Archive table (PIARC)
- Last UpdatedJan 13, 2023
- 1 minute read
- PI System
- PI Server
The PIARC table provides access to PI point data in the archives. The archives are historical records of values for each point in the PI point database. The archives store the time-stamped values in a set of files. You can list, add, modify, or delete events. The primary key is TAG.
|
PIARC Attributes |
Description |
Comment |
|
TAG |
Tag name |
(read only) |
|
PointID |
Point ID |
(read only) |
|
Type |
Point type (for example, Float32) |
(read only) |
|
Value |
||
|
TIME |
Event timestamp in the format DD-MMM-YY hh:mm:ss.ssss |
|
|
TimeNum |
Timestamp as a number in seconds past 01-Jan-70 |
(read only) |
|
Status |
Value status |
(read only) |
|
Flags |
(Q)uestionable (M)odifed (A)nnotated |
Only Q is read/write |
|
Annot |
Annotation |
|
|
NewValue |
New value for specific replacement |
These attributes are the same as the PISNAP table attributes. In addition there are some auxiliary attributes that affect retrieval and editing:
|
Attribute |
Description |
|
Count |
Maximum number of events to retrieve in list mode |
|
Mode |
Archive editing mode |
|
Starttime |
Start time for events retrieval |
|
Endtime |
End time for events retrieval |
Starttime and Endtime can define both a forward and a backward search.
Events can be added to the snapshot using the PIARC table. Events are placed in the snapshot if they are more recent than the current snapshot event; otherwise, they bypass compression and go straight to the archive according to the archiving mode specified. When a new snapshot event is stored, the previous snapshot event is sent to the archive, compressed according to the compression specifications.