Modern third generation supervisory control and data acquisition, or SCADA, systems reply on LAN or WAN infrastructure and use shared and open IP protocols for communication. While one of the advantages of these SCADA systems is that they are easy to reach from the Internet, security problems arise as there is no secondary or backup monitoring, recording, and archiving solution.
The human-machine interface, or HMI, lies at the heart of any SCADA system and allows operators to monitor or control integrated elements in real time. Archiving all images that are displayed on the HMI is vital for safety, training, quality control, and legal purposes. In order for the system to capture and record all HMI operations however nevertheless continue security, an external device must be used and the SCADA system itself should not be changed in any way.
The solution to external SCADA monitoring and recording then is to use an external frame grabber that is independent of the SCADA system itself and operates on a different network infrastructure. For video capture of the HMI, an external network frame grabber that is able to grab images directly from the VGA steam should be used.
External grabbers act as a bridge between the SCADA HMI and a computer that is used for recording and archiving the captured images. An external network frame grabber, such as the VGA2Ethernet, is able to grab the DVI or VGA signal originating from the HMI, digitize it, compress it, and send it over a LAN to one or more computers, a safe repository, or an external server.
Using an external VGA frame grabber for video capture method that it is always possible to backup the information flow from the SCADA system into a far away and obtain location that is physically separated from the bulk of the SCADA system, adding another inner of security and management.