Selecting the next data set for recording

To force the historical recorder to switch recording to a different data set at the end of the current interval, issue the F line command.

You can issue the F line command against only one data set per interval. After the command is issued, you must wait until the end of the current interval for command processing to be completed before you can issue this command against a different data set.

The F line command can be used only against a historical data set that has a Status field value of Closed and a Rec field value of Yes; it has no effect on data sets with any other status.

If the historical data set that you want to select has a Rec field value of No, issue the O line command to change its eligibility to Yes; see Changing-recording-eligibility.
If the historical data set that you want to select has a Status field value other than Closed, see Closing-a-data-set.

When the F line command is issued, the Pending field value changes to SEL PEND for the selected data set and to QUIESCED for the currently active data set.

When the current interval ends, results are as follows:

The historical recorder switches recording to the selected data set and writes the record for the interval that just ended.
The Status field changes to Active and the Pending field value changes back to asterisks for the selected data set.
The Status field changes to Qscd and the Pending field value retains a QUIESCED status for previously active data set.

Note

The previously active data set retains a QUIESCED pending state throughout the duration of the new interval. Data cannot be written to or read from this data set from the time the F line command is issued until the end of the new interval.

At the end of the new interval, the QUIESCED pending state ends automatically and the Pending field value changes to a Qscd status. A quiesced data set must be manually unquiesced to become eligible for recording or reading again. Issue the U line command to unquiesce a quiesced data set; see Reinstating-read-and-write-access-to-a-quiesced-data-set.

The following figure shows how to issue the F line command against a data set to force the historical recorder to switch recording to it at the end of the current interval.

Using the F line command to switch data set recording

ddmmmyyyy hh:mm:ss ------- MainView WINDOW INTERFACE (Vv.r.mm) ------------
COMMAND ===>                                               SCROLL ===> PAGE
CURR WIN ===> 1        ALT WIN ===>
>W1 =DSLIST===========SYSB=====*=======dd/mm/yyyy=hh:mm:ss====MVMVS==D=====3
C DDNAME   From Date Time To Date    Time Rec Status Pending Data set nam
- ------   ---------- ----- --------- ----- --- ------ ------- ------------
  HISTDS03 dd/mm/yyyy hh:mm dd/mm/yyyy hh:mm Yes Active ****** PROD1.IMAGSY
f HISTDS01 dd/mm/yyyy hh:mm dd/mm/yyyy hh:mm No Closed ****** PROD1.IMAGSY
  HISTDS02 dd/mm/yyyy hh:mm dd/mm/yyyy hh:mm Yes Closed ****** PROD1.IMAGSY

The following figure shows how the Pending field changes when you issue the F line command.

Pending field changes for the forced and active data sets

   ddmmmyyyy hh:mm:ss ------- MainView WINDOW INTERFACE (Vv.r.mm) ------------
COMMAND ===>                                               SCROLL ===> PAGE
CURR WIN ===> 1        ALT WIN ===>
>W1 =DSLIST===========SYSB=====*=======dd/mm/yyyy=hh:mm:ss====MVMVS==D=====3
C DDNAME   From Date Time To Date    Time Rec Status Pending   Data set n
- ------   ---------- ----- --------- ----- --- ------ -------   ----------
  HISTDS03 dd/mm/yyyy hh:mm dd/mm/yyyy hh:mm Yes Active QUIESCED PROD1.IMAG
  HISTDS01 dd/mm/yyyy hh:mm dd/mm/yyyy hh:mm No Closed SEL PEND PROD1.IMAG
  HISTDS02 dd/mm/yyyy hh:mm dd/mm/yyyy hh:mm Yes Closed ******** PROD1.IMAG

The following figure shows how the Status field changes at the end of the current interval. Also note that the data sets are reordered because they are sorted on the From Date and Time fields.

End-of-interval status field changes

ddmmmyyyy hh:mm:ss ------- MainView WINDOW INTERFACE (Vv.r.mm) ------------
COMMAND ===>                                               SCROLL ===> PAGE
CURR WIN ===> 1        ALT WIN ===>
>W1 =DSLIST===========SYSB=====*=======dd/mm/yyyy=hh:mm:ss====MVMVS==D=====3
C DDNAME   From Date Time To Date    Time Rec Status Pending   Data set n
- ------   ---------- ----- --------- ----- --- ------ -------   ----------
  HISTDS01 dd/mm/yyyy hh:mm dd/mm/yyyy hh:mm Yes Active ******** PROD1.IMAG
  HISTDS03 dd/mm/yyyy hh:mm dd/mm/yyyy hh:mm Yes Qscd   QUIESCED PROD1.IMAG
  HISTDS02 dd/mm/yyyy hh:mm dd/mm/yyyy hh:mm No Closed ******** PROD1.IMAG

The following figure shows how the Pending field changes at the end of the new interval.

Pending field change

   ddmmmyyyy hh:mm:ss ------- MainView WINDOW INTERFACE (Vv.r.mm) ------------
COMMAND ===>                                               SCROLL ===> PAGE
CURR WIN ===> 1        ALT WIN ===>
>W1 =DSLIST===========SYSB=====*=======dd/mm/yyyy=hh:mm:ss====MVMVS==D=====3
C DDNAME   From Date Time To Date    Time Rec Status Pending   Data set n
- ------   ---------- ----- --------- ----- --- ------ -------   ----------
  HISTDS01 dd/mm/yyyy hh:mm dd/mm/yyyy hh:mm Yes Active ******** PROD1.IMAG
  HISTDS03 dd/mm/yyyy hh:mm dd/mm/yyyy hh:mm Yes Qscd   ******** PROD1.IMAG
  HISTDS02 dd/mm/yyyy hh:mm dd/mm/yyyy hh:mm No Closed ******** PROD1.IMAG

Selecting the next data set for recording

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