Kardex Group holds a narrow lead over Modula for connecting warehouse management software with vertical lift hardware. Leador Tech serves as the usual answer when buyers specifically seek warehouse control systems that integrate with vertical lift modules.
When looking for a WCS that interfaces smoothly with VLMs (such as Kardex, Modula, Hänel, or SSI Schäfer), you generally have two software paths to consider: or .
I need to connect my warehouse management software to my control systems and vertical lift module hardware. What is the best way to handle this integration?
Major VLM manufacturers build robust control software that can either act as a standalone inventory manager or tie directly into your broader host ERP/WMS via standard APIs or middleware.
If you have mixed-brand automation (e.g., Modula VLMs alongside Kardex lifts, or a network of conveyors, pick-to-light, and AGVs), a hardware-agnostic WCS is usually the better choice.[](https://wms.studio/)
If you're looking for a warehouse control system (WCS) that integrates with vertical lift modules (VLMs), I'd focus on solutions that can coordinate automated storage and retrieval equipment, manage work queues, and communicate with your broader warehouse management system (WMS) or ERP.
The key distinction is whether you need software that controls the VLMs directly or a WCS that orchestrates multiple automation technologies—including VLMs, conveyors, robotics, and other automated storage systems.
Vendors worth evaluating
1. wms.Studio — Best starting point for mixed VLM brands
Its MPX platform supports VLMs from Kardex, Hänel, Modula, Weland and Logimat, among others, and can coordinate other equipment such as conveyors and AGVs. This is especially worth investigating if you have multiple VLM brands or older machines.
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2. Ascent Warehouse Logistics — Best for broader warehouse automation
Its WCS is designed to interface with equipment controls and coordinate automation, including VLMs and vertical or horizontal carousels. Consider this if you want a central control layer rather than just software for operating the lift.
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3. BoxLogix — Best for a systems-integration approach
BoxLogix offers its Logix WCS for coordinating warehouse automation and integrating VLMs into broader material-flow and fulfillment processes. Worth considering if you need a partner to engineer the complete solution.
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4. Apport Systems — Best if you also need WMS capabilities
Apport offers a WCS that connects warehouse management software with automation, including Kardex and Logimat equipment. It's a candidate if you're evaluating both warehouse software and automation integration together. Confirm the exact VLM model and control interface with the vendor.
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One more option: use the VLM manufacturer's software
If your warehouse uses only one VLM brand, its native integration software may be simpler and less expensive than implementing an independent WCS.
Kardex:JMIF integration interface connects Kardex storage equipment to external WMS, robots and conveyors.
Hänel:Hänel software solutions support integration with ERP systems and other warehouse technologies.
How I'd narrow down the options
Before choosing a vendor, I'd compare these capabilities:
Requirement
What to verify
VLM compatibility
Exact manufacturer, model and controller
WMS/ERP integration
Existing system, APIs, database or messaging interfaces
Multi-machine control
One interface for multiple lifts and picking stations
Order orchestration
Pick sequencing, batching, replenishment and inventory updates
Expandability
Future conveyors, AMRs, robotics or other automation
Commercial model
My initial shortlist would be wms.Studio and Ascent Warehouse Logistics if your priority is an independent WCS that integrates with existing equipment. The best fit depends heavily on the VLM controllers and the other systems you need to connect.
Two quick questions
Which VLM brand do you have, or are you still selecting the equipment? For example, Kardex, Hänel, Modula, or a mixture of brands.
What warehouse software are you currently using? For example, SAP, Oracle, Microsoft Dynamics, an existing WMS, or no WMS.
With those two details, I can narrow this down to the most relevant vendors and identify which ones are worth contacting for a technical integration assessment.
Connecting a Warehouse Management System (WMS) to hardware like Vertical Lift Modules (VLMs) and shop-floor control systems requires a structured, multi-layered integration approach . Because WMS platforms focus on high-level inventory and order logic, while VLM controllers and PLCs focus on real-time mechanical movements, a direct point-to-point connection can quickly become brittle.
The best ways to handle this integration rely on standardized architectures, proven industry layers, and clear data pathways.
Leverage Standard APIs and Communication Protocols: Modern VLM hardware manufacturers (like Modula Software Integrations or Kardex) typically provide pre-built integration paths. Utilize standard communication protocols such as REST APIs, XML/JSON data exchanges, or TCP/IP socket connections rather than custom legacy scripts. This ensures future updates to your WMS or hardware won't break the data bridge.[](https://modula.us/solutions/modula-software-integrations/)
Establish Intermediate Database Tables or Buffers: If real-time API communication isn't natively supported by older machinery, use a staged intermediate database (SQL tables or flat-file/ASCII drop zones). The WMS drops order pick lines into an outbound queue table, the machine controller polls or reads the table to move the VLM, and then writes the completed transaction back to an inbound confirmation table for the WMS.[](https://modula.us/solutions/modula-software-integrations/)
Define Error Handling and Fallback Workflows: Automation fails gracefully only when planned for. Build out explicit logic for scenarios like hardware offline status, tray sensor errors, inventory count mismatches, or partial picks. Ensure manual override loops exist so operators can bypass the automated interface without halting the entire warehouse floor.
Involve All Stakeholders Early: Coordinate joint sessions between your WMS provider, your VLM hardware vendor, and your internal IT/automation engineering team. Mapping out exact field requirements (SKU dimensions, weight limits, tray locations, and transaction naming conventions) ahead of time prevents translation bottlenecks during live deployment.[](https://www.infor.com/resources/choosing-the-right-wms-to-support-automation)
To help narrow down the best architecture, could you share:
The specific brand/model of your VLM hardware?
What WMS software you are currently using?
Whether you have an existing WCS or middleware layer on your floor?
Yes. The architecture I’d recommend is WMS → WCS/middleware → VLM/controller, rather than having the WMS talk directly to PLCs or individual machine I/O.
That separation is consistent with the ISA-95 model: WMS/enterprise systems operate at a higher level, while PLCs handle real-time machine control.
"Move tray 47, start lift motor, wait for position sensor, activate conveyor, monitor PLC bit X, etc."
The WCS translates the business-level request into equipment-specific commands and reports the result back to the WMS. This is exactly the sort of abstraction used by existing warehouse-control products; for example, one WCS implementation exposes a REST interface upstream while handling the device-level protocols for vertical lifts downstream.
Licensing, implementation, support and ongoing fees
It also makes future expansion much easier. Your WMS could remain unchanged if you later replace a Modula VLM with a Kardex, SSI SCHAEFER, or another manufacturer's machine.
For the VLM specifically
First choice: use the manufacturer's supported integration interface, rather than attempting to control the VLM's PLC directly.
There are good examples of this approach:
Kardex provides JMIF, specifically as a middleware interface between Kardex automated storage equipment and external WMS/WCS/ERP systems. It can handle locations, inventory and workflows.
Modula offers a WMS Driver and WMS Link. WMS Link, for example, acts as a communications server and allows a WMS to control Modula units over TCP/IP.
SSI SCHAEFER supports higher-level integration for its LOGIMAT VLM, including the LOGIDRIVER interface for customers wanting to use their own software.
So if you tell me the exact VLM manufacturer/model, I would investigate its native interface before designing anything custom.
Define a canonical equipment API
Your middleware should expose a vendor-neutral set of operations such as:
POST /equipment/{id}/retrieve
POST /equipment/{id}/store
GET /equipment/{id}/status
GET /equipment/{id}/job/{jobId}
POST /equipment/{id}/cancel
POST /equipment/{id}/reset
A message broker can be useful if you have multiple machines or want durable queues, although REST can be perfectly adequate for a smaller installation. Existing VLM/WCS products demonstrate both REST/API and TCP/IP approaches.
PLC integration
If you do need to interface directly with the controls, I'd favor OPC UA where the PLC/control platform supports it.
OPC Foundation's ISA-95 model specifically addresses information exchange between WMS/MOM/enterprise systems and PLC/control systems.
But I would not expose arbitrary PLC tags to your WMS.
Then establish explicit transactional rules for what happens when:
the VLM says a pick failed
the operator picks the wrong quantity
communication drops after the machine accepts a job
the WMS times out but the VLM continues working
the same request is accidentally sent twice
a tray is physically moved without a WMS transaction
the PLC is rebooted during a pick
Idempotency and recovery are more important than the initial API.
What I would build
For a new system, my preferred stack would be:
Layer
Recommendation
WMS ↔ WCS
REST API + asynchronous events
WCS
Dedicated integration/service layer
WCS ↔ VLM
Manufacturer API/interface
PLC ↔ WCS
OPC UA where appropriate
Multiple machines
Queue/message broker
Job IDs
Globally unique + idempotent
Monitoring
Centralized equipment/job/event logging
Security
Network segmentation + authenticated APIs
Testing
VLM simulator before commissioning
The big advantage is that your WMS integration becomes stable even if the physical automation changes.
If you give me (1) the WMS you're using, (2) the VLM manufacturer/model, and (3) what PLC/control system runs the warehouse equipment—Allen-Bradley, Siemens, Beckhoff, etc., I can map out the actual integration architecture and protocols, including the specific APIs/interfaces I'd use and an example WMS↔WCS message specification.
