Many of the parameters in the trend log object are definable only if:
- Enable for logging (Enable logging) [EnLog] is inactive
- The log buffer is empty (Record count = 1)
- In this state, the following variables can be modified:
- Start time [TiStt] and stop time [TiStp]
- Interval [Ivl]
- Buffer size [BufSize]
- Record count [RecCnt] (can only be overwritten with 0: delete log buffer)
- Notification threshold [NotifThd]
- Input/Output address [IOAddr] (if an unavailable BACnet address is entered, an alarm is initiated)
- [EnLog] is inactive or active
- The log buffer is not empty (log count > 1)
- In this state, only the following parameters can be configured:
- Start time [TiStt] and stop time [TiStp]
- Record count [RecCnt] (can only be overwritten with 0: delete log buffer)
- Notification threshold [NotifThd]
The record count [RecCnt] can only be overwritten with 0. This deletes all the log data. After a write operation of 0, there is one entry showing the log status (record count = 1).
It is not possible to reload sampled data into the CFC Editor.
With a full loading procedure, any previously sampled data will be lost. With differential or delta loading the data will not be lost.
The PXM20 stores modified parameters in its internal memory cache. To display the data actually written, you must exit from the trend log object and re-select it.