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9.1 RATE & FREQUENCY MODES
Frequency in Hz
is determined by timing an integral number of pulses over a user-specified
Gate Time from 0 to 199.99 sec and taking the inverse of average period. The typical internal
display update rate is Gate Time + 1 30 ms. Selecting a longer Gate Time produces a
more stable reading as more cycles are averaged, but slows down the update rate. At very low
frequencies, the update rate is controlled by the period. A Time Out from 0 to 199.99 sec is also
selectable. This is the time the transmitter waits for a signal to start or end a conversion. If the
signal is not received before the Time Out ends, the transmitter reads zero. The longer the Time
Out, the lower the minimum frequency that can be processed.
Rate in engineering units
can be obtained by applying a scale factor to frequency, or by using
the Coordinates of 2 Points method, where two inputs in Hz and the corresponding desired two
internal readings are entered directly.
•
Rate A, B
determines rate independently for Channel A (Item #1) and Channel B (Item #2).
Either item can be selected for the analog output.
•
Rate A Only
determines rate only for Channel A. Channel B is not used.
•
Rate A, A Total
(Extended main board) determines Rate for Channel A (Item #1) and Total
for Channel A (Item #2) since last reset. Total can count down from an offset by entering a
negative scale factor.
•
Rates A+B, A-B, AxB, A-B, A/B, A/B-1
(Extended main board) can output arithmetic combi-
nations of Rates A and B (Item #1), Rate A (Item #2), or Rate B (Item #3). With rates A and
B scaled to produce a ratio close to 1 and an offset of -1, the special combination A/B-1,
called “Draw,” can output percentage changes, such as elongation of material as it passes
between rollers.
Applicable to all rate & frequency application examples:
Connect your transmitter to a PC running Instrument Setup (IS) Software. Establish commu-
nications. To open a setup file for editing, click on “Get Setup” under the Counter tab to retrieve
the latest setup file from your transmitter, or click on “Open Setup” under the File tab to retrieve
a previously saved setup file from disk.
Relay Alarms and Analog Out respond to the counts that are transmitted digitally. While a
decimal point can be specified and will be transmitted digitally, it does not affect counts (except
for power factor). For example, the same 58134 count frequency can be transmitted as 58134
Hz or 58.134 kHz
Following editing, click on the Main Menu button. Under the Counter tab, click on “Put Setup”
to download your setup file into your transmitter. Under the File tab, click on “Save Setup As”
to save your setup to disk if desired.