BEKA BA337E, Руководство пользователя

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6.7 Debounce:
dEbouncE
dEbouncE
is an adjustable sub-menu in the
inPut
function which prevents the Rate Totaliser
miscounting when the input pulse has noisy edges,
such as those resulting from a mechanical contact
closing and bouncing.
Three levels of protection
may be selected and the amount of debounce applied
depends upon the type of Rate Totaliser input that has
been selected in the
inP . tYPE
function.
The following table shows the minimum time that the
input pulse must be continuously above the upper
input switching threshold and continuously below the
lower switching threshold to ensure that the Rate
Totaliser processes the input pulse. Input switching
thresholds are shown in section 4.1.2.
De-bounce
level
Min input pulse width
Type of Input
Contact All others
Default
1600µs 40µs
Heavy
3200µs 350µs
Light
400µs 5µs
The Rate Totaliser’s maximum counting frequency
depends upon the debounce level selected, the shape
of the input pulse and its amplitude. The following
table assumes a square wave input and is only for
guidance. The maximum counting frequency will be
lower if the input pulses have sloping edges and the
pulse amplitude only slightly exceeds the input
switching thresholds.
ONLY FOR GUIDANCE
De-bounce
level
Max counting frequency
Type of input
Contact All others
Default
250Hz 12kHz
Heavy
120Hz 2kHz
Light
1000Hz 100kHz
The minimum input frequency is 0.01Hz. Below this
frequency the rate display will be forced to zero.
The
dEbouncE
function is a sub-menu located in the
inPut
function. Select
inPut
in the configuration
menu and press
(
which will reveal the
inP . tYPE
prompt, press the
&
or
*
button to select
dEbouncE
followed by
(
to reveal the existing setting.
Pressing the
&
or
*
button will scroll through the
three levels. When the required level has been
selected, pressing
)
twice will enter the selection
and return the display to the
inPut
prompt in the
configuration menu.
6.8 Display update interval:
uPdAtE
If either the rate or the total display is likely to
change rapidly, a longer interval between display
updates may simplify reading the Rate Totaliser
display. This function allows one of six different
display intervals between 0.5 and 5 seconds to be
selected. The selected display update interval does
not affect the update time of any other instrument
function.
To adjust the update interval select
uPdAtE
from the
configuration menu and press
(
to reveal the
existing time. Pressing the
&
or
*
button will
scroll through the six times. When the required
interval has been selected press
)
to enter the
selection and return to the configuration menu.
6.9 Upper display:
di5P-1
Usually total flow is shown on the larger upper eight
digit display, but this function allows rate to be
shown on the upper display and total on the smaller
lower display which can show six positive digits.
To check the status of the upper display, select
dI5P-1
from the configuration menu and press
(
which will reveal if the display is showing
rAtE
or
totAL
. The setting can be changed by pressing the
&
or
*
button followed by the
)
button to enter
the selection and return to the configuration menu.
6.10 Lower display:
di5P-2
This function turns the lower display
on
or
off.
When
turned
off
, the BA337E or the BA338E will only have
one eight digit display which may be configured in
the
di5P-1
function to show total flow or rate of flow.
To check the status of the lower display, select
di5P-2
from the configuration menu and press
(
to
reveal if the lower display is
on
or
oFF
. The setting
may be changed by pressing the
&
or
*
button
followed by the
)
button to enter the selection and
return to the configuration menu.
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