Scroll chart: what it is, how it works and types of classification

Article updated: 07-01-2026

As the years go by, relays in analog panels lose insulation and welds in digital panels degrade due to the temperature and humidity of the gap. This causes random failures: the elevator stops between floors for no apparent reason, the doors do not open the first time, or it ignores calls intermittently. When the technician comes, the elevator works fine again because the failure is sporadic. If your elevator begins to suffer these «ghost breakdowns» repeatedly, the brain of the installation is exhausted.

What is an elevator control panel

In short, the control panel is not just another electrical component; It is the key piece that guarantees that daily trips in your building are fast, efficient and, above all, completely safe.

Janovsky, L. (1999). Elevator Mechanical Design (3rd ed.). Elevator World. 401-page reference work published by Elevator World, written by Professor Lubomir Janovsky of the Technical University of Prague. Available for purchase at: Elevator Mechanical Design (3rd ed.) — Elevator Books and on Amazon: Elevator Mechanical Design — AmazonElevator Books

• Control the opening and closing of automatic doors in a coordinated manner.
• Manage movement, the direction of travel and changes in speed of the cabin.
• Constantly monitor the status of security components and stop the equipment in the event of any anomaly.
• Record and order user calls to optimize routes.
  

Without this element, the elevator would be unable to interpret user orders and ensure that each trip is carried out safely.

Type of control panel

Disadvantages: Lacking digital diagnostic screens, the locating a fault requires the intervention of a qualified technician check the circuit control points. Although the review process is more manual, it offers the advantage of being a purely electrical and predictable system.

Classification of elevator control panels

Every time a user presses a button in the aisle or inside the cabin, that information does not go directly to the engine or doors. The signal travels directly to the control panel. It processes the order, checks that all security systems are closed and executes the corresponding action. Among its main functions the following stand out:

At a general level and without going into details, we can classify types of maneuver taking into account two aspects:

Maneuver according to the number of elevators that govern the control panel

• He maneuvering panel it is the element that control all the actions performed by the elevator: door opening, movements, operating states, speeds, etc., you could say that it is the I celebrate the installation.
• Safety in the vertical transportation sector is extremely strict. In 2017, European regulations came into force definitively EN 81-20 (next to EN 81-50), which replaced the old elevator design rules. This standard introduced drastic changes that directly affect the design and functions of the control panel in newly installed devices or in major modernizations.
• Miravete, A., & Larrodé, E. Elevators: Principles and innovations. Reverté Editorial / University of Zaragoza. File in the publisher: Elevators: Principles and innovations — Reverté EditorialRevert

As registration and call answering are carried out

The way the «brain» processes user commands determines the agility of the service. There are three main logics:

• The elevator is one of the most complex and expensive elements of any building. When we think about it, we usually visualize the cabin, the cables or the engine at the top. However, there is a hidden component in the hole or machine room that completely determines its operation.
  In this article we explain in a simple way what a control panel is, how to classify it, what differences exist between ancient and modern technologies, and what legal obligations its maintenance implies according to current regulations.
• Collective Maneuver on Descent: It is the standard in the vast majority of residential buildings in spain. This system does have memory to record multiple calls at the same time. If the elevator goes up to the 6th floor and a neighbor on the 3rd floor presses the button to go down, the box memorizes the order. First it will leave the passenger on the 6th floor and, during the journey down to the ground floor, it will automatically stop to pick up the neighbor on the 3rd floor. It is designed this way because in residential buildings the main traffic consists of leaving the floors towards the street.
• Collective Maneuver on Descent: It is the standard in the vast majority of residential buildings in spain. This system does have memory to record multiple calls at the same time. If the elevator goes up to the 6th floor and a neighbor on the 3rd floor presses the button to go down, the box memorizes the order. First it will leave the passenger on the 6th floor and, during the journey down to the ground floor, it will automatically stop to pick up the neighbor on the 3rd floor. It is designed this way because in residential buildings the main traffic consists of leaving the floors towards the street.

Differences between an analog panel and a digital panel: two generations of technology

Triplex or Multiplex maneuver: It follows the same intelligent principle of the duplex system, but coordinating the work of three or more cabins simultaneously. It is the standard in large stores and business centers.

The analog panel (Electromechanical)

The maneuvering box is not eternal. Changing this component is usually one of the most important reforms that a community of owners faces. You should not wait for the painting to «burn out» or become completely unusable; there are three critical signs which indicate that the time has come for its renewal:

• Advantages: Son robust and very durable systems against electrical voltage increases.
• This technology dominated the market during the 20th century. These paintings they do not have microprocessors or electronic boards advanced; They work through a complex network of cables, physical relays and mechanical contactors. Every time the elevator performs an action, a characteristic metallic «clack» is heard inside the engine room.

The digital box (Electronic)

Technological evolution has completely transformed the innards of elevators. Today two radically different types of paintings coexist in buildings: electromechanical (analog) and electronic (digital).

• Universal Maneuver: It's the most basic and oldest technology. The painting alone is able to process one order at a time. If a user enters the cabin and presses the 4th floor, the elevator will completely ignore any calls made by other neighbors from the hallways until their entire journey has ended. Its performance is very low, so today it is relegated almost exclusively to forklift or domestic lifting platforms with very few stops.
• Disadvantages: Son components more sensitive to electrical storms or sudden power outages, requiring additional electronic protections at installation.

When should the control panel be replaced?

Not all buildings they have the same human trafficking needs. A three-story housing block does not require the same movement management as a hospital or office skyscraper. For this reason, the tables are classified under two main criteria: the number of booths they control and the logic they use to answer calls.

Obsolescence and lack of original spare parts

If the building decides improve comfort by eliminating sudden jerks when starting and braking, it is mandatory to replace the box. In electric elevators, this involves installing modern motors with a frequency converter. In the case of hydraulic elevators, the improvement involves replacing the old mechanical plant with an electronic valve block.
Old frames are not prepared to communicate with this modern electronics or to manage the precise regulation of oil flow or new engine frequencies.

Multiplication of «phantom faults»

Collective Up and Down Maneuver (Selective): It is used in places like hotels, hospitals u offices, where the movements between intermediate floors are constant. In the hallways there is not a single button, but two (one up arrow and one down arrow). The user must indicate where they are going before going up. The frame is so intelligent that it will only stop the cabin if the direction of the passenger in the aisle coincides with the gear already in the elevator, optimizing the journeys to the maximum

Modernization of the tractor group (Engine)

Advantages: The diagnosis is immediate. These panels incorporate an LCD screen or a connection system for the technician's console. If the elevator fails, the box displays an exact error code (for example: «Error 04: Failure in the security contact of the door on floor 2«). The repair goes from taking hours to being resolved in a few minutes. Plus, they're much quieter, consume less power, and allow you to update your software to add new travel features.

The EN 81-20 regulation applied to the control panel

Improved automatic rescue systems: The regulations require that the panels manage emergency situations due to power outages much more efficiently. The frame must be connected to battery systems that ensure that the cabin lighting, ventilation and two-way rescue telephone system remain active and operational for a guaranteed minimum time to evacuate or communicate with trapped passengers.

The most important requirements that the team must manage under these regulations are:

• Ministry of Industry, Commerce and Tourism. Royal Decree 355/2024, of April 2, ITC AEM 1 «Elevators». BOE. Consolidated text in BOE (BOE-A-2024-7258), effective July 1, 2024: RD 355/2024 — ITC AEM 1 Elevators (BOE)Book HouseCEN. EN 81-50: Rules for the examinations, calculations and tests of lift components. Official file in AENOR store (payment rule): UNE-EN 81-50:2020 — AENOR Store
• Electronic component manufacturers constantly update their catalogs. When an old digital frame or a specific analog model turns more than 20 or 25 years old, factories stop producing their plates and components. If one of these critical plates breaks down and there is no stock on the market, the elevator can be stopped indefinitely for months while a second-hand compatible replacement is sought or an attempt is made to repair the damaged electronic track in an artisanal way.
• Protection system against uncontrolled movement of the cabin (UCMP): The the control panel must constantly monitor that the cabin does not move even a millimeter if the doors are open (for example, due to an engine brake failure). If it detects unauthorized movement, the panel immediately cuts off the power and activates an independent mechanical locking system to prevent serious accidents to users entering or leaving.

AENOR. UNE-EN 81-20: Safety rules for the construction and installation of elevators. Part 20: Elevators for people and people and loads. Official file in AENOR store (payment rule): UNE-EN 81-20:2020 — AENOR Store

Literature

• They exist on the market many switchboard manufacturers and many models of these. Each one has certain functions according to the client's requirements depending on where install a hydraulic elevator.
• Simplex maneuver: It's him most common system in residential buildings small or medium. In this case, the control panel governs a single cabin independently. It does not communicate with any other elevator.
• Duplex maneuver: Used in buildings that have two elevators located next to each other. A single centralized system controls both devices. When a user presses the aisle button, the box calculates which of the two cabins is closer or free, sending only one of them. This prevents both elevators from responding to the same call, saving waiting time and electrical energy.ç
• Supervision of electric bridges in the safety circuit: During the work de maintenance, technicians sometimes need to perform temporary «bridges» on the electrical contacts to locate a fault. The EN 81-20 standard requires the panel to automatically detect if a technician has forgotten a bridge placed by mistake at the end of the inspection. If the bridge is still in place, the frame blocks the elevator and prevents it from returning to normal service with users inside.