Crane operations are inherently high-risk — a jerky start under load, a brake that doesn't fully hold, or two hoists that drift out of alignment aren't just inefficiencies, they're the kind of small errors that can lead to catastrophic results.
Most of the mitigation for that risk traditionally sits outside the drive: mechanical interlocks, extra sensors, custom PLC logic built project by project. AT24 UB CraneSync moves a meaningful share of that safety and precision logic into the drive itself, with algorithms built specifically for hoist, trolley, and long-travel duty.
Conventional VFD integration for cranes often demands costly project-specific software development. CraneSync replaces that with integrated control algorithms for hoist, trolley, and long-travel — commissioned by parameter selection, not custom coding.
Three hardware lines, one control intelligence
CraneSync is software-defined crane intelligence, available on the hardware line that matches your installation environment — the same algorithms, in an enclosure rated for where the drive actually lives.
| Hardware line | Enclosure | Power range | Best fit |
|---|
| AT24 UB | IP20 | Full AT24 UB range | Cabinet-mounted crane panels, indoor installations |
| AT24 UB HP | IP55 | 18–400 kW | Crane control mounted directly on the structure, dusty/humid environments, no external cabinet |
| AT24 UB DM (Direct Mounting) | IP55 | 750 W–22 kW | Direct mounting on the motor or wall — vibration-resistant, no mounting cabinet or long motor/sensor cables needed |
Table 1. AT24 UB CraneSync hardware options.
Built for the moment a mistake gets expensive
The features below are grouped by what they protect: the mechanical brake and the load it's holding, the motion of the load in space, the drive's response to a sensor or component fault, and the precision of handling the load itself.
| Category | Function | What it does |
|---|
| Brake safety | Precise Brake Control | Pre-magnetizes the motor to generate full torque at zero speed before the brake releases, so the load never drops or jerks at the handoff; optional torque memory for reapplying the brake. |
| Brake safety | Anti-Slip Control | Monitors shaft rotation while the brake is applied; if the brake fails mechanically, the drive instantly restarts the motor to catch and hold the load. |
| Brake safety | Dynamic Braking | Dissipates braking energy in the motor windings via vector control, reducing reliance on the mechanical brake and extending its service life. |
| Motion safety | Anti-Sway Control | Dynamically adjusts the speed reference to cancel pendulum-effect load oscillation during travel and speed transitions. |
| Motion safety | Safe Speed Limiting | Restricts speed to a defined level in designated critical zones. |
| Motion safety | Slack Rope Prevention | Detects the exact moment a load touches ground and stops lowering instantly, keeping the rope tensioned and seated on the drum. |
| Fault tolerance | Sensorless Fallback | Switches instantly from closed-loop to open-loop (sensorless) control on encoder failure, without interrupting the operation. |
| Fault tolerance | Speed Deviation Monitoring | Compares actual speed/direction to setpoint continuously; closes the mechanical brake automatically if the deviation exceeds set limits. |
| Fault tolerance | Intelligent Derating | Automatically reduces performance under overheating to avoid an unplanned shutdown mid-operation. |
| Precision handling | Soft Lift | Detects load engagement in real time and optimizes speed to prevent snatch loading at lift-off. |
| Precision handling | Adaptive Hoist Speed | Automatically calculates optimal lift/lower speed from the current load — light loads and empty hooks move faster, heavy loads move at nominal speed. |
| Precision handling | Dynamic Current & Torque Limiting | Fast torque response eliminates mechanical stress from peak loads, sudden load changes, or aggressive ramping. |
Table 2. AT24 UB CraneSync safety and precision functions.
Removing the snatch-load spike
Soft Lift is worth a closer look on its own, because it addresses a failure mode that's easy to overlook until it's caused damage: the moment a slack hoist rope suddenly takes up a load.
Without any compensation, that instant produces a sharp force spike — a "snatch load" — well above the nominal weight, followed by a few seconds of mechanical ringing before it settles.
Soft Lift detects load engagement in real time and adjusts speed to prevent that spike from happening at all.
Coordinating more than one drive — without a separate PLC
High-capacity cranes routinely need multiple motors working in concert for hoisting or travel. CraneSync coordinates them directly, drive to drive, over a high-speed link:
- Master/Slave mode: high-speed drive-to-drive communication synchronizes multiple motors in either Speed-Torque or Speed-Speed mode, balancing load distribution across all of them.
- Position Synchronization mode: aligns the exact position of multiple hooks or travel wheels, maintaining level lifting of large loads and preventing mechanical stress during long-travel movement.
Both modes replace what would otherwise be external PLC-based coordination — simplifying the control architecture and removing an integration cost that would normally sit outside the drive.
Cabinet-level options for complete crane control
For projects specifying a full crane control cabinet rather than a standalone drive, AT24 UB HP cabinet designs can be built to individual specifications with input switch/contactor, brake chopper/resistor, DC/line/output chokes, EMC and sine filters, and — notably — an Active Front End (AFE) option.
AFE feeds braking energy back into the grid instead of dissipating it through braking resistors, cuts total harmonic distortion to under 5% (versus 30–50% on conventional drives), and keeps the motor at nominal supply voltage even when mains voltage sags.
Specifying drives for a new crane or retrofitting hoist controls on an existing one? Send us the mechanism (hoist, trolley, long-travel), motor count, and enclosure environment — we'll confirm the right CraneSync hardware line.
Request a datasheet or a configuration quote for AT24 UB CraneSync.
