A JSON object describing a Poll has the following syntax:

{
  "@Skill.ADS.Poll": {
    "name": "Poll",
    "UUID": "97edcbbf-e954-4e80-9169-936051625356",
    "ACL": { ... },
    "timeout": "1s",
    "strategy": "NotificationBased",
    "transmissionMode": "serverCycle",
    "maxDelay": "10us",
    "cycleTime": "1ms"
  }
}

Object Members

name	A string value containing the name of the Poll. The name is used to construct the Poll’s primary key.
UUID	A string value containing the unique UUID of the Poll.
ACL	An optional JSON object containing the element ACL of the Poll. The format of the object is described under JSON Format for ACLs in the Xentara user manual.
timeout	A time period used to set a timeout on read and write operations managed by this poll. The current operation will be canceled, connection will be assumed down and the proper error message will be reported in case of timeout.
strategy	A string value containing the update strategy of the poll. The strategy can be configured as “Polling” or “NotificationBased”. The default value is “Polling”. For more information refer to Update Strategies.
transmissionMode	A string value containing the transmission mode of the ADS notifications. The transmission mode can be configured as “serverCycle” or “serverOnChange”. The default value is “serverOnChange”. For more information refer to Transmission Mode Note The transmission mode configuration parameter is only available for polls with “NotificationBased” strategy.
maxDelay	A time period as the max delay parameter of the ADS notifications. The default value is 0. For more information refer to Max Delay Note The max delay configuration parameter is only available for polls with “NotificationBased” strategy.
cycleTime	A time period as the cycle time parameter of the ADS notifications. The default value is 0. For more information refer to Cycle Time Note The cycle time configuration parameter is only available for polls with “NotificationBased” strategy.

Update Strategies

Polling

Polls using the “Polling” update strategy refresh the values of their attached variables during each invocation of their “read” task.

Notification Based

Polls using “NotificationBased” update strategy register individual notifications for each of their attached variables. Upon receiving a notification from the target ADS device, the corresponding variable is updated with the new value.

Transmission Mode

Server Cycle

The “serverCycle” transmission mode causes update notifications for the variables to be received cyclically from the target ADS device.

Server On Change

The “serverOnChange” transmission mode causes update notifications for the variables to be received from the target ADS device only when their value changes.

Max Delay

Notifications will be received from the target ADS device no later than the specified time interval, which is defined in units of 100 nanoseconds.

Cycle Time

The target ADS device checks whether the variable has changed after each specified time interval, measured in units of 100 nanoseconds.