Types of common video driver properties

In keeping with the standard NiagaraAX driver architectural model, many of the Video Driver components, device extensions, and WorkbenchAX views resemble those in other NiagaraNetwork drivers. In addition, many video-related components have properties that are common to the NiagaraAX environment. Figure 13 shows a comparison between a NiagaraNetwork property sheet and a VideoDriver Network property sheet.

Figure 13. Comparison between NiagaraNetwork and Video Driver properties

Common properties (described in the NiagaraAX-3.x Drivers Guide) include:

Status
Enabled
Fault Cause
Health
Alarm Source Info
Monitor
Tuning Policies

Other significant properties that are unique to specific video drivers are listed below:

Fox Video Stream Preferred

This property allows you to select or decline the use of Fox Streaming. The following paragraphs describe the effects of these two options.
- true
  
  The true option enables Fox Streaming. This means that the video stream is sent from the video camera to the station (Controller) and then forwarded to the WorkbenchAX interface through the standard Fox connection. This overcomes firewall issues in the event that the video surveillance system is not exposed to the outside world on its network
  
  This assumes that the controller is exposed - otherwise you could not even connect to the station.
  
  If this option is selected, then you should consider setting the resolution and frame Rate to Low and the compression to High in order to preserve CPU usage in the station (controller).
  Empirical analysis on the Dedicated Micros driver revealed that CPU utilization on a JACE 6 while streaming one low frame rate Fox Video Stream is 5 to 10 percent. Utilization for one high frame rate fox video stream is around 40 percent!
- false
  
  If false, then the video stream is sent directly from the video camera to the WorkbenchAX interface. Using this setting allows you to set the resolution and Frame Rate to High without having to worry about reducing the station (Jace) CPU - the station is removed from the equation. In either case, the client-side computer expends some of its CPU utilization to render the video on the screen.
  CPU usage varies greatly depending on the capabilities of the client-side PC. During testing, even an 800 Mhz Pentium III PC with 256 MB RAM running Windows 2000 with Mozilla Firefox or Microsoft Internet Explorer was able to easily render at least one video feed. Typically this method can only be used when the client browser or WorkbenchAX interface is accessed through a VPN connection. In this configuration, both the NiagaraAX station and the remote client must connect to the video device using the same IP address.
- inherit (some drivers)
  
  When selected, the inherit option causes a camera to use the value for this property that is set at it’s parent component (whether the parent is a DVR or a Network component).
  
  For example, if the parent component’s Fox Video Stream Preferred property is set to true, then the camera component also uses the value of true. In this example, if the parent is a DVR device, the DVR device may also have an inherit option set. If so, the value from the Network Device’s Fox Video Stream Preferred property is used.
Events Receiver

This property contains parameters related to event communication. The following property values are configurable:
- Enabled
  
  Set this parameter option to true to enable or false to disable the Events Receiver property.
- Tcp Ip Port
  
  Specify the Tcp Ip port to use in this text field.
- Socket Timeout
  
  Specify a time, in milliseconds, for timeout on the Events Receiver communication.

In addition to the properties listed here, many of the widgets that are provided in the videoDriver palette Px folder have common properties that are described in Common videoDriver widget properties.