The Video Historian enables users to examine stored video to compare operator actions and process procedures, improve machine control and process operations, identify control problems, and study the actions of machines, people and equipment. The historian can recall any video clip, or a series of related clips, for playback on the HMI screen. The user can "filter" clips according to starting times, batch IDs, production lines, cameras or similar criteria. Multiple video clips can be viewed individually, side by side, or four at a time, and each video window has its own controls for forward, reverse, play and pause. A "synchronize" toggle button on the screen allows video clips to be "synced" with each other.
This function allows engineers to compare operator actions, observe process equipment under various conditions, or look for abnormalities between process segments to answer questions such as: Why was this batch different? Why does the valve fail open? What causes the pipe to leak? Why does the robot miss picking up the part? Did the operator actually complete that step?
The Longwatch system is based on a distributed system architecture that provides video storage in the plant or remote areas, near the cameras. The distributed architecture provides for better scalability and fault tolerance; it also enables the user to better manage the load on his/her network, especially during plant upsets. Longwatch software may be deployed on Longwatch appliances or customer-supplied PCs. Streaming video is stored on each device, all of which can be directed to expandable local- or network-based storage devices. Historian video clips are saved in a central SQL database.
Process historians archive all relevant information about process conditions before, during and after a process for later analysis. The Video Historian adds video clips, referenced to process or manufacturing steps, control tags or other data to enable inclusion of the relevant video for plant operations and analysis.
Longwatch enables users to manage video on their network
Continuous video is stored remotely in high-resolution format by the Longwatch Video Engines and/or external storage devices for up to 30 days or more. When requested or triggered, video clips are sent to the control room by the Video Engine with a user-selected resolution that is appropriate for the plant's networking capabilities to minimize impact on communications. The "video packets" are sent over the network (either Ethernet or proprietary process) in such a manner as to not interfere with real-time process control activities. In systems using a high-speed network, the Historian can also provide video playback at the HMI of continuous video from any of the Video Engines. In both cases, high-resolution video images can be obtained easily when needed for evidence or for further examination from the Video Engines.
The Longwatch Video System is the only video system specifically designed for full integration with HMI and SCADA systems, and with data historians. Its distributed system architecture is designed to coexist with existing network infrastructures regardless of the networking protocols or bandwidth, thus improving utilization of current infrastructure and providing the capability to scale as new networks are deployed.