Two types of limit lines can be specified, lower limit lines and upper limit lines. Limit lines can be used for visual reference only, or for pass/fail criteria using the limit alarm (
Figure: IA Limit Menu). Limit alarm failures are reported whenever a signal is above the upper limit line or below the lower limit line. By using save‑on‑event, a signal that causes a limit alarm can be automatically saved. Refer to your User Guide for details.
Each limit line can consist of a single segment, or as many as 40 segments. These limit segments are retained regardless of the current frequency span of the instrument, which allows the configuring of specific limit envelopes at various frequencies of interest without having to re‑configure them each time the frequency is changed.