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Whelen's CanTrol WC Light and Siren System

Emergency vehicle warning systems perform three primary tasks: Warn others of hazards, signal violators to stop, and request right-of-way. It is extremely important for fleets to have standardized warning systems based on an intelligent and practical methodology. Yet, even when the department head, fleet manager, and vehicle upfitter work together to provide a proper, standardized warning system for a police vehicle fleet, there remains one large variable to contend with. How do you ensure the officer end-user operates that equipment in the manner best for a given situation? And how do you do it in a way that reduces their need to make constant decisions?

As an upfitter, I have struggled to balance ease-of-use with capability. As an officer, I have seen how warning systems can both help and hinder in the performance of my duties. As a supervisor, I have seen that there is an obvious need to standardize how and when we use the different features of our warning systems and the pitfalls of complicated written policies. As a trainer, I have seen how difficult it is to impart the proper use of warning equipment to the average police officer. And, as a motorist sharing the roads with emergency vehicles, I have experienced how poorly configured or selected warning equipment can be either overpowering or insufficient in its performance.

So the question is how can we achieve balance between what an emergency vehicle warning system can do and when it should do it?  The answer may very well lie with the new CanTrol WC™ Light and Siren system from Whelen®. CanTrol WC provides a level of vehicle and warning equipment integration never before available. 

In general terms, CanTrol WC makes logic-based decisions using vehicle and environmental inputs and then automatically configures the warning system according to pre-programmed parameters. CanTrol WC reduces and limits the officer’s need to interact with the warning system. This means less decision-making, better focus on their surroundings, and more appropriate lighting for the task at hand, all of which increases officer safety.

The current CanTrol WC system traces its roots to a project Whelen completed for the California Highway Patrol and builds on Whelen’s original B-Link™ and current state-of-the-art serial control and WeCan® systems. CanTrol WC replaces the warning system’s siren and light controller and consists of an Amplifier / Control Module and a remote Control Head. 

It controls all other warning components, including siren speakers, lightbars, arrow sticks, perimeter lighting, scene lighting, low frequency sirens, and so forth. CanTrol WC can also control vehicle lamps, interior lighting, gun locks, video & radar systems, K-9 system components, alarms…just about anything you can install, can be “CanTrol’ed.”

CanTrol WC becomes especially useful when you consider the number of mobile tactical problems officers can be faced with at any time, including traffic stops, felony stops, pursuits, emergency response, traffic control, scene illumination, crash investigation, disabled motorist assists, interdiction, high visibility traffic enforcement, roadside presence, escorts, crime deterrence, and others. 

Ideally, each of these mobile tactical problems requires officers to select different lighting and siren features and these choices are in turn limited by the capabilities of the warning systems. Until CanTrol WC, no existing warning system controllers provided the switching, external input & output flexibility, load management, and programmability necessary to allow the system to be specifically tailored to each of the above tasks.

Whelen’s advanced programming software allows the CanTrol WC system to be custom-configured to each end-user’s needs.  Using Windows® based “drag and drop” software, the administrator creates rules and prioritizes these rules using if / then logic. This creates tremendous flexibility and absolute consistency in how the emergency vehicle warning system operates. 

Not only is the system re-configurable as needs, vehicles and equipment change, it can be customized to specific inner-agency subunits and their unique roles and missions—patrol’s programming can differ from the traffic unit. A USB port on the amplifier / controller module makes transferring the programming easy.

CanTrol WC makes it possible to do the things many fleet managers and upfitters have thought would be ideal but until now were not possible. For example, warning lighting can be configured to automatically and variably dim according to ambient light, allowing the department to keep lighting output at the same relative brightness level in all conditions, versus blinding motorists at night. 

Additionally, you can configure the system to override ambient light settings based on vehicle speed, giving max output when needed for pursuit safety. You can also set specific flash patterns for nighttime or daytime use and, once again, you can program those to change based on vehicle speed. CanTrol WC even allows you to program siren tones to change automatically based on speed. And that’s just the beginning of its capabilities!

In pursuit mode, left and right turn signals can automatically activate the arrow pattern to match, giving trailing pursuit units better advance indication of your turning movements. Better still, the rear of the bar could dim while the front stayed full power to increase visibility for trailing units.  Or, the Howler™ low frequency siren can be activated automatically when the vehicle is in pursuit mode and the speed is below 50 mph and the brake pedal is activated, for example, eliminating the officer’s need to locate and press a button when they need to be observing the road. 

In the previous scenario, the programming has anticipated the intersection problem and configured an appropriate response. In addition to activating the Howler, the system could also change flash patterns and siren tones, flash headlamps and takedowns, or make other changes to make traversing an intersection safer.

By tying into the vehicle’s park circuit, you can design a mode for traffic stops that automatically transitions flash patterns and illuminated forward scene lights when the car is shifted into park.  If you are using one of Whelen’s superb multi-color DUO™ or TRIO™ LED bars, you could change colors or illuminate the entire bar as a take-down light! CanTrol WC can even dim or shut off particular light modules when a door is opened, preventing the officer from being temporarily blinded when exiting the car. You can even configure the system to activate rear scene lighting when the vehicle is placed into reverse.

Practically, the CanTrol WC system is only limited by your imagination. By assigning inputs and tying into the vehicle’s brake lights, turn signals, park lights, instrument lights, speed sense, park circuit, headlights, and horn, as well as adding an external temperature sensor and photo cell, you can program CanTrol WC to react appropriately to the environment and vehicle’s actions at any time. The operator simply selects a lighting mode using the slide switch, progressive buttons, or master on/off switch on one of the available control heads and CanTrol WC does the rest.

Part of CanTrol WC’s flexibility lies in the ability to program “states” for each switch. An example is that your takedown light switch could be programmed so one press activates only the lightbar’s dedicated takedowns, a second press activates the entire front of the bar in takedown mode (if using a DUO or TRIO bar), and a third press might give 360 degrees of light by illuminating the rear bar or work lights. 

Any control head button can be likewise configured, giving CanTrol WC more switching versatility than any other controller available. As any upfitter can attest, more often than not we run out of switches before we run out of things to switch, forcing us to limit features and reducing the warning system’s capabilities. CanTrol WC also allows for complete map-ability of control head buttons; put siren, lighting, accessory, and arrow buttons where you want.

CanTrol WC’s capability to control accessories is also unmatched by traditional warning system controllers. Gunlocks can be timed to remain open for up to 10 minutes or just momentarily open. If you desire a security lock feature, you can configure the system to use a two-button sequence or program it to monitor any other input or condition. 

Consider these examples: The gunlock can be design to unlock only when the car is in park, or when the brake pedal is pressed, or if you want to get sneaky, the rear defrost button could even be used to activate the lock. You could use CanTrol WC’s logic programming to automatically release the gunlock for the duration of a traffic stop. Simply tell it to open the lock when the car is in park and the lighting is in Mode 2, for example. The possibilities are limited only by your imagination and installation.

Since the CanTrol WC system has the ability to monitor ambient temperatures with Whelen’s optional CANTEMP sensor, it can be used to activate fans and drop windows as well as sound an alarm. This allows the system to protect K9 partners when left in hot vehicles and eliminates the need to install extra components. CanTrol WC could even be tied into a remote transmitter and used to activate door opening mechanisms. It is because of the unique nature of its analog (threshold) and logic input monitoring capabilities that CanTrol WC offers such amazing versatility. Not only can the system monitor ambient temperature and light but, by connecting CanTrol WC to your windshield wiper circuit, you can even tell the system if it’s raining!

Another benefit of CanTrol WC is that it can be used as a load management tool. CanTrol WC has the ability to sense even the smallest change in voltage using an integrated monitor. The system can be programmed to make a series of decisions based on voltage and prioritize what outputs are active accordingly. This built-in feature provides protection for the vehicle’s electrical system and ensures cranking ability is maintained. 

Officers can shut off and lock their cars while still having their warning systems active, allowing for significant fuel savings by reducing idle time. In addition to the voltage sensing ability, CanTrol WC can also be programmed for a timed shut-down delay of up to 60 minutes. Both these features help simplify the total vehicle installation by reducing the need to install separate timers and/or voltage monitors.

CanTrol WC’s ability to control your lighting is unmatched and lets your lighting system do more than ever before. Every light can be configured to flash in a synchronized pattern, either in phase or out of phase. This means any light, including the entire lightbar, can be set to flash in any of 161 patterns! Now you can use all your lighting to “communicate” the same message to others: faster patterns can be used when the vehicle is moving at high speeds, slower patterns for slower speeds, perhaps even steady-burn when stationary. This unique capability to vary flash rates and patterns based on vehicle speed is unique to CanTrol WC.

All this is done with just two wires and there is no longer a need to synch groups of individual light heads during the installation. Each light head is simply set to steady-burn and then wired to one of CanTrol WC’s numerous outputs. The time and cost of wiring multiple light heads is greatly reduced. You will also reduce the amount of expensive wiring you use and terminal connections that are made. Because all light heads are driven by the CanTrol WC system, their reliability increases and troubleshooting becomes easy. CanTrol WC also makes installing your WeCan-series lightbar faster than ever, plugging directly into the system via two communication wires.

CanTrol WC comes standard with 43 output connections to power all your lighting. Should more output connections be needed, optional 16-output remote expansion modules are available.  These expansion modules can be installed under the hood or anywhere else in the vehicle. Light heads are then wired to the expansion module, which communicates with the CanTrol WC unit via two communication circuits. 

CanTrol WC supports up to two additional expansion modules, allowing the system to operate up to 75 individual light heads, a traffic advisor, and a fully loaded WeCan-series lightbar. The remote expansion modules not only add capability to CanTrol WC, they provide installation flexibility as well. Mount them where you need to consolidate and simplify wiring. All front-end lighting can be wired to one, all rear lighting to another, for example.

Once everything is wired, the software interface is used to synch light heads, set or change patterns, and configure pattern changes based on selected modes or active inputs. You can also configure low power or cruise light modes for any connected light head. It is even possible to design and program a “test” mode in which all lights could activate in a full-power, steady-burn mode allowing for quick inspection. The CanTrol WC software has a virtual simulator feature that allows the programmer to preview how the entire lighting system will work and look, even mimicking the selected flash patterns. If you want to make changes, simply click the mouse.

The CanTrol WC system is even capable of making smart decisions to protect the officer from life-threatening mistakes and reduce department liability. CanTrol WC can automatically activate the siren, or even lights and siren when the vehicle is travelling at a high speed. Or, it can automatically re-activate the front lightbar if the officer forgets by sensing the car is no longer in park; with other systems, the officer would have to remember to manually turn off the front cut-off switch. 

If automatic switching isn’t desired, CanTrol WC could simply be programmed to emit a warning tone when it sensed a conflict, such as when the vehicle is exceeding a set speed without lights and siren or when front cut-off is active and the vehicle is moving.

Perhaps the smartest feature of CanTrol WC is that the vehicle operator can override it if so desired. For example, the officer may want to override the dimming feature of the lightbar for safety or other reasons. While CanTrol WC can be programmed to predict and anticipate lighting needs based on a set of parameters, there are always going to be unusual situations to contend with and this flexibility is built-in. The multiple options and versatility offered by the combination of automatic decisions and operator override means CanTrol WC can meet any challenge with unmatched safety.

Finally, CanTrol WC has complete Diagnostix™ capability built-in. Three banks of LED indicator lights monitor the lightbar, control head, and amplifier / controller module, allowing for rapid trouble-shooting. The system can indicate if a fused output has failed and also protects from over and under-voltage. In every way, CanTrol WC does more and does it better than any other system available.

Whelen makes the CanTrol WC system in its Connecticut and New Hampshire production facilities. The system meets or exceeds all applicable SAE, California Title XIII and NFPA requirements when properly configured and using matching Whelen lighting and siren components. It is backward and forward technology compatible, providing one solution for the entire fleet. Power and input / output cabling is provided with all necessary connectors. 

CanTrol WC provides for both hands-free and eyes-free activation of all major safety features and enables the emergency vehicle warning and lighting system to become a true safety tool for the officer. Advance pre-configuring of responses to mobile tactical problems—be they traffic stops, pursuits or crash scenes—reduces the officer’s need to make instantaneous decisions when timing and judgment are critical and distractions potentially lead to disastrous consequences.

Matthew Ayers is a Lieutenant with the Sevierville, Tenn. Police Department and the owner of Command & Control Installations (C2 Installs). He may be reached at or


CanTrol by the Numbers

  • 8 inputs for external triggers or switches
  • 8 programmable 10 amp outputs
  • 3 low-current trigger outputs
  • 32 dedicated 2.5 amp outputs standard
  • Up to 32 additional outputs available with optional remote expansion modules
  • 3 Diagnostix™ indicators
  • 5 different control heads to select from
  • Over 45 programmable siren tones
  • PA and radio re-broadcast included
  • 161 sychronizable flash patterns
  • Supports 1 or 2 siren speakers (100 watt)

Published in Police Fleet Manager, Jul/Aug 2012

Rating : Not Yet Rated

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