Servo Control System Medium Duty
Single Axis Azimuth Servo Pedestal with Indoor/Outdoor Architecture for 60 kg Payload Applications
The Servo Control System Medium Duty is a single axis azimuth servo positioner designed to mount and rotate payloads up to 60 kg with a windage area up to 1 sq mtr, supporting both continuous and non-continuous rotational motion across the full 360 degrees. The system splits into two electrically interfaced components: an outdoor Servo Positioner Unit that carries and drives the payload in the field, and an indoor Servo Control Unit that houses the drive electronics in a protected, rack mountable enclosure. Controlled over an Ethernet host interface with layered software, electrical and mechanical position limits, it is built for radar, antenna and surveillance pointing applications where reliable azimuth drive is the primary requirement.
What is the Servo Control System Medium Duty?
The Servo Control System Medium Duty functions as a mounting platform and drive mechanism for payloads up to 60 kg, providing continuous or non-continuous rotational motion of ±360° in the azimuth axis. It consists of a Servo Control Unit and a Servo Positioner Unit, electrically interfaced to operate as a single system. The Servo Control Unit governs the movement of the Servo Positioner Unit, a single axis pedestal with integrated drive electronics. The Servo Positioner Unit is designed for mounting in an open outdoor environment, while the Servo Control Unit is mountable in a standard 19 inch rack and located in a protected indoor environment.
| Parameter | Specification |
|---|---|
| Type of Pedestal | Single Axis Pedestal |
| Drive Configuration | Azimuth Only (Continuous or Non-Continuous) |
| Payload Weight | 60 kg (max) |
| Windage Area of Antenna | 1 sq mtr (max) |
| Top Plate Rotating Speed | 2 RPM (12°/sec) |
| Spatial Coverage | 360° (±180°) |
| Software Limits | ±180° |
| Electrical Limits | 5° away from software limits |
| Mechanical Limits | 10° away from software limits |
| Software Position Resolution | 0.1° |
| Position Accuracy | Less than 1° |
| Host Interface | Ethernet (LAN) Communication |
| Modes of Operation | Position, Inching and Velocity Modes |
| Wind Speed – Operational | 90 kmph |
| Wind Speed – Storage | 150 kmph |
| Operational Voltage | +24 VDC and +48 VDC |
| Weight | Less than 22 kg |
| Base Diameter | 350 mm (max) |
| Height | 300 mm (max) |
Indoor and Outdoor Split Architecture
Field deployed servo systems face a fundamental conflict: the drive electronics need protection from weather and temperature extremes, but the mechanical positioner has to be outdoors near the payload it drives. Rather than building a single weatherproofed enclosure that compromises on both fronts, the Servo Control System separates the two functions entirely. The Servo Positioner Unit, a ruggedized outdoor pedestal, handles the mechanical rotation and lives in the field environment. The Servo Control Unit, housing the sensitive drive electronics, sits in a standard 19 inch rack inside a shelter, vehicle cabin or protected enclosure. This means the electronics most vulnerable to moisture and dust ingress are never exposed to it, while the mechanical unit that must be outdoors is purpose built to handle that exposure.
Three Operating Modes Matched to Three Different Tasks
Position mode commands the pedestal to a specific azimuth angle and holds it there, used for pointing a sensor or antenna at a fixed bearing. Inching mode allows small incremental movements, intended for fine manual adjustment during alignment or calibration where a full position command would overshoot the target by a wide margin. Velocity mode commands a continuous rotational speed rather than a destination, used when the payload needs to sweep through a scanning pattern rather than settle on a point. Having all three available on the same controller means the system supports fixed pointing, manual fine tuning and continuous scanning operations without needing separate hardware for each task.
Three Independent Layers of Position Limiting
Position limits on this system are not a single stop point but three separate, independent layers. The software limit at ±180° governs normal operation under control system logic. Five degrees beyond that, an electrical limit removes drive power independently of the software, acting even if the control logic itself has faulted. A further ten degrees beyond that, a mechanical limit physically blocks rotation regardless of what the electronics are doing. Because each layer operates independently of the one before it, no single failure point, whether a software bug, a sensor fault or an electrical fault, can result in unconstrained mechanical travel. This kind of defense in depth matters specifically in unattended or remotely operated deployments where there may be no operator present to intervene if a single safeguard fails.
Continuous Rotation Without Cable Wind-Up Limitations
A pedestal that can only rotate within a bounded angular range before reversing has a structural limitation: cabling between the rotating top plate and the stationary base has to flex back and forth rather than spin freely. The Servo Control System supports true continuous rotation in azimuth, meaning the top plate can keep turning in one direction indefinitely rather than being forced to reverse at a travel limit. This is the operating mode radar antennas typically need for continuous 360° scanning, and the system also supports non-continuous operation for applications like fixed-sector surveillance, giving the same platform flexibility across both operational profiles.
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The outdoor unit needs to be close to the payload in a field environment, while the indoor unit's drive electronics benefit from a protected, temperature stable space. Splitting the system this way keeps the more sensitive electronics out of weather exposure entirely, while the mechanical positioner that must be outdoors is specifically built to handle field conditions.
It is a layered safety design rather than a single stopping mechanism. Software limits handle normal operation, electrical limits act as an independent backup a few degrees beyond that, and mechanical limits provide a final physical stop further still. Each layer works independently, so a single failure point cannot result in unconstrained mechanical travel.
Position mode moves to and holds a specific angle. Inching mode allows small incremental step movements for fine manual adjustment. Velocity mode commands a continuous rotational speed rather than a destination angle, used for scanning operations where the payload sweeps continuously.
Continuous rotation lets the pedestal keep turning in one direction without reversing, which radar antennas typically need for repeated 360° scanning. Non-continuous rotation suits applications where the target stays within a known angular window, such as fixed-sector surveillance. This system supports both.
It allows the Servo Control Unit to be commanded and monitored over standard network infrastructure rather than dedicated point to point cabling, making it straightforward to integrate into a networked command and control setup alongside other sensors on the same network.
With a 60 kg payload rating and 1 sq mtr maximum windage area, it suits medium class antennas, EO/IR packages and radar feed assemblies where azimuth-only drive is sufficient and elevation control is not required.
