Special Considerations

When the entire waveform data file is compressed, the following features are also activated:

1. The entire waveform data file fits within one screen width.

2. The cursor will not automatically be displayed, it must be manually enabled if initially disabled.

3. The ← and → cursor control keys are active, allowing the cursor to be moved in a left or right direction across the waveform(s).

4. The cursor position at any given location on the screen will define the center of the screen when the screen is expanded by reentering the Waveform Compression dialog box and entering a lower compression factor.

5. The following functions are available while within the compressed file format: CALC HOT KEY, CHANNEL SCALING AND OFFSET, EXPORT (at the current compression factor only), CURSOR ON/OFF, DISPLAY FORMAT SELECTION, DISTANCE TO END-OF-FILE, HARD COPY UTILITY (at any compression factor), JUMP TO BEGINNING/END OF FILE, QUIT, SEARCH-FOR-EVENT, SWITCH FILES, TIME MARKER, TIME-TO-BEGINNING-OF-FILE, and VARIABLE WAVEFORM ASSIGNMENTS.

6. The fully compressed file display is saved in memory to allow fast reentry when moving between lower (or uncompressed), and the full file compressed formats.

The Compression ratio (displayed in the compression menu or dialog box) is the number of data points for each enabled channel that are evaluated for a min/max value. For example, if the compression ratio equals twenty, then a min/max line is plotted for every twenty evaluated data points.

Cursor Mode Control (Mid, Min, Max, or MxMn) for compressed displays

The waveform compression function operates by accumulating n number of waveform samples (where n equals the compression ratio). From these samples, a line is then displayed, where the end points of the line equal the absolute minimum and maximum values detected for the sample group. When both the cursor and either Waveform Data or X-Y Plotting Operations functions are enabled, a dilemma exists regarding the appropriate value to report since multiple waveform segments have been compressed into one. To a degree, the cursor mode control solves this problem by allowing you to specify the value of a compressed line segment at cursor intersection as either its minimum, maximum, mid point, or minimum/maximum quantity. Mid reports the compressed line segments mid point value. Min reports the minimum value of the compressed line segment. Max reports the maximum value of the compressed line segment. MxMn reports both the maximum and the minimum compressed line segment values in a blood pressure like format (i.e., separated by a slash, such as 120/80).

You have the option of choosing between MID, MIN, MAX, and MxMn line segment reporting. To select the desired line segment reporting method:

  Click the desired radio option button (either MID, MIN, MAX, or MxMn). A dark dot will appear in the radio option button when selected. Then click OK.

   Press the TAB key until one of the three radio option buttons (MID, MIN, MAX, or MxMn) becomes selected. When a radio option button is selected, a dotted box will surround the option and a dark dot will appear in the radio option button. Press TAB until the OK command button becomes selected. Press ENTER.

The currently active cursor mode is automatically reported at the bottom of the screen where the normal DATA annotation is replaced by MIN, MAX, MID, or MxMn. The default state is MID.

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