HP 5335A - Page 40

Operation and Programming
if the gate is reopened, data will once again be sent. The output data byte sent whiie the gate
is open is not preceded by the Alpha Character "T”, whiie the data sent after the gate is
closed is. For further information on the data output format, refer to paragraph 3-191.
NOTE
Totalizing on the fly should be performed only on signals below 50 Hz.
3-115. RATIO A/B
3-116. The RATIO A/B mode allows the measuring of the ratio between two frequencies. The
maximum frequency into Channel A is 200 MHz, and into Channel B it is 100 MHz. The ratio is
measured by connecting the original frequency into Channel B and the multiplied frequency
into Channel A. The counter will display the multiplying factor "N”. The number of digits of
resolution is determined by the input frequencies and the Gate Time.
ORIG I N AL
FREQUENCY
FREQUENCY
MULTIPLIER
XN
MULTIPLIED
** FREQUENCY
-S> TO CHAN A
-^TO CHAN B
3-117. FREQ C
3-118. The FREQ C mode requires the optional C Channel Input Module. Input signals to
INPUT C are prescaled by a-factor-of-20, however, as with FREQ A, there is no loss of resolution.
When FREQ C is selected, theChannei Aand B INPUT section is disabled. Measurements through
C Channel respond to ail other controls the same as FREQ A measurement.
3-119. 1/TiME A—B
3-120. The 1/TIME A—B mode performs the standard TIME A-*B measurement, mathematically
computes the reciprocal value and displays it as units per second. This allows measurement
configurations with a direct display of velocity. This mode can also utilize the stop channel delay
holdoff (T.l. DELAY) feature, described for TIME A—B.
3-121. To determine the velocity of a moving object, connect the START electric eye to
Channel A, and the STOP electric eye to Channel B. Select the 1/TIME A—B function. In this
example the two electric eyes are 10 metres apart, so compensate by setting SCALE to 10. This
will produce a measurement readout in metres/per second. If the bail takes 0.25 seconds to
travel between the electric eyes, the answer displayed will be 40 (metres per second). If a 0 ns
time is measured, a result will be displayed.
6 *
START
ELECTRIC
EYE
10 METRES
STOP
ELECTRIC
EYE
3-24
Model 5335A