| In IP video management systems, the video recording function can be triggered by event detection. Event-driven recording instead of non-stop video recording saves a significant amount of system resources (e.g., hard disk space, bandwidth, and PCs). Generally, these events come from the video analytics (such as motion detection), digital inputs, and the http commands of the IP video surveillance system.
OPC Interoperability with HMI/SCADA and NVR
Now that we have integrated the video system with the automation system, the question is this: Can events come directly from the automation system? In principle, the answer is yes, but how can this be implemented? The solution is simple and easy as long as OPC commands are supported. Given that OPC (or OLE for process control) is commonly used in automation systems, why not use OPC communication to bridge the gap between the video system and the automation system, in which case event-triggered video recording is possible? For example, the SCADA system can send alarms to the NVR system via OPC commands, and when the NVR system receives a command, it triggers video recording. Finally, the NVR will send the recorded video back to the SCADA system via OPC.
Event Triggered Process
With most IP video surveillance systems, the events that a system can handle are limited due to system resource restrictions or device incompatibility. Luckily, for an integrated system this is not an issue. In fact, the type and quantity of events that can be handled are significantly increased, and the video recording system becomes more efficient, precise, and cost-effective.
Figure 1:
SCADA alarm triggered by field I/O from automation systems
Figure 2:
NVR triggered by SCADA/HMI events (alarms)
Figure 3:
NVR enables video recording and transmission from field sites
Figure 4:
SCADA operators can access NVR status and data for event monitoring
|