Determine frequency type shift

If a sample plan frequency is configured to generate future samples for a shift, then the QM specification that uses this sample plan frequency and has the highest specificity (and is currently effective), is used to generate future samples up to the end of the shift. If a QM specification is effective during a shift rather than at the beginning, the exact sample time is delayed until the sample frequency becomes effective.

The conditions to generate a sample plan based on the shift start offset and shift end offset are as follows:

• If the sample plan frequency contains a value for the shift start offset, then the first future sample for the current shift is generated. In this case, the sample request time is equal to the offset start from the current shift start time. Further samples are generated based on the effective time between samples.

• If the sample plan frequency contains a value for the shift end offset, then the last future sample for the current shift is generated. In this case, the sample request time is equal to the offset end from the current shift end time. The sample request time also includes the offset end from the current shift end time.

• If the number of times to take samples in a shift is specified instead of time between samples, the effective time between samples is calculated as:

  

• Before determining the effective time between samples, the offset_start value and offset_end value are added to the current shift start time and current shift end time, respectively. For example, the first sample is always requested at the beginning of the shift, if there is no offset, or at the offset start time from the beginning of the shift.

• The last sample is requested at the end of the shift, if there is no offset, or at the offset time from the end of the shift.

• The remaining sample requests are divided at equal intervals between the first sample requested time and the last sample time.

• The minimum number of samples requested for a shift must be at least 1, which will generate a single sample at the offset start time regardless of any other settings.

• If the number of times per shift and the interval are both specified, then the first sample is generated at the offset_start value. Additional samples are generated at the time interval up to a maximum of the number of times per shift or the shift end time minus the offset_end, whichever comes first.