Video surveillance has been around for many years, but in order to monitor remote assets dedicated communications infrastructure for the video signal is required and the associated costs are normally very high.
In the traditional SCADA industries, such as water/wastewater, oil & gas, and power, it is common for customers to have field controllers or Remote Telemetry Units (RTUs), which monitor the signals from the process instruments making it possible to piggyback video over the existing communications infrastructure.
Regulatory compliance is also increasing, forcing customers to add video capability to monitor critical infrastructure and provide operators with an additional dimension in managing these processes.
The American Water Works Association (AWWA) and Water Environmental Federation (WEF) have developed a three-phased program to address physical infrastructure security and video camera/CCTV is an obvious solution.
When existing SCADA systems have communication infrastructure in place, such as radio networks, the video cameras can be connected to local video server software and send video images to the SCADA computer when abnormal conditions occur.
This way the SCADA network is not used for continuous video stream and conserves bandwidth.
When motion is detected an alarm is raised and the cameras record both image snapshots and video event clips during the period of motion.
Also, the video cameras can be setup with pan, tilt and zoom (PTZ) controls so that the operator can more efficiently investigate the alarm without having to physically be onsite.
Figure 1: The SCADA display shows real-time data incorporated with video image of a pump station site.
Control Microsystems has partnered with Longwatch, a provider of software to manage and integrate video with SCADA systems.
The product combination provides a remote security solution allowing operations staff to monitor both the physical security of sites as well as the expected operation of the system.
Figure 2: This shows a typical solution configured for ClearSCADA.
The system is made up of a number of key components:
- Cameras supporting pan, tilt, and zoom.
- The Longwatch video engine at each site to manage and buffer the real-time video.
- ClearSCADA host computer with Video Control software for video archiving and alarm management.
Field based cameras constantly record high resolution video at the remote site.
When an abnormal condition occurs, an ‘event clip’ – which is typically lower resolution to accommodate the communications network limitations – is sent back to the control centre based on predetermined triggers.
The high resolution video remains at the remote site and is stored within the remote video engine appliance. This mechanism also provides buffering in case the communications to the remote site is unavailable.
Further to this, communications between the remote site and control room can utilise existing infrastructure.
It is not necessary to install dedicated IP links for video as video information can be transmitted to the host computer on the same links already existing for SCADA data.
Where system communications utilise slow links such as 9600 baud serial radios, video data can still be transmitted back to the central computer.
ClearSCADA interfaces to the Video Control software using industry standard OPC. Therefore, points/tags can be configured to monitor for alarms, such as motion detection, used for pan, tilt and zoom (PTZ) control to move the cameras to pre-set positions, and to monitor parameters, such as communications bandwidth and video bit rates.
Once an alarm is detected, the operations staff can view the historical video clips and alarm information stored in the Video Control software.
This provides the ability for video information captured from the remote site to be compared to control process information in the same time period, allowing operators to see if physical issues are related to process disturbances.
Surveillance of remote assets using video technology provides greater visibility of real-time conditions.
When these assets are related to critical infrastructure, such as drinking water, pipelines, electrical substations and where governments around the world have mandated increased monitoring, video surveillance is a natural and efficient solution.
The Longwatch and ClearSCADA combination provides all the functionality to meet these requirements while minimising costs and implementation time by utilising existing SCADA networks.