An AGV or AMR that carries components from a receiving area on the ground floor to an assembly line upstairs needs more than a longer route. AGV elevator integration combines transport orders, lift calls, landing and door confirmation, safe boarding and alighting, and recovery after a fault. This guide helps a buyer in a Thai or ASEAN multi-floor factory specify the system in an RFP and verify it at FAT and SAT.
Define the boundary of responsibility first
The MES or WMS creates a transport request. Fleet control assigns a vehicle and route. A gateway or fleet controller connects to the lift interface. The lift manufacturer and maintainer remain responsible for the elevator equipment within their contractual scope. These are distinct roles. If the boundary is missing from the purchase specification, a vehicle stopped outside the door can become an unresolved dispute between the vehicle supplier, lift company and network team.
State the origin and completion point of the job, who provides each interface, the normal sequence, the safe response to an exception, the method for manual operation, and ownership of the event log. Before writing software requirements, observe actual trips, peak periods, loads, passengers, landing congestion and waiting locations on every floor. A lift is a shared resource. Fleet control cannot assume exclusive use merely because it has assigned a job.
What does “use the existing elevator” mean?
Record its model, controller, served floors, car dimensions, clear door width, rated load, floor threshold, door dwell behaviour, fire and power-failure operation and maintenance agreement. Compare those with the maximum external dimensions and mass of the loaded vehicle, including pallet or trolley overhang. Adequate rated load alone does not prove that a vehicle can turn in front of the car, cross its sill or carry an unstable stack. Determine whether the lift is for goods only or shared with passengers and whether robots may operate in the same car as people.
KONE describes a Service Robot API that supports lift calls and reports assigned lift status, floor, direction, door status and call status. Otis describes Integrated Dispatch as a cloud or on-premise API solution for service robots. Their public descriptions concern services such as deliveries, cleaning and building movement. They do not certify that a particular factory cargo lift, controller, load or site contract can use these functions. Ask the lift manufacturer about the exact equipment, interface entitlement, modification, local inspection and maintenance conditions. KONE Service Robot API; Otis Integrated Dispatch.
Specify the handshake from call to exit
Sending an AGV straight to the door as soon as MES requests an upstairs delivery is unsafe and operationally fragile. The door may be busy, and pedestrians or forklifts may cross its approach. Split a normal trip into: request accepted; vehicle reaches a safe waiting point; lift reserved or called; assigned car, landing and open door confirmed; landing and car occupancy checked; boarding authorised; vehicle stops inside and boarding is confirmed; destination call processed; destination landing and open door confirmed; exit authorised; vehicle leaves; car released; transport job closed. If a product does not expose one of these states, document a different verified way of reaching the same decision.
Bind requests and responses with a job ID, vehicle ID, car ID, source and destination, timestamps and timeout. Specify retries, duplicate suppression and what happens if an old response arrives after a timeout. After controller restart, read the current physical state before resuming. A single “door open” bit does not prove which car is present, whether it is level with the landing, whether the car has space, or whether entry is authorised.
Do not mistake an API status for a safety function
An API door or floor event can coordinate traffic. Whether it can perform a safety-related function is a separate engineering question. Assess delay, dropped messages, reconnection, false identity and power loss. ISO 3691-4:2023 specifies safety requirements and verification for driverless industrial trucks and systems, including AGVs and AMRs in its examples. ISO 12100:2010 provides principles for machinery risk assessment and reduction. ISO 13849-1:2023 addresses the design and integration of safety-related control-system parts. None means “connect an API and the installation is compliant.” Apply the relevant standards and local lift requirements to the real hazards and functions. ISO 3691-4:2023; ISO 12100:2010; ISO 13849-1:2023.
Measure vehicle, lift and building together
A catalogue vehicle width and turning radius cannot establish boarding clearance. Measure maximum load envelope, centre of gravity and movement, height clearance, landing-to-car level difference, car floor movement, stop-position variation, clear doorway, and final parking position inside the car. Test at least empty, maximum-load and uneven-load conditions. Consider wheel wear and surface slip in the positioning allowance. At the sill, check how the vehicle’s scanners perceive gaps and reflective surfaces. The load’s overhang may be more important than the vehicle body. A small angular positioning error can consume much of the apparent doorway clearance.
Provide a safe waiting point at every floor, a pedestrian route, a manual recovery path and emergency access. A waiting robot must not block fire doors, exits or forklift crossings. If an out-of-service lift causes a queue of vehicles, place a buffer well back from the landing and regulate entry from fleet control. Multi-floor transport is as much a shared-resource queueing problem as a route problem. Do not copy a generic clearance or door dwell time into an RFP: the acceptance value must come from the selected lift, load, vehicle and risk assessment.
Estimate capacity from the full trip cycle
Break each trip into travel to wait point, call wait, boarding, vertical travel, alighting, delivery and return or next job. Measure every important floor pair. For a car shared with passengers or another operation, specify a peak-period waiting-time percentile as well as the average. For illustration only, 20 requested trips per hour cannot be handled by a single path that completes only 12 trips per hour at a measured five-minute cycle. This hypothetical arithmetic is not a performance claim about any lift. Adding a second AGV does not double throughput if the lift is the bottleneck. The RFP should specify the number of jobs completed during a defined busy period under actual mixed use.
Separate the three interfaces
The business layer carries item, lot, quantity, origin, destination, priority and completion between MES/WMS/ERP and the transport system. The fleet layer selects vehicles and routes. The lift layer handles calls, assignment, car position, door state, occupancy and faults. Calling all three “API integration” hides who owns a fault at their boundary.
VDA 5050 standardises communication between mobile robots and fleet control. The jointly developed v3.0, announced in 2026, adds concepts for freer navigation, zones and path sharing. It is not a universal elevator-control protocol. A site using VDA 5050 still needs a defined lift interface, gateway and safety arrangements. Specify supported versions, required messages, proprietary extensions and disconnect behaviour for each proposed fleet and vehicle. VDA announcement; official specification.
API or approved physical interface?
Where an existing lift offers an authorised API, confirm exactly which calls and status data the equipment can provide. If it does not, ask the manufacturer and maintainer whether an approved external signal interface is possible. Do not independently wire the controller or attach a mechanical button pusher without assessing safety, contract, modification approval and local inspection. The network design must also state who detects a fault, who restores operation, and who confirms that it is safe to restart.
KONE’s public material describes WebSocket communication and call states including Allocated, Arriving, Served and Canceled. Those make a useful example of a state model; they do not mean every lift brand exposes identical data. Otis describes cloud or on-premise deployment and a simulation environment for robot developers. Check availability for the precise site and contract. KONE; Otis.
Assess hazards beyond the door
Review the approach, sill, car, exit landing and manual recovery route. Hazards include a pedestrian between vehicle and door, a protruding pallet, a wheel caught at a level mismatch, an AGV stationary in the car as doors close, and lift fire or power-failure operation. Include cleaning, maintenance, manual movement and fault recovery, not just automated production. Candidate measures include occupancy confirmation, controlled approach speed, obstacle detection, an exclusion line, inhibited entry while doors close, safe stop, controlled restart rights and local indication. Assign every measure to an owner and verify its performance. The presence of a sensor alone is not proof of adequate risk reduction.
If passengers may enter the same car, assess time separation, a dedicated car, occupancy detection, staff authorisation or other site-specific controls. Lift specifications, maintenance conditions and law decide which options are permissible. AGV requests must not override emergency, fire or maintenance modes. Evaluate the combined boundary between vehicle, lift and integration system, rather than accepting each supplier’s component test as a complete site assessment. ISO 3691-4:2023.
Write fault recovery before approving the normal demo
The RFP should include rejected calls, cancellation after assignment, a door that fails to open, wrong-floor information, failed boarding, a vehicle stuck inside, blocked exit, network outage, loss of power, emergency stop, fire operation and maintenance lockout. For each case, state safe stopping place, timeout, alert recipient, whether automatic retry is allowed, who may recover manually, and whether the business job is open or complete.
Consider a lost connection just after “door open.” The correct next step depends on whether the vehicle remains at the landing, crosses the threshold or is inside the car. On reconnection, do not reuse the old event as current permission. Read the current car position, door and vehicle location; if inconsistent, stop and hand control to a trained operator. Agree when the lift returns to normal dispatch so that unrelated calls cannot proceed with an AGV stranded inside.
Logs support both recovery and improvement
Use a common time basis and record order, reservation, car assignment, door event, vehicle position, boarding, exit, fault and operator action. Define access and retention for any personal information. Logs distinguish lift wait from blocked approaches and inaccurate vehicle positioning. The local HMI should clearly separate “vehicle stopped,” “waiting for lift” and “manual recovery required.” Provide job IDs that join MES/WMS events to fleet and gateway logs.
A compact RFP checklist
| Scope | Evidence to request | Acceptance example |
|---|---|---|
| Lift equipment | Car model, controller, served floors, approval | Manufacturer’s response and site verification |
| Load | Maximum envelope, mass, centre of gravity | Loaded threshold crossing |
| Transport order | Start, completion, priority, peak trips | Traceable MES/WMS-to-delivery record |
| Interface | Messages, identity, authentication, timeout | Duplicate, delay, disconnect, restart tests |
| Safety | Hazards at all floors, car and recovery | Stop, inhibited entry, supervised retrieval |
| Capacity | Peak completion and waiting target | Measurement with passengers and other work |
| Maintenance | Contacts and responsibilities | Fault isolation, logs and recovery time |
Agree numerical acceptance criteria after the site survey. A quote saying only “elevator compatible” is incomplete: ask which car and controller, what modification and contract costs are included, what the site tests cover and who handles an outage. Compare total cost across the same scope: vehicles, fleet software, lift interface, modification, network, sensors, floor and sill work, risk assessment, FAT/SAT, training and maintenance. A spare robot cannot remove a lift as a single point of failure. Include manual backup and the cost of interrupted production.
Evidence to gather before issuing the RFP
Photograph each landing and sill with a consistent measurement method. Map vehicle wait lines, pedestrian crossings, forklift routes and emergency access. Record the maximum loaded envelope, not just the dimensions of an empty cart. Label measured values separately from design assumptions, with dates and drawing revisions. Ask the lift operator about current call priority, goods-moving periods, planned service, fire and power-failure modes, and availability of support at night. Take a baseline of manual transport: trip time, lift wait, transfers, congestion, damage, wrong deliveries and interruptions. Use the same job definition after automation so performance can actually be compared.
FAT tests the logic; SAT tests the site
At FAT, use real equipment or a simulator to check the state machine and exceptions. Inject duplicate job IDs, delayed messages, cancelled calls, wrong-floor events, loss of connectivity and application restarts. Confirm that no double booking or false entry permission results. Otis advertises an online simulation environment for service-robot developers; confirm whether the chosen product and contract can use it. Otis.
At SAT, test actual doors, sills, floor finish, wireless coverage, passengers and normal lift usage. Include empty, maximum and uneven loads; each required car and floor; busy periods; manual interruption; emergency stop; maintenance mode; and recovery after power loss. A valid FAT API response does not prove that a loaded vehicle safely crossed the real sill. Record failure frequency, cause, recovery time and manual interventions as well as completed trips. Agree test count and pass criteria with all relevant suppliers before arrival on site.
Start production with one car, one floor pair, a limited load and a restricted period, then widen the scope after reviewing evidence. Train staff to return to manual transport. Decide which system retains unfinished jobs during a fallback so MES/WMS does not issue duplicate work.
Questions buyers ask
Can AGVs and AMRs use the same lift integration?
They can share the business request to call a lift, but positioning, approach speed, rerouting, obstacle handling and recovery differ by vehicle. VDA 5050 between fleet and vehicle does not automatically standardise the lift interface. Test each proposed vehicle with the physical doorway and fault scenarios.
Can an existing freight lift accept an API?
It depends on model, controller, contract and maintenance arrangements. A public service-robot API page is not proof of applicability to a factory goods lift. Give the lift provider equipment identifiers and request a written response on available interfaces, modification, inspection and cost.
What does AGV elevator integration cost?
There is no useful universal price without the equipment and scope. Compare vehicle and fleet cost alongside lift interface or approved contacts, gateway, landing changes, safety measures, software, site testing and recurring contracts. Send floor count, lift model, load envelope, required trips and operating hours with the enquiry.
Can an AGV ride with passengers?
That cannot be assumed. Evaluate occupancy, passenger flow, permitted lift operation, local rules, emergency modes and human intervention with the lift provider and safety team. Include the chosen operating method in SAT.
Conclusion
Treat the elevator as a shared machine with reservation, boarding, safety, fault recovery and maintenance responsibilities. Confirm equipment compatibility and ownership first; write the entire call-to-exit handshake; measure the real load and peak wait; and test software at FAT and the site at SAT. VDA 5050 addresses the fleet-to-vehicle link, while a lift vendor’s API applies only to equipment and functions the vendor confirms.
For route, floor and stopping-accuracy decisions, see our AGV layout design guide. For a related transfer boundary, see our conveyor-to-AMR integration guide. If you are still defining the floor pairs and loads, you can contact TOMAS TECH with the lift details and process map to discuss the integration scope.
Sources
- ISO, ISO 3691-4:2023, https://www.iso.org/standard/83545.html
- ISO, ISO 12100:2010, https://www.iso.org/standard/51528.html
- ISO, ISO 13849-1:2023, https://www.iso.org/standard/73481.html
- VDA, VDA 5050 v3.0 announcement, https://www.vda.de/en/press/press-releases/2026/260421_PM_VDA_5050_EN
- VDA/VDMA, VDA 5050 specification, https://github.com/VDA5050/VDA5050/blob/main/VDA5050_EN.md
- KONE, Service Robot API, https://dev.kone.com/api-portal/service-robot-api
- Otis, Integrated Dispatch, https://www.otis.com/en/us/products-services/products/otis-integrated-dispatch
