Unable to View Files in Historical Data Viewer

Updated Apr 9, 2019

Issue Details

I had taken data from the Historical Data Viewer (HDV) database and archived them into a .rar/.zip folder. I have extracted the relevant files to the database folder. However, I am now unable to see the data.

Solution

The reason it may not be possible to view the files is that the Historical Data Viewer needs certain files to be present in order to view the data. The list of which files are needed and what ones can be regenerated can be found below.

Citadel 4 
Historical Data Files
File NameDescription
thd00001.thdStores the actual historical data. Contains the pages of data from the traces. Each page is 4096 bytes. There are 256 pages per file, with 256 additional bytes of header information.
tdb.tdbThis file defines the database. It includes trace names, database version info, and other similar information. If this file is lost or corrupted, you will need the backup file to recover.
tdb.bakThe backup for the tdb.tdb file. If both this file and the tbd.tbd file are lost or corrupted, data cannot be recovered.
tdx.tdxTemporary meta block and page index. This contains a quick-lookup index for the components of a trace to speed up viewing of the database. This file will be regenerated if lost. It takes a while to regenerate if your database is large.

This would mean that if tdb.bak and tdb.tdb are missing, your data will not be recoverable.

Citadel 5

 
Historical Data Files
File NameDescription
cx00000001.cdpgData file(s).  This is equivalent to the *.thd extension in Citadel 4.
ix00000001.cdibPart of the page index files.  This is part of the *.tdx extension in Citadel 4.
stridm.cdinSub-index file. This is part of the *.tdx extension in Citadel 4.
pid.cdihHeader of page index file.  This is part of the *.tdx extension in Citadel 4.
nodetree.elogNode tree for browsing the database, high-level index file.  This is part of the *.tdb extension in Citadel 4.
nodetree.elog.ckpt0 (or .pt1Raw backup file of nodetree, pt0/pt1 are alternating files extensions to give maximum robustness.  This is part of the *.tdb extension in Citadel 4.
nodetree.elog.cpctCompacted backup file of nodetree.  This is part of the *.tdb and *.bak extensions in Citadel 4.

This would mean that if nodetree.elog.ckpt0 (or .pt1) and nodetree.elog.cpct are missing, your data will not be recoverable.
 

Additional Information

The Historical Data Viewer can also have Alarms and Events set. This is something that can be regenerated and will not be required in order the view data. It is best practice to keep these files present. More information surrounding what the files types within Alarms and Events can be found here.

Avoid placing any other type of files with the files from Historical Data Viewer files other than the ones it generates. This could also be the cause of issues.

Avoiding Issue:
To avoid this issue in the future then you would need to follow the instructions outlined in Logging Data with National Instruments Citadel: Section 3. Citadel Operations .