Triggers
The following overview lists the triggers available in the OPC Client and shows at a glance whether they are supported by OPC Classic and/or OPC UA.
| Trigger | OPC Classic | OPC UA | Description |
|---|---|---|---|
| Bit Trigger | ✅ | ✅ | Triggers a transfer when a logical data point is set, and optionally supports response and error bits. |
| Threshold Trigger | ✅ | ✅ | Triggers a transfer when a data point exceeds or falls below a defined threshold. |
| Data Change Missing Trigger | ✅ | ✅ | Triggers a transfer when a monitored data point does not report a value change within a specified time period. |
| Data Change Trigger | ✅ | ✅ | Triggers a transfer upon a value change and can additionally be controlled via tolerances as well as minimum and maximum intervals. |
| Multi-Datachange-Trigger | – | ✅ | Dynamically monitors an OPC UA data point group and triggers the transfer upon changes within this group. |
| Message Trigger | ✅ | ✅ | Triggers a transfer when a numeric data point is incremented and optionally supports response and error data points. |
| Alarm/Event Trigger | – | ✅ | Responds to events from an OPC UA server and provides the associated event data for the transfer. |
Notes
- ✅ = supported
- – = not supported
- Multi-datachange triggers and alarm/event triggers are only available with OPC UA.