IO-Link provides a standardized data path. Predictive maintenance starts only when a failure mode, healthy baseline, decision threshold and maintenance action have been defined.
Ask the supplier to show which pressure, flow, status and diagnostic values the exact device exposes; how those values reach your PLC or maintenance system; which IODD and port class are required; and how parameters are restored after replacement.
Start with the failure, not the protocol.
Leakage, slow motion, vacuum loss or unstable supply.
Pressure, flow, travel time, position, status or event code.
Device to IO-Link master, PLC, HMI and maintenance system.
Threshold, alarm owner, work instruction and replacement plan.
Examples must be confirmed for the exact component. An IO-Link label does not guarantee that a valve, sensor or air-management unit exposes every signal listed here.
What IO-Link does—and what it does not do.
IO-Link is a standardized, bidirectional point-to-point interface between an IO-Link master and a field device. It can carry cyclic process data and value status, plus acyclic parameters and diagnostic events. The master connects that device-level data to the higher-level automation network.
The IODD describes the device identity, parameters, process-data structure and diagnostics. IO-Link itself does not create a failure model, choose an alarm threshold or decide which maintenance action should follow an event.
Replace “predictive-maintenance ready” with a testable statement: signal + failure mode + threshold + action + acceptance result.
12 questions to ask before you issue the PO.
- Data
Which cyclic process values are available, with what units, range and resolution?
- Data
What is the minimum device cycle time, and how is invalid data reported?
- Data
Which events and diagnostic codes are exposed, and what response is recommended for each?
- Evidence
Which failure mode can each value detect, and what validation evidence exists?
- Identity
Which IO-Link revision, Device ID and IODD version are supplied?
- Power
Does the device require Port Class A or B, and what are its power requirements?
- Integration
Which masters, PLCs and higher-level protocols have actually been tested?
- Mapping
Can the supplier provide the byte/bit data map and an integration example?
- Restore
Does parameter backup and restore work through the selected master?
- Logic
Where are baselines and alarm thresholds calculated and stored?
- Fallback
What happens when data, communication or supply power is interrupted?
- Lifecycle
What is the firmware, spare-parts, revision-control and security-support policy?
Turn supplier claims into documents and tests.
| Supplier claim | Evidence to request |
|---|---|
| “IO-Link compatible” | IODD, Device ID, revision and process-data map. |
| “Predictive-maintenance ready” | Failure mode, measured signal, baseline, threshold and maintenance action. |
| “Fast device replacement” | Demonstration of parameter backup and restoration with the selected master. |
| “Easy PLC integration” | Tested master/PLC combination and sample byte/bit mapping. |
| “Advanced diagnostics” | Complete event-code list with severity and recommended response. |
Prove the maintenance loop on a test rig.
- 01
Record a healthy baseline under the agreed pressure, flow, load and cycle conditions.
- 02
Introduce a controlled, safety-approved fault that represents the target failure mode.
- 03
Confirm the raw value, device event, PLC/HMI display, timestamp and alarm action.
- 04
Replace the device and verify parameter restoration through the selected master.
- 05
Save trends, configuration, IODD version and acceptance results in the handover pack.
Information to send with a smart-pneumatic enquiry.
- PLC and network protocol
- IO-Link master model
- Required Port Class A or B
- Supply pressure and required flow
- Ambient and ingress requirements
- Valve station and coil load
- Failure modes to monitor
- Required process values and diagnostics
- Maximum detection time
- Spare and parameter-restore procedure
Questions buyers ask most often.
Is IO-Link a fieldbus?
No. It is a standardized point-to-point interface between a master and a field device.
Does IO-Link automatically provide predictive maintenance?
No. It provides operational and diagnostic data; the project team still has to define the failure model, baseline, threshold and action.
What file is required to configure an IO-Link device?
Ask the supplier for the correct IODD for the exact device identity and revision.