7.2.Configuring the System Monitor

  1. With the OPC DataHub running, right click on the DataHub system-tray icon and choose Properties.
  2. In the Properties window, select System Monitor .
    To enable system monitoring, check the Enable system monitoring box and edit the configuration options as desired:
    Data Domain:

    The name of any DataHub data domain. The values retrieved from the system will be shown as points in this data domain.

    Update Rate:

    The frequency that the system is polled and all selected points are updated. The minimum polling time is 100 ms., so the value entered here cannot be less than 100.


    A high update rate (a low number here) for many data points could use a great deal of CPU.

    When a parameter is invalid:

    A parameter will be invalid if the object being monitored is not available. For example, if a process is not running then the parameters for that process will all be invalid. This is a useful way to monitor a system process or other object. For example, you could use a script or other client to watch a process ID, and when the process ID becomes -1 you could generate an alarm indicating that the process is no longer running.

    Point Names:

    The System Monitor automatically creates OPC DataHub point names based on the names of the system properties. Some client programs cannot work with point names containing special characters. This section allows you to specify which characters will be removed from the property name when constructing the point name.

    Now you are ready to create the list of system parameters that you want to monitor.
  3. Click the Select From List button. This will open the Select System Properties dialog:

    Depending on your system, this dialog may take a few seconds to appear. If it does not come up, the Event Log will contain a message. Otherwise, just be patient, it will open eventually.

    In the Select System Properties dialog you can specify which items to add to your list of monitored system properties, according to these criteria:

      Performance object:A list of all available objects, such as CPU, Memory, Process, Print Queue, TCP, etc.

      Counters:All of the available data categories related to the selected performance object. You can choose all counters, or select specific counters from the list. The Explain button opens a window with an explanation of the selected counter.

      Instances:All of the instances of the chosen performance object. For example, if you chose Process for your performance, this list will show all of the processes running on your system. You can choose all processes or select specific processes from the list.

      A number in this list normally indicates a selection from multiple objects of a given type, and _Total means the total across all of the objects. For example, if you are looking at Processor in a multi-processor machine, you will see a number (0, 1, etc.) for each processor and a _Total for the cumulative statistic over all processors.

  4. Select a performance object, and counters and instances as applicable. For example, to see the process ID for DataSim, first ensure that DataSim is running, then select:

      Performance object:Process

      Select counters from list:ID Process

      Select instances from list:DataSim

  5. Click the Add button to add the selected items to the Monitor system parameter list in the DataHub Properties window.
  6. Click the Apply or OK button in the Properties window when you are finished making your choices and filling the list, to apply your changes. You should be able to view the results in the Data Browser.

    If you change your mind on what points to monitor, you can change the list at any time. Any points you remove from the list will continue to exist in the DataHub until it is shut down and restarted. Please refer to Section17.1, “Data Points” for more information on creating and deleting points.