Solution:

To poll the device only when data is being accessed: 1. From the I/O Driver Power Tool Tree Browser, select the datablock you want to modify. 2. Enter DISABLED in the Secondary Rate field. 3. Enter a value other than DISABLED in the Access Time field. 4. In the Primary Rate field, enter a value that is close to the time that the data in the device is being updated. NOTE: If the datablock does not poll after you complete the previous steps, enter an alternate secondary poll time interval by resetting the access time for the datablock. When the access time expires, the driver polls at the new secondary poll time interval.