20
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 Totalier’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 BA334NG 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.
Summary of Contents for BA334NG
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