3-28 BOP HIPWR 111315Each waveform has an identifying name, the operating mode (voltage or current), positive andnegative protection values, and the count (the number of times the complete waveform is to berepeated). Setting the count to zero allows the waveform to repeat continuously.A waveform is comprised of at least one, or as many as 10 segments. Each segment has anindividually specified value for Type, Frequency or Period, Amplitude, Offset, Start angle, Stopangle, and Initial/Repeat; see Table 3-11 for details. Refer to PAR. 3.3.9.4 to view a previouslysaved waveform, PAR. 3.3.9.6 to execute a previously saved waveform, PAR. 3.3.9.7 to modifya previously saved waveform, PAR. 3.3.9.8 to create a new waveform and PAR. 3.3.9.9 for anexample with detailed instructions on how to create a complex waveform.FIGURE 3-9. SAVED WAVEFORMS MENU3.3.9.3 UNDERSTANDING HOW WAVEFORMS ARE GENERATEDWaveform are generated by the BOP by producing a series of discrete output levels (points) in aprescribed pattern. In the case of sine, triangle and ramps, this produces an output that con-forms to an approximation of the selected waveform type. The number of points available for awaveform is limited to 3933 for all segments. Since there are a finite number of points, the lowerthe frequency, the more points used, and the smoother the output waveform will appear. As thefrequency increases, fewer points are available for each cycle and the resulting waveform mayappear somewhat more jagged. Tables 3-9 and 3-10 list the number of points used for each fre-quency range of sine, triangle and ramp waveforms and for square waveforms, respectively.Levels use a maximum of 60 points.This means that a waveform consisting of a single sinewave segment at 0.1 Hz will use all 3840points to generate each cycle, while a sinewave at 440 Hz will use 24 points for each cycle.Note that a single segment between 0.01Hz and 1.8Hz uses all available points, so subsequentsegments will not be accepted. Four segments of 10Hz will be acceptable, while five segmentsat 10 Hz will not be accepted. Reducing the segment by using the start and stop angle will alsoreduce the number of points used.Each time a segment is added, the waveform is validated. When a segment is added thatcauses the point total to exceed 3933, three asterisks *** will appear to the left of the segment,and the error message “LIST TOO SMALL” will be displayed briefly. This can be corrected byVOLTAGESOURCEVOLTAGE CURRENT0.0000 0.0000
