Model TT339-0700
4-Wire Isolated Frequency Transmitter w/USB
Acromag, Inc. Tel: 248-295-0880
[
20
]
http://www.acromag.com
Configuration...
HELP:
Press
[F1]
for Help on a selected or highlighted field
or control. Alternatively, click the
[?]
button in the
upper-right hand corner of the window and click a
field or control to receive a Help message pertaining
to the item pointed to.
Select the Excitation...
Select either Enable to p5VDC to the +EXC terminal, or
Disable to turn off excitation supply. Excitation is internally limited
to 20mA, typical.
Enter the Cutoff Frequency...
The
Cutoff Frequency
controls the minimum frequency the
transmitter will measure. When the frequency of the input signal
falls below the
Cutoff Frequency
, the transmitter will measure
0Hz.
NOTE:
Once the
Cutoff Frequency
is reached, the transmitter will
retain the last measurement and will wait a specified duration
before measuring 0Hz. This duration is equal to the period of the
Cutoff Frequency
. If no input is captured within this duration, the
transmitter will measure 0Hz. For example, a 0.25Hz
Cutoff
Frequency
would configure the transmitter to wait 4 seconds
before measuring 0Hz.
Enter the number of Samples to Average...
This transmitter captures and saves samples in a FIFO (first-in,
first-out) queue. The number of samples in this queue is equal to
the number of
Samples to Average
. The FIFO queue is used to
calculate a running average. Samples are added to the FIFO queue
at the Output Update rate.
NOTE:
It is often useful when measuring a gear using a magnetic
pickup to set the number of
Samples to Average
equal to the
number of teeth on the gear. Using this technique, variations in
gear teeth spacing will be averaged over one revolution, yielding a
constant frequency measurement.
Enter the Debounce...
The
Debounce
time controls the length of time the transmitter will
wait until the input signal is steady (not crossing threshold) before
measuring the input signal.
NOTE:
Debounce
is useful for filtering out temporary signal
glitches such as those generated by contact relays. For best
results, set the
Debounce
to twice the expected duration of
contact bounce.
