BACnetTrendLog (FB)

FUNCTION_BLOCK PUBLIC BACnetTrendLog EXTENDS BACnetStaticObjectBase IMPLEMENTS IBACnetTrendLog

FB reflecting a BACnet-TrendLog-Object. All Properties of this FB give access to the client writeable BACnet-Properties of the reflected BACnet-Object, although the access is done not client sided (without checking access restrictions).

Note

The pure functionality of storing Log-Values in a file or else where is (right now) not predefined by this FB. This means for storing Log-Values one has to register a Event-Callback-FB for the BACNET_CALLBACK_WRITE-Callback. In this callback the user has to check if the Log_Buffer-BACnet-Property of this BACnet-Object is written, and has to write the first value of this list to the corresponding file or else where. Additionally a Event-Hook-FB for the CB_READ_RANGE-Hook has to be regsitered and used to give back the whole Range of values stored (in a file or else where). For more details, see stack specification. Moreover access right behaviour which changes due to dynamically changing BACnet-Property-Sets is done by an Event-Callback (BACnetEventCallback), which is attached to the BACNET_CALLBACK_WRITE-Callback. Additionally see documentation of BACnetObjectBase. Moreover this is the reason why not havin the Log_Buffer-Property available in this FB.*)