BEKA BA384E, Manual

Page: 40 / 68

40
Finally, enter the new figure and return to
the
FACtor-A
prompt in the configuration
menu by pressing
)
. The output from
FACtor-A will now be in litres which may
be scaled to produce required rate and
total displays.
Repeat for input b using the
FACtor-b
function.
See 6.13
Step 10 Enter the total scale factor
The Total Scale Factor
5CALE . t-A
is a
dividing factor adjustable between
0.0001 and 99999 that enables total flow
to be displayed in the required
engineering units. In this example the
total flow display is required in cubic
metres. There are 1,000 litres in a cubic
metre so
5CALE . t-A
should be set to
1000
.
Using the
&
or
*
push button select
5CALE . t-A
from the configuration menu
and press
(
to reveal the existing value
with one digit flashing. This should be
changed to
1000
using the
&
or
*
push button to adjust the flashing digit
and the
(
button to transfer control to
the next digit and to position the decimal
point. Finally, enter the new value and
return to the
5CALE . T-A
prompt in the
configuration menu by pressing
)
.
The total flow display is independent of
the rate display.
Repeat for input b using the
5CALE . t-b
function.
See 6.14
Step 11 Enter the rate scale factor
5CALE . r-A
is a dividing factor adjustable
between 0.0001 and 99999 that enables
the input A flow rate to be displayed in
the required engineering units. The rate
display timebase is determined by
‘
t-bA5E
that is adjusted in Step 12.
In this example the rate of flow display is
required in imperial gallons.
FACtor-A
,
which was adjusted in Step 8, has an
output in Litres that must be converted to
imperial gallons. There are 4.5461
Litres in an imperial gallon therefore
5CALE . r-A
should be adjusted to 4.5461
Using the
&
or
*
push button select
5CALE . r-A
from the configuration menu
and press
(
to reveal the existing value
with one digit flashing.
This should be changed to 4.5461 using
the
&
or
*
push button to adjust the
flashing digit and the
(
button to
transfer control to the next digit and to
position the decimal point. Finally, enter
the new value and return to the
5CALE . r-A
prompt in the configuration
menu by pressing
)
.
The flow rate display is independent of
the total flow display.
Repeat for input b using the
5CALE . r-b
function.
See 6.15
Step 12 Enter the rate timebase
The rate timebase determines if rate is
displayed per second, per minute or per
hour. In this example gallons per hour
are required. Using the
&
or
*
push
button select
t-bA5E
from the
configuration menu and press
(
. Again
using the
&
or
*
push button select
tb-3600
from the three options which will
multiply the rate display by 3600. Enter
the selection and return to the
t-bA5E
prompt in the configuration menu by
pressing
)
.
See 6.16
Step 13 Adjust the display filter
The digital display filter has two
independent adjustable parameters
enabling the rate display response to be
tailored for optimum performance. The
filter parameters are controlled by a two
digit number. The first digit defines the
amount of filtering applied to the display,
for initial configuration it is recommended
it is set to 2 which is a time constant of
4.3 seconds. The second digit controls
jump-out following a step input change
and it is recommended that this is initially
set to 0.
After configuration during commissioning
both parameters should be adjusted
experimentally to provide a stable display
with an acceptable step response. To
allow the effect of filter changes to be
seen immediately, the live rate display is
shown on the lower display while the
filter parameters are shown and may be
adjusted on the upper display.