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.
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?
Modula (Modula WMS / WCS) - Offers robust control software designed specifically to manage VLM fleets, optimize tray positioning, and interface with host enterprise systems.
Ferret / Savoye / Dematic - Enterprise-grade WCS providers capable of orchestrating multi-vendor automation, linking traditional conveyors, AMRs, and vertical storage lifts into a single unified material flow.
ICAM / Kardex / SSI Schaefer - Traditional systems integrators that build custom WCS layers to harmonize mixed automation environments.
Key Integration Considerations
Host Connectivity: Ensure the WCS supports standard APIs, database tables, or socket communication to talk seamlessly to your existing WMS or ERP.
Batch and Order Sequencing: The software should intelligently batch picks across multiple VLMs to minimize wait times (e.g., while one tray is being picked, the next tray is already being retrieved).
Ergonomic & Light Guidance Integration: Look for a WCS that natively drives pick-to-light, put-to-light, or laser pointer indicators on the VLM access point to maintain high accuracy (>99.9%).[](https://www.youtube.com/watch?v=4uKM_fhQdSw&t=1)
To help narrow down the best WCS platform for your facility, could you share:
Which brand of VLMs you are using or planning to purchase (e.g., Kardex, Modula, Hänel, Remstar)?
What WMS or ERP system the control software needs to sync with?
If you're looking for a Warehouse Control System (WCS) that integrates with Vertical Lift Modules (VLMs), I'd focus on solutions that can control automated storage and retrieval equipment, manage inventory locations, and coordinate picking workflows across your warehouse.
The key decision is whether you need a standalone system to control VLMs or a broader WCS that coordinates VLMs alongside conveyors, autonomous mobile robots (AMRs), sortation, and your existing Warehouse Management System (WMS).
WCS solutions worth evaluating
1. wms.Studio MPX
(Best for mixed VLM brands)
Designed to control VLMs from multiple manufacturers, including Kardex, Hänel, Modula, Weland, and Logimat. It can also coordinate conveyors, AGVs, and pick-to-light workflows. A strong candidate if you want one software platform across different equipment brands.
Website:
2. SRT WCS by Streamline-It
A broader warehouse execution and control platform that integrates vertical storage systems with robots, AMRs, and other automation. The vendor describes direct control of Ferretto VLMs, making it worth evaluating if you need to synchronize multiple automated processes rather than simply manage a lift.
Website:
3. Kardex JMIF
An integration layer for connecting Kardex automated storage equipment to an external WMS, WCS, or ERP. Consider this if you already have Kardex VLMs and want to retain your existing warehouse software while integrating equipment control. Confirm whether the scope covers all your required workflows.
Website:
4. Ascent Warehouse Logistics WCS
Worth considering for a custom integration project. Ascent describes a WCS that interfaces directly with PLC-based controls for VLMs, carousels, and other warehouse automation, potentially avoiding an additional OEM software layer.
Website:
5. ControlPoint WCS
A potential fit for mid-market facilities that need to coordinate equipment from multiple vendors. It supports a range of PLC and WMS integrations, but I would ask the vendor to demonstrate compatibility with your exact VLM make, model, and controller before shortlisting it.
Website:
What I would prioritize
Requirement
What to verify
VLM connectivity
Direct integration or supported OEM interface for your exact model
WMS/ERP integration
API, messaging, or other supported connection to your existing system
Inventory management
Real-time tray/bin inventory, location tracking, and reconciliation
Picking workflows
Batch picking, multi-order picking, pick-to-light, and replenishment
Multi-equipment control
Coordination of VLMs with conveyors, AMRs, or other automation
Reliability
Let me narrow this down to the best fit
Three details will make the shortlist much more useful.
1. Which VLM manufacturer do you use?
Kardex
Hänel
Modula
Ferretto
Multiple brands
Other / not yet selected
2. What do you want the system to control?
VLMs only
VLMs plus conveyors, robots, AMRs, or other automation
Entire warehouse execution, including inventory and order workflows
3. What warehouse software do you currently have?
An existing WMS that must remain
ERP only
No existing WMS or WCS
Replacing our current warehouse software
[Find the best-fit systems]
With those answers, I can narrow the options to the most relevant vendors and identify which ones are worth contacting for a technical demonstration.
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.
Fault recovery, offline handling, audit trails, and vendor support
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.
