History recovery and archive data collection parameters

/dc

Optional

Apply compression specifications to history recovery and archive scan updates.

/fd=#(Unit)

Optional

Default: /fd=0s

For future tags, sets how far into the future the interface should search for data. Available units are seconds (s), minutes (m), hours (h), days (d), months (M), and years (y). Only a single unit can be used. Units are case-sensitive.

For example, /fd=30d would mean that each scan, the interface searches for values between the time of the last scan and the current time + 30 days.

By default, the interface does not search into the future.

Note: 1M=30d and 1y=365d.

/hronly [=<start,end>] Optional

INI File Setting: HistOnly

Specifies the time range to be recovered. The interface recovers data for the specified period, then exits. To disable exception data collection, omit time period.

Specify the times using PI time string formats with a colon or underscore separating the date and the time:

/hronly=dd-mmm-yy:hh:mm:ss,dd-mmm-yy:hh:mm:ss

or

/hronly =dd-mmm-yy_hh:mm:ss,dd-mmm-yy_hh:mm:ss

For example: /hronly=10-dec-98:10:00,10- dec-98:12:00

or

/hronly=10-dec-98_10:00,10-dec-98_12:00

Time stamps should use the interface node's local time.

Note: Data Archive-level failover cannot be configured when /hronly is used.

/hrpause=#

Optional

INI File Setting: HistPause

Default: /hrpause=0

Milliseconds to pause between points during history recovery. Used to throttle archive data retrieval during history recovery.

/mh=x

Optional

Default: /mh=1000

Minimum: /mh=1

Maximum: /mh=10000

Supported for target Data Archive version 3.3 or later.

Sets the maximum number of archive events retrieved per data request. If more than the maximum exist, the interface makes multiple calls until all events are retrieved for the time period. Increasing the maximum can increase data throughput for archive data retrieval.

/ns

Optional

Start history recovery beginning with the first value prior to the start time. By default, recovery begins with the first value after the start time.

/rh=#

Optional INI File Setting: HistRecovery

Default: /rh=8

Hours of history recovery to perform. No maximum is enforced, but be sure you have sufficient disk space for the archive files on the target server computer.

For additional information on backfilling data, see the Backfilling management section of the Data Archive Administration guide.

/rh_inc=#

Optional

INI File Setting: MaxArcTimespan

Default: /rh_inc=24

Time increments within the total /rhrecovery period.

For example, if /rh=48 and /rh_inc=24, the interface cycles through the point list twice. On the first cycle, the first 24-hour period is recovered. On the second cycle, the second 24-hour period is recovered.

/rh_qcheck=#

Optional

Default: /rh_qcheck=5

For exception data scan classes, specify how often to clear the exception queue on the source PI Data Archive during history recovery.

To prevent queue overflow, the interface periodically collects exceptions from the source Data Archive during history recovery. You can adjust this time interval to tune history recovery performance.

/me=#

Optional

Default: /me=10,000

Sets the maximum number of exception events retrieved per data request. A large count reduces the number of calls required to read exception updates. A small count reduces the time to complete each request (for troubleshooting network timeout issues).

/sn

Optional

Disable exception filtering for data collected from the source Data Archive. This data has already passed exception for the source tag. Additional data filtering can lead to data mismatches between Data Archives.