 meters (1000 feet).  If you deploy a set of lamps on one side of the highway and another vehicle or work area is on the other side, they may be within radio range.  Hence, if your colleague on the west side decides to take an early 02:00 am break and turns off her lamps, she may inadvertently turn yours off as well.  Or she may prefer a different flash pattern.  So, we provide different Groups (frequencies) that you may choose to either allow the lamps to work together in a super long string (unlimited), or to insulate your Group of lamps from others in the area.  All lamps, regardless of color, in the same Group will synchronize.

Within our spectrum of 2.4-GHz we have 15 channels to use.  We reserve 5 for our road construction products (SunFlower™ and Barricade-style, and 5 for the ICS™ flare.  If you have a special need for more Groups (frequencies), give us a call and talk nice.

For the Sequential Barricade Warning Lamps the group channels are represented by the case color. This makes it easy for crews to replace lamps deployed on the road. Whenever a lamp needs to be replaced, all the personnel in the field needs to do is call a colleague in the warehouse and say we need to replace an orange sequential lamp on this project. The warehouse personnel grabs a new orange lamp off the shelf and sends it out to the project. Once it received by the personnel on the road, all he or she needs to do is insert the lamp into the string a that’s it! 

Group Channel Colors:
– Group Channel 1 = Yellow Case
– Group Channel 2 = Orange Case
– Group Channel 3 = Blue Case
– Group Channel 4 = Gray Case
– Group Channel 5 = Reserved for custom colors

Okay, progress marches on.  We have improved this feature, which is described in the next section.  For legacy products (After September 1, 2018), here is what you do:

For products delivered before September 1, each lamp must have its Group number changed individually.  This must be done while the lamps are off.  They must turn on listening to the proper frequency, so this action must be done with the lamp in the off state.  (Some people say that I repeat myself, that I say the same thing over and over again, that I am redundant).

With the Pi-Lit® Sequential Barricade Warning Lamp, with the lamp off, simply tap the “Group” button.  The green indicator LED will flash the current group the lamp is in. For example, if the lamp is currently in group channel 3, the green indicator will flash 3 times. Once it has indicated which group the lamp is currently in, you are now in Group change mode. If you do nothing after the initial green LED flash the group change mode will timeout and a red indicator LED will flash 2 times. The red indicator LED flash indicates that the group state is saved and it is now exiting group change mode. The lamp will now go back to sleep.  So any action must take place before the double red flash.  Again, to enter Group change mode tap the “Group” button when the lamp is off.  The green LED will flash indicating the current Group number.  Now, tap (not hold) the “Group” button. Each tap of the “Group” button will increment the Group number.  Tap the button twice and you have chosen Group 2. Tap the “Group” button five times and you have chosen group 5. Oops, made a mistake.  Quickly tape the  button again 4 “Group” button and you will see the green LED echo back 4 flashes to tell you that you have chosen Group 4.  Oops, I meant Group 3, so tap the “Group” button 3 times and the green LED will echo back your choice of Group 3.  When finished, simple wait 3 seconds and the lamp will flash red twice and go to sleep.  It stores the Group change until you decide to change it again.  You have 5 Groups to choose from.  All the barricade lamps in the set, or at least all that you want to work together must be in the same Group number.  If ever you find that the set of barricade lamps does not seem to sink correctly, first check that all the lamps are in the same Group number.

To be implemented into the Pi-Lit® Sequential Barricade Lamps shortly 



The patented Pi Variables, Inc. technology uses the I.S.M. (Industrial, Scientific, Medical) 2.4GHz band. The Pi-Lit® product line is FCC compliant.  The radio “stack” or protocol is not Bluetooth, ZigBee, or Wi-Fi, but similar.

Indeed.  All of our products utilize a “System on a Chip” (SoC) with microprocessor (computer) and radio transmitter and receiver all on a single silicon wafer.  This component is FCC compliant and our circuit design has been tested by two independent laboratories confirming that spurious signals and radio-frequency output energy fall within strict FCC guidelines, and that the device is immune from external radio-frequency interference.

The maximum recommended deployment distance between lamps is 100 meters (330 feet). This distance allows for variation in radio frequency energy between lamps, multi-path transmission noise (signal bouncing off trucks, vehicles, etc.), weather (rain may attenuate the signal), line-of-sight obstruction, etc.  The actual line-of-sight is closer to 300 meters (1000 feet), but remember, placement must take into account that one or two lamps may be struck by vehicles and the two closest lamps must pass the signal down the string.  So, if a lamp is struck the two adjacent lamps must be less than 300 meters (1000 feet) apart.

The Sunflower lamp is designed for cone-top deployment and is of lighter weight than the bolt-on barricade style lamp using D-cell batteries. The 4 AA-alkaline batteries of the Sunflower will provide 1 month of operation with single side flash and night-time only.

The MUTCD is equivilant to the Bible for traffic control and traffic safety devices. All road projects, big or small, must follow the rules set forth in the MUTCD. Section 6F.83 permits the use of sequential flashing warning lamps on taper/delineator . Please view the below PDF to take you to section 6F.83 of the MUTCD.

Federal MUTCD 2012 6F.83 Sequential


On occasion your computer goes bonkers.  It is rare but the same may happen to the Cone-Top Lamp. After all, the micro-controller is a sophisticated computer. You can reboot the lamps computer by either removing one of the alkaline batteries and pressing buttons for a few seconds. This will remove power from the micro-controller and effectively reboot the product.  Pressing a button when the batteries are out will discharge the capacitors on the circuit board.  Capacitors help to filter the battery voltage.  The SunFlower™ uses so little power when off that the capacitors will provide voltage to the micro-controller for 1 minute or more even without batteries or power.  Pressing a button discharges the capacitors.

We recommend cleaning the lens of the Cone-Top Lamp periodically. This will enhance the brightness of the lamp by removing any of the road dirt or grunge. 

To clean the lens use a rag or paper towel and apply simple green to the lens. Rub down the lens with pressure to remove any dirt or grunge that is adhered to the lens. 


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