27
During commissioning it is recommend that initially
the second digit is set to
0
(off) and the first digit is
adjusted to provide acceptable rate display stability.
The second digit should then be increased until the
selected step size is greater than the noise on the
display signal, at which setting the rate display will
become stable. These will be the optimum filter
parameters for acceptable rate display stability and
a fast response to a large rapid flow rate change.
To check or change the filter select
FiLtEr-A
in the
configuration menu and press
(
which will reveal
the current settings with the first digit flashing.
Pressing the
&
or
*
button will change the
flashing digit and
(
will transfer control to the
second digit. While making adjustments the filtered
rate display is shown on the lower display so that
stability can be assessed while adjustments are
being made. When set as required, press the
)
button to enter the revised parameters and return to
the
FiLtEr-A
prompt in the configuration menu.
6.18 Clip-off*:
CLP
.
oFF-A
To prevent totalisation of very low flow rates that
over long periods may result in significant
totalisation errors, the BA384NG may be configured
to stop totalising when the flow rate falls below an
adjustable threshold.
To check or change the clip-off threshold select
CLP
.
oFF-A
from the configuration menu and press
(
which will reveal the existing setting. The
threshold is shown in the units already selected for
the flow rate display. One digit will be flashing. The
value of the flashing digit may be changed by
pressing the
&
or
*
button. When this digit is
correct, pressing
(
will transfer control to the next
digit. When clip-off is set as required, press the
)
button to enter the revised figure and return to
the
CLP
.
oFF-A
prompt in the configuration menu.
When the Input-A flow rate falls below the clip-off
threshold, the rate display will show zero flow,
totalisation will stop and the
HOLD
annunciator will be
activated. The flow indicator will continue to rotate
for 2 seconds each time an input pulse is received
i.e. at input pulse frequencies above 0.5Hz it will
appear to rotate continuously.
Note:
To avoid confusion, when
FACtor-A
,
5CALE
.
r-A
,
t-bA5E
, or the position of the
rate display decimal point are changed, clip-
off will automatically be reset to zero. A new
clip-off threshold must be entered after
changes to any of these functions have
been made.
6.19 Local reset:
LoC clr
The Local reset function contains two sub-functions
clr tot
and
clr gtot
which when enabled allow
each input total and the grand total to be reset to
zero via the instrument push buttons while the Rate
Totaliser is in the totalising mode.
6.20 Local total reset:
clr tot
clr tot
is a sub-menu in the
loc clr
function which
when activated allows an operator to reset total A,
total b or both totals and any stored pulses in the
pulse output by operating the
&
and
*
push
buttons simultaneously for more than three seconds
while the BA384NG is in the totalising mode.
To check or change the function select
loc clr
in
the configuration menu and press
(
which will
reveal the
clr tot
prompt, operate
(
again to
show if the local total reset is
on
or
oFF
. If set as
required operate the
)
button twice to return to the
configuration menu, or the
&
or
*
button to
change the setting followed by the
)
button twice
to enter the change and return to the
loc clr
prompt
in the configuration menu.
Note:
The total display may also be reset to zero
remotely by connecting terminals RS1 and
RS2 together for more than one second.
See sections 3.7; 4.3 and 6.22 of this
manual.
6.21 Local grand total reset:
clr gtot
The grand total is a separate sixteen digit counter
which is incremented in parallel with the composite
total input A+b or input A-b, but is not zeroed when
any of the displayed totals are reset to zero. The
grand total may be viewed in the totalising mode in
two eight digit sections as described in section 2.2 of
this manual.
Clr gtot
is a sub-menu in the
loc clr
function
which when activated allows the operator to reset
the grand total display to zero with the BA384NG in
the totalising mode by operating the
)
and
*
push buttons simultaneously for more than ten
seconds.
To check or change the local grand total reset select
loc clr
in the configuration menu and press
(
which will reveal
clr tot
. Using the
&
or
*
button select
clr gtot
and press
(
which will show
if the local grand total reset function is
on
or
oFF
. If
set as required operate the
)
button twice to return
to the configuration menu, or the
&
or
*
button to
change the setting followed by the
)
button twice
to enter the change and return to the
loc clr
prompt
in the configuration menu.
