Laurel Electronics LTE SERIES TRANSMITTERS PULSE INPUT - Manual (Page 22)

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together and selecting a positive or negative edge to start (Slope A) and the opposite polarity
edge to stop (Slope B). If multiple start and stop pulses occur during the Gate Time, the
displayed value is the average of pulse widths. The value is updated at the end of each Gate
Time. With a scale factor of 1, one count is one microsecond.
• Stopwatch A to A times individual events applied to Channel A (Item #1) and the accu-
mulated “Grand Total Time” of all events since last reset (Item #2). Timing is based on the
same positive (or negative) edge of start and stop pulses. Time of individual events is reset
to 0 when a new start pulse occurs. Time of accumulated events is reset via a reset line.
With a scale factor of 1, one count is one microsecond.
•
Stopwatch A to B measures time between a start pulse on Channel A and a stop pulse on
Channel B. Timing is the same as for A to A, except that positive or negative edges may be
selected separately for Channels A and B. This allows the pulse width measurement of single
pulses by tying Channels A and B together. One slope is selected to start timing, and the
opposite slope to stop timing.
PHASE ANGLE (Extended counter).
• Phase A to B (0-360) measures the phase difference between signals of the same period
applied to Channels A and B over a span from 0° to 360°. Select this span if no negative
readings are expected, as negative readings would cause high readings.
•
Phase A to B (+/-180) measures the phase difference between signals of the same period
applied to Channels A and B over a span from -180° to +180°. Select this span if negative
readings are expected, which will then not cause high readings.
POWER FACTOR (Extended counter).
•
Power factor of an AC power system is the ratio of real power in watts (W) divided by
apparent power in volt-amperes (VA). For sinusoidal signals, power factor is calculated from
phase angle θ as cos(θ). Power factor readings can range from 1.000 to 0.000 with three
decimal places and an accuracy of 0.1% for sinusoidal signals at 50/60 Hz. While power
factor is always positive, a minus sign is artificially assigned for negative phase angles, and
power factor is set to 0 for phase angles greater than 90°.
DUTY CYCLE (Extended counter)
•
Duty Cycle (A to B)/A measures On or Off period of periodic square waves as a percentage
of total period over a Gate Time which is selectable from 10 ms to 199.99 s. The same signal
is applied to Channels A and B. Time is measured between positive and negative edges of
the signal, with averaging over multiple integral periods over the selected Gate Time. Scaling
can be via Scale and Offset, or the Coordinates of 2 Points method.