Poll groups

In comparison to the spontaneous query the polling is a cyclic query with the set polling parameters. The desired poll interval with the single polling parameters do not have to be defined for each data point element but can be summarized in a poll group. You should note here that the summarization for the DPEs should take place with similar communication characteristics.

The polling parameters of some drivers have to be set in an own panel. Poll groups, which are provided with specific parameters (e.g. poll time and synchronization time) for the polling function, have to be defined. These groups can be chosen from a combo box in the configuration panel for the peripheral address (in the PARA module) if the receive mode polling is set.

Open the panel for defining the poll groups via the system management panel:

Figure: System management - Drivers tab

Click on the Poll groups button. Configure the single groups in the following configuration panel. An internal data point of type _PollGroup is created per group.

Figure: Configuration panel of the poll groups

• Create
  Creates a new poll group. After creating the device the further parameters can be set for the particular group. These are saved in an internal data point. If you want to change the settings, choose the poll group from the combo box, specify e.g. another poll time and click on Apply.

• Remove
  Removes the chosen poll group (a window for confirming the deletion is displayed).
   

• Mode
  Define which parameters should be set for the poll group. You can choose Poll time (for short poll times, typically 100ms to 60 seconds), Synchronization time (for long poll times, typically > 60 seconds to months; here you define a time for the polling) or Both. Configure the times in the panel after choosing the mode. 

• Synchronization time
  You can specify a start time for the polling in the bottom right part of the panel. Unless a polling is in progress a new cycle is triggered according to the time settings. There are monthly, weekly, daily and hourly invocations as well as invocations at minute or second intervals. Define the day of month for triggering the action in the Day combo box. The polling is triggered at the specified time (Hour and Minute spin button).  If you want to trigger the polling weekly, define the desired week day (Monday, Tuesday, ... Sunday). The hour and minute entries of daily polling refer to the time of day, the hour, minute or second entries refer to time intervals. In case of polling daily, 0:30 means polling every day half an hour after midnight, if you choose every hr./min., a polling every 30 minutes is executed.

Caution

• If you specify 31 as a day the polling is performed only every second month, if you again specify 30 the polling is performed every month except the February and in case of 29 additionally in the February of a leap year.

• When using Synchronisation based on seconds, the Poll time must be higher than the synchronisation interval or else the synchronisation mechanism will not be used.

• Poll time [ms]
  Specify how many seconds should elapse from the beginning of the polling until the next polling in the poll time field. Polling times that last over minutes can be defined easier via the synchronization time fields. If you define a poll time between 1 and 99 ms, a correction to 0 or 100 will be made while clicking on the Spin button contingent on the direction. I.e. only poll times >= 100 ms can be configured.

• Activating
  Activate the check box Poll group active to activate or deactivate the polling of a group.

• OK: Applies the settings or changes and closes the panel.

• Cancel: Cancels the settings or changes and closes the panel.

• Apply: Applies the settings without closing the panel.

• Help: Opens this side of the Online Help.

Note

For older projects (updated to 3.0) the polling parameters for the peripheral address are set in the configuration panel at existing configs. If a config for the peripheral address is appended newly to a DPE, the configuration of the polling parameters has to be defined via the poll groups.

Caution

Note that a poll group doesn't represent a poll request. The poll request depends on the configuration of the driver.