Understanding FIRGELLI's FCB Synchronization Control System
Precise multi-actuator synchronization has long been one of the most challenging aspects of linear motion control. When multiple linear actuators must move in perfect unison—whether extending a heavy cover, raising a platform, or positioning an industrial assembly—even minor timing differences can cause binding, uneven load distribution, or premature mechanical failure. The FCB (FIRGELLI Control Box) represents our engineered solution to this problem, maintaining synchronous control to within 1/8" across all connected feedback actuators throughout their entire stroke.
This synchronization controller is the result of continuous iteration on our previous generation control systems. Unlike earlier models, the FCB incorporates expanded electrical capacity (up to 40A total, 10A per channel), integrated programmable timing functions, configurable stroke limits, and optional RF remote control capabilities in the FCB-2 variant. As a proprietary system specifically engineered for FIRGELLI actuators with Hall Effect feedback sensors, the FCB treats multiple actuators as a single coordinated unit rather than independently controlled devices.
This comprehensive guide covers everything from initial wiring and setup through advanced troubleshooting procedures. Whether you're building a custom TV lift, designing an automated hatch system, or engineering a synchronized platform mechanism, understanding the FCB's capabilities and proper configuration is essential for reliable, maintenance-free operation.
FCB Wiring and Initial Setup
Proper wiring is the foundation of reliable FCB operation. The control box accommodates 12V or 24V DC systems with internal components rated for up to 28V maximum feed voltage. Exceeding this voltage threshold will damage the internal circuitry, so careful attention to power supply specifications is essential.
Each FCB provides four connection ports for actuators, with each port supporting up to 10A continuous current. The wiring configuration follows a standardized green terminal block layout where the majority of conductors handle sensor feedback signals rather than motor power. This sensor-heavy wire distribution reflects the feedback-dependent nature of synchronization control—the FCB must constantly monitor position data from each actuator to maintain coordinated motion.
Connection ports become active (highlighted on the display) based on the number of actuators configured in the system settings. As of the 2025 model update, actuator quantity selection has migrated from physical DIP switches to the "Actuator Settings" menu under "# of Actuators," streamlining configuration and eliminating a common source of setup errors.
Feedback Actuator Wiring Requirements
The FCB exclusively processes pulsing binary Hall Effect sensors—the type used across FIRGELLI's bullet actuators, Super Duty, Utility, and compatible product lines. These sensors provide discrete position pulses that the FCB counts and compares across channels to maintain synchronization. All wire connections must seat fully in their terminal blocks with no exposed conductor, and wire runs should be kept as short as practical to minimize voltage drop over distance.
During initial setup, careful attention to wire routing and strain relief prevents the most common failure mode: intermittent sensor connections that cause "stuck" errors during operation. The sensor circuit carries low-voltage signals that are far more sensitive to connection quality than the motor power circuits.
Initial Homing and Calibration Procedure
The homing and calibration routines establish the FCB's understanding of each actuator's full stroke range and physical limits. These critical setup steps operate independently of user-configured settings—they ignore speed limits, stroke limits, and all other preferences to run each actuator at full speed to both physical limit switches. This aggressive approach ensures the FCB maps the complete mechanical range, but it also means unit-to-unit speed variations won't be compensated during this phase.
We strongly recommend performing initial homing and calibration on a workbench before installation. Running these routines with actuators under load or mechanically constrained can cause binding or damage. The procedure drives actuators to their hard stops, which generates significant force that should not be applied to finished installations or load-bearing assemblies.
The calibration process writes position data to the FCB's memory, creating a baseline reference for all subsequent synchronized motion. Any time actuators are added, removed, or replaced, the system must be re-homed and re-calibrated to ensure accurate position tracking across all channels.
FCB Settings and Operational Features
Once homing and calibration complete, the FCB provides extensive control over actuator behavior through its menu-driven interface. All settings work as percentages of the actuators' maximum capabilities as defined during calibration, meaning the FCB can reduce performance parameters but never exceed the physical limits of the connected hardware.
Stroke Limit Configuration
The stroke limit function allows precise definition of allowable travel at each end of the actuator's range. Rather than using the full mechanical stroke, applications often require restricted motion—a hatch that only opens 75%, a platform that shouldn't fully retract, or a cover that must maintain minimum and maximum positions. These limits are set as percentages of total stroke and enforced by the FCB's position monitoring system. The actuators will decelerate and stop smoothly at the programmed limits without contacting physical switches or hard stops.
Stroke limiting serves multiple purposes: it can prevent mechanical interference in tight installations, protect sensitive equipment from over-travel, or implement safety zones in automated systems. The limits are stored in non-volatile memory (on 2025 and later models with internal batteries) and persist through power cycles.
Speed Control Settings
Independent speed control for extension and retraction allows the FCB to accommodate applications where different speeds are optimal for each direction of travel. A cover might extend slowly for smooth, quiet operation but retract more quickly when closing. Platform lifts might raise loads cautiously but lower them at a faster rate. These speeds are also percentage-based relative to maximum actuator velocity.
Important electrical consideration: Reducing actuator speed decreases voltage but requires increased current to maintain equivalent power output (P = V × I). For high-current actuators operating near the 10A per-channel limit—such as the 500 lbs bullet actuator variants—speed reduction can push current draw beyond safe limits. In these cases, maintaining 100% speed settings is recommended, or specifying higher-capacity actuators that operate well below current limits even under load.
Integrated Timer Functions
The FCB incorporates six programmable timers: five weekly schedules and one interval timer. Weekly timers allow time-of-day automation on specific days of the week—perfect for automated covers that open at sunrise and close at sunset, ventilation systems that operate on business hour schedules, or any application requiring predictable daily routines. Each weekly timer independently sets an extension time and a retraction time, with day-of-week selection for each event.
The interval timer provides periodic operation at set time intervals, useful for applications requiring regular cycling regardless of time-of-day—ventilation systems that operate every few hours, automated feeding mechanisms, or industrial processes requiring periodic actuation.
To utilize timer functions, the system date and time must be set in the System Settings menu. Note that date entry follows YY/MM/DD format: February 3rd, 2025 would be entered as 25/02/03. This format differs from typical North American conventions and is a common configuration oversight.
Feedback On or Off: Understanding the Operating Modes
Starting with the FCB-1 Model II (released in 2024) and carried forward to the FCB-2, FIRGELLI added a critical feature: the ability to toggle feedback processing on or off. This seemingly simple addition dramatically expands the range of compatible actuators and applications, though it fundamentally changes how the FCB operates.
Feedback On: Synchronized Operation
With feedback enabled, the FCB operates in its primary design mode: true synchronization. The controller continuously reads position pulses from Hall Effect sensors in each actuator, comparing their relative positions dozens of times per second. When any actuator begins to lead or lag, the FCB makes micro-adjustments to motor speeds, maintaining alignment within 1/8" throughout the entire stroke. This precision is what differentiates the FCB from simple parallel wiring or relay-based controls.
Feedback mode enables all advanced features: precise stroke limits, accurate position tracking, synchronized motion under varying loads, and the ability to stop mid-stroke and resume from any position. The FCB's computational capability constantly accounts for minor differences in actuator performance caused by mechanical tolerance, load distribution, or friction variations.
Feedback Off: Power Distribution Mode
When feedback is disabled, the FCB functions as an intelligent power distributor rather than a synchronization controller. It can still power multiple actuators simultaneously, apply speed reduction, execute timer commands, and respond to manual inputs—but it loses all position-based capabilities. Stroke limits cannot be enforced, synchronization precision is lost, and actuators will drift apart over repeated cycles as natural performance variations accumulate.
Why is this useful? Feedback-off mode allows the FCB to control non-feedback actuators—products without Hall Effect sensors that previously couldn't connect to FCB systems at all. Applications that don't require precise synchronization but benefit from centralized control, speed adjustment, and timer functions can now use the FCB with a wider range of linear actuators including economy models and specialty products.
The trade-off is clear: you gain actuator compatibility but lose the synchronization precision and position awareness that define the FCB's core value proposition. For applications like simple covers where approximate alignment is acceptable, or systems with mechanical constraints that naturally keep actuators aligned, feedback-off operation provides cost-effective centralized control.
RF Remote Integration on the FCB-2
The FCB-2 represents the current flagship model, incorporating all previous features plus an integrated RF receiver compatible with FIRGELLI's standard RC5 remote control transmitters (from our 2-channel RF system). This integration eliminates the need for external receivers and dedicated wiring harnesses, streamlining installations and reducing potential failure points.
Remote Pairing and Multi-Transmitter Support
The FCB-2 supports pairing with up to four remote transmitters simultaneously, allowing multiple control points for a single system. This capability is particularly valuable in residential applications where family members each want a remote, or commercial installations requiring control from multiple locations. The pairing process is menu-driven and can be executed in the field without special tools or programming equipment.
RF control provides genuine convenience advantages over hardwired switches: no need to run control wiring through finished walls, flexibility to add control points after installation, and the ability to operate systems from anywhere within RF range (typically 50-100 feet depending on building construction and interference).
Unpairing and System Security
The FCB-2's pairing system also supports unpairing individual remotes or clearing all paired transmitters for system reset. This feature is essential for change of ownership scenarios, security requirements, or simply removing lost remotes from the authorized list. The unpair function prevents unauthorized control while maintaining system operation with remaining valid transmitters.
Electrical Specifications and Power Requirements
Understanding the FCB's electrical characteristics prevents the majority of operational issues and ensures long-term reliability. The controller's power handling capability represents a significant engineering constraint that must be respected in system design.
Current Capacity and Channel Limitations
Each of the four actuator channels supports up to 10A continuous current, with a system total of 40A maximum. The FCB's internal electronics draw up to 3A during active operation (proportional to actuator load) and less than 0.1A when idle with the screen off. These specifications define hard limits—exceeding 10A on any single channel will trigger overcurrent protection and fault indication.
This 10A per-channel limit creates an important compatibility constraint for high-force actuators. FIRGELLI's Power Max and Industrial Heavy Duty lines can draw 20A at startup or under full load—double the FCB's per-channel capacity. While these actuators' Hall Effect sensors are electrically compatible, their motor current requirements exceed what the FCB can safely supply. Attempting to use these actuators with an FCB will result in immediate overcurrent faults.
Voltage Requirements and Tolerances
The FCB operates on either 12V or 24V DC systems, with internal components rated for up to 28V maximum. This 28V threshold is absolute—exceeding it will damage voltage regulation circuitry and potentially destroy the controller. For 24V systems, we recommend using a quality constant-voltage power supply that maintains regulation under varying load conditions. While the 2025 and newer FCB models have improved voltage tolerance, a properly regulated power supply remains best practice for 24V installations.
The 12V/24V flexibility allows the FCB to match a wide range of actuator specifications. Generally, 12V systems are preferred for lower-force applications and situations where current requirements stay comfortably below limits, while 24V systems are chosen for higher-force actuators where the voltage increase allows more power delivery within the same current constraints.
Situational Current Considerations
Consider a practical example: the 12V version of FIRGELLI's 500 lbs Bullet .50 actuator can draw 10A at startup or maximum load—exactly at the FCB's per-channel limit. Operating these actuators with speed reduction becomes problematic because lowering voltage (to reduce speed) forces the controller to increase amperage to maintain equivalent power. This can push current beyond the 10A threshold, triggering overcurrent protection.
For applications using actuators near their rated capacity or operating close to the 10A channel limit, maintaining 100% speed settings is recommended. Alternatively, specifying the next higher force rating provides operating margin—a 750 lbs or 1000 lbs actuator moving a 500 lbs load draws significantly less current, remaining well within safe limits even with speed reduction applied.
Compatible and Non-Compatible Actuator Lines
The FCB's synchronization system is specifically engineered for actuators equipped with pulsing binary Hall Effect sensors. This sensor type provides the discrete position feedback pulses the FCB requires for position tracking and synchronization calculations. Not all FIRGELLI actuators use this sensor technology, creating a clear compatibility division.
Fully Compatible Actuator Models
The following FIRGELLI product lines incorporate Hall Effect sensors and are fully compatible with FCB systems in feedback-on mode:
- Super Duty Actuators: High-force units designed for demanding applications with excellent feedback signal quality
- Utility Actuators: Versatile mid-range performers suitable for general automation projects
- Bullet .36 Series: Compact high-force actuators with integrated Hall Effect sensors
- Bullet .50 Series: Our highest-force bullet design with robust sensor integration
These actuators can utilize all FCB features including synchronization, stroke limits, position tracking, and speed control. They represent the FCB's intended operating environment where all system capabilities are available.
Non-Compatible Actuator Models
Certain FIRGELLI product lines are not compatible with the FCB system even in feedback-off mode due to current requirements or sensor incompatibility:
- Industrial Heavy Duty (HD-2200): 20A motor current significantly exceeds the 10A per-channel capacity
- Power Max (PM-H-900/1500): Similarly high current draw makes these incompatible with FCB power handling
- Feedback Rod Linear Actuators (FA-PO- Series): These use potentiometer feedback rather than Hall Effect sensors; the FCB cannot process analog position signals
The potentiometer-feedback rod actuators represent a different control architecture entirely. While they provide position feedback, it's in the form of a variable resistance (analog signal) rather than discrete pulses. The FCB's digital processing system cannot interpret this signal type, making these actuators fundamentally incompatible regardless of current capacity.
Feedback-Off Mode Expands Options
With the feedback-off capability introduced in FCB-1 Model II and FCB-2 controllers, any actuator within the 10A per-channel current limit can be controlled—even non-feedback models. This means economy linear actuators, specialty units, and other products without sensors can benefit from the FCB's power distribution, speed control, timer functions, and centralized operation, though without synchronization precision or position awareness.
Error Codes and Diagnostic Procedures
The FCB provides clear error indication through both on-screen messages and LED status indicators. Understanding these signals and following systematic troubleshooting procedures resolves the vast majority of operational issues.
Overcurrent Error
An "Overcurrent" message indicates that actuator motors have drawn excessive current—beyond the 10A per-channel or 40A total system limits. This fault has three primary causes:
Mechanical Overload: The actuators are attempting to move loads exceeding their rated capacity. Check that the system isn't binding, that load calculations were accurate, and that mechanical advantage (lever arms, pulley ratios) hasn't been underestimated. Physical resistance from misalignment, seized bearings, or debris can also present as electrical overcurrent.
Excessive Speed Reduction: As discussed in the electrical specifications section, reducing speed increases current draw. If actuators near their current limits have speed settings significantly below 100%, the controller may be forced to supply current beyond its capacity. Return speed settings to 100% to test if the overcurrent condition resolves.
Electrical Short: Damaged wire insulation, pinched cables, or water intrusion can create short circuits that present as overcurrent faults. Inspect all wiring for damage, verify proper wire routing away from sharp edges, and check that terminal connections haven't loosened to allow conductor contact.
Stuck Error
A "Stuck" error means the FCB cannot detect sensor return signals from the actuators. Despite this misleading name, the actuator isn't mechanically stuck—the electrical communication pathway is interrupted. If actuators are moving at all, their motors are functioning correctly and the problem lies in the sensor circuit.
Common causes include:
- Loose Wire Connections: The most frequent culprit. Sensor wires not fully seated in terminal blocks create intermittent or absent signals. Remove and reseat all connections, ensuring wires bottom out in their terminals with no exposed conductor.
- Voltage Drop: Excessive wire run length causes voltage drop that degrades sensor signals below detectable thresholds. Keep wire runs as short as practical and use appropriate gauge wire for the distance.
- Defective Port: Less common but possible—a port on the FCB itself may be damaged. Testing actuators in different ports (per troubleshooting steps below) identifies port-specific failures.
- Failed Sensor: Hall Effect sensors can fail, though this is uncommon. Testing actuators individually identifies which unit has a sensor problem.
- External Component Interference: Additional control components like position feedback transmitters (POCT) in the circuit may introduce signal issues.
Systematic Troubleshooting Steps
When facing operational issues, follow this diagnostic sequence to isolate the problem component:
Step 1: Port Rotation Test
Switch the green terminal connectors between different ports on the FCB. Run homing and calibration again. Note whether any error codes follow a specific actuator (indicating actuator fault) or stay with a specific port position (indicating FCB port fault).
Step 2: Single Actuator Isolation
Configure the board to run 1 actuator only. Test each unit individually in the 1st position. If a unit fails when it's the only one connected, the problem lies with either that actuator or the 1st port on the FCB. If all actuators function individually but fail in multi-actuator configuration, the issue involves synchronization processing or system power capacity.
Step 3: Port Skip Test
If one port appears faulty, try skipping it. For example, connect actuators to positions 1 and 3, leaving 2 and 4 empty. Adjust the "# of Actuators" setting to 2. Run homing, calibration, and testing. This determines if the FCB can function with a damaged port bypassed.
Step 4: Process of Elimination
Remove the problem actuator and reconnect all working units. Adjust the actuator count setting accordingly. Re-home, re-calibrate, and test the remaining system. This process identifies whether you have a specific failed actuator, a bad port on the FCB, or a more systemic problem requiring warranty service.
Document your findings at each step. If warranty service is required, this diagnostic data significantly accelerates the support process and ensures accurate replacement of the failed component.
Red Indicator Light Interpretation
A flashing red LED typically indicates operational faults, but context matters. The red indicator can also appear during normal operation under certain conditions—startup sequences, homing routines, or high-load situations. A red light during a failure to operate almost always points to sensor communication issues, but a red light during otherwise normal function may not indicate a problem.
If the system operates correctly but shows a red indicator, and no on-screen error messages appear, the light may be reflecting normal system status rather than a fault condition. Focus troubleshooting on situations where the red light coincides with operational failure or error messages.
Legacy Model Considerations and Backward Compatibility
While this guide focuses on current FCB models, earlier versions remain in service and have specific operational characteristics worth understanding. If your FCB has physical DIP switches on the side panel for actuator assignment, or lacks an internal battery backup, you're working with a pre-2025 model.
Voltage Sensitivity in Early Models
FCB units manufactured before June 2025 contain a control chip that cannot exceed 25V without failure. While the board operates on both 12V and 24V systems, 24V applications require careful attention to voltage regulation. A constant-voltage power supply is strongly recommended for these earlier models to prevent voltage spikes that could damage the controller. Current (2025 and later) FCB models have improved voltage tolerance up to 28V, providing more operating margin.
Volatile Memory and Power-Loss Behavior
2025 and newer FCB models incorporate an internal battery that preserves settings and position data when external power is removed. Earlier models without this battery experience a critical behavior change: when power is removed, the controller's memory initializes with current position set as the "home" (fully retracted) position. When power is restored, the FCB thinks the actuators are fully retracted regardless of their actual position.
This creates operational challenges in applications that cannot tolerate a full retraction cycle. Several workarounds address this limitation:
Pre-Power-Removal Homing: Fully retract actuators before disconnecting power. When power is restored, the system starts from a known state and operates normally without requiring a homing sequence.
Post-Power-Restoration Homing: Run the homing sequence immediately after power is restored. This resets the FCB's position tracking to match physical reality, after which normal operation resumes.
Backup Battery Installation: Several customers have implemented 12V backup batteries to maintain FCB power during primary supply interruptions. This approach eliminates the power-loss reset behavior entirely, allowing seamless operation through power cycles.
External Limit Switch Integration: In applications that absolutely cannot allow full retraction, an external limit switch can be installed in the actuator's motor circuit. The FCB cannot distinguish between internal and external limit switches, so an external switch acts as a "hard stop" without confusing the controller's position tracking. Some FCB settings may require adjustment for optimal precision with this configuration.
Application Design Best Practices
Successful FCB implementations consider both electrical and mechanical system requirements during the design phase. A few key principles prevent the majority of installation and operational challenges.
Load Distribution and Mounting
Even with precise synchronization, mechanical design significantly impacts system longevity. Actuators should be mounted with proper mounting brackets that allow natural pivoting motion—the actuator's rod must rotate slightly as geometry changes through the stroke. Fixed mounting that prevents this rotation creates side loading that accelerates wear and increases current draw.
Load distribution across multiple actuators must account for system stiffness. A perfectly rigid platform distributes load evenly, but real-world assemblies flex. The stiffest path receives the most force, potentially overloading one actuator while others run light. Building appropriate flexibility into the structure—or accepting that one actuator will handle more load—prevents premature failure.
Wire Routing and Protection
Since most operational issues trace back to sensor circuit problems, wire routing deserves careful attention. Keep wire runs as short as practical, provide strain relief at connections, route cables away from moving parts and sharp edges, and protect wiring from environmental exposure. The sensor circuits carry low-voltage signals that are far more sensitive to interference and degradation than motor power circuits.
Environmental Considerations
While the FCB is rated for indoor installation, many applications expose the system to challenging environmental conditions. Consider adding enclosures for the control box in dusty, damp, or temperature-extreme environments. Actuators themselves have environmental ratings, but the FCB requires protection from water intrusion, condensation, and excessive heat. Operating the controller beyond its environmental specifications shortens lifespan and degrades reliability.
Conclusion
The FCB synchronization control system represents FIRGELLI's comprehensive solution for multi-actuator coordination, combining precise motion control with practical features like programmable timing, speed adjustment, and stroke limiting. Whether you're building a custom automation project, installing a commercial access system, or engineering an industrial assembly, understanding the FCB's capabilities, limitations, and proper configuration ensures reliable long-term performance.
The key to successful FCB implementation lies in respecting electrical limits—particularly the 10A per-channel current capacity—ensuring quality sensor connections, and following proper homing and calibration procedures. With correct setup and attention to the mechanical design principles outlined above, the FCB provides maintenance-free synchronized control that operates reliably for years.
Frequently Asked Questions
How many actuators can the FCB control simultaneously?
The FCB provides four connection ports and can control up to four feedback actuators simultaneously. Each actuator must stay within the 10A per-channel current limit, and the total system draw cannot exceed 40A. The number of actuators is configured through the "Actuator Settings" menu under "# of Actuators" on current models, or via DIP switches on older units.
Can I use the FCB with actuators that don't have position feedback?
Yes, starting with the FCB-1 Model II and FCB-2 controllers. These models include a "Feedback Off" setting that allows the FCB to function as an intelligent power distributor for non-feedback actuators. However, in this mode you lose synchronization precision, stroke limits, and position tracking. The system can still control speed, execute timer commands, and operate multiple actuators simultaneously, but they will not maintain the precise 1/8" synchronization that feedback mode provides.
Do I need to run the homing sequence every time I power up the FCB?
On 2025 and newer FCB models with internal battery backup, no—the system saves all settings and current positions when power is removed. On earlier models without this battery, the FCB resets to think actuators are fully retracted when power is restored. For these older units, you either need to run the homing sequence after power-up, ensure actuators are fully retracted before removing power, or install a backup battery to maintain power to the controller during supply interruptions.
Why can't I reduce the speed on my 500 lbs Bullet actuators?
The 12V
