76
4.8
CALIBRATION EXAMPLE
A BA364D is required to display the speed of a
rotating shaft in revolutions per minute with a
resolution of 1rpm. The speed sensor is a
magnetic pick-off that produces four voltage
pulses per revolution. A run-time display is
required, which is to operate when the speed
exceeds 5rpm and is to be resettable from the
BA364D front panel. To prevent tampering the
instrument programme menu is to be protected
by security code 1209
The BA364D may be calibrated on-site without
disconnection from the power supply or from the
magnetic pick-off.
Step 1
Enter the programming mode
Put the BA364D in the programming
mode by simultaneously pressing
P
and
E.
Assuming a security code has
not already been entered the
instrument will respond by displaying
‘FunctIon’ which is the first parameter
in the main menu. See Fig 4.3
Step 2
Select the instrument function
With ‘FunctIon’ displayed, press
P
to
reveal the existing instrument
function. If this is not ‘tACHO’, select
‘tACHO’ using the
Up
or
Down
button.
To prevent accidental changes the
new setting will only be executed after
the pass word ‘SurE’ has been
entered.
Press
P
which will produce a display
of ‘Set nO’ with the ‘nO’ flashing.
Using the
uP
or
Down
button change
‘nO’ to ‘YES’ and press
P
again which
will result in a display of ‘0000’. Using
the
Up
or
Down
button to adjust each
digit and the
P
push-button to transfer
control to the next digit, enter the
pass word SurE.
Note:
S is entered
as 5.
Finally, press
E
which will execute the
function change and return the
instrument to the ‘FunctIon’ prompt in
the main menu.
Step 3
Select the type of input
Using the
Up
or
Down
button scroll
through the main menu until ‘InPut’ is
displayed; press
P
to reveal the
existing setting. Using the
Up
or
Down
buttons select ‘COIL’, the input
for a magnetic pick-off, and then
return to the 'InPut' prompt in the
main menu by pressing
E
.
Step 4
Position of decimal point
In this example the BA364D is
displaying rotary speed and no
display decimal point is required.
Select ‘d.P.’ from the main menu and
press
P
. The display will be activated
with one digit plus the following
decimal point flashing. Press the
Up
or
Down
button until the least
significant digit (right hand digit) is
flashing which will result in no decimal
point being displayed.
Finally press
E
to return to the 'd.P’.
prompt in the main menu.
Step 5
Enter the rotational scaling factor
In this example the magnetic pick-off
produces four voltage pulses per
revolution, the instrument rotational
scaling factor must therefore be set to
4.0
Select ‘r SCALE’ from the main menu
and press
P
which will show the
current figure with one digit flashing.
To position the decimal point, operate
the
P
push-button to move the
flashing digit to the second least
significant digit. Pressing the
Up
and
Down
buttons simultaneously will then
fix the decimal point in front of the
least significant digit.
Using the
Up
and
Down
buttons to
adjust each digit in turn and the
P
button to transfer control between
digits, enter 4.0 Finally return to the
'r SCALE' prompt in the main menu
by pressing
E
.
Step 6
Set the display timebase
Select ‘t-bASE’ from the main menu
and press
P
to show the current
setting. In this example rotary speed
is required in revolutions per minute.
Using the
Up
or
Down
button scroll
through the three options and select
‘tb-60’ which will multiply the rate
display by 60 to provide a display in
revolutions per minute (rpm). Return
to the ‘t-bASE’ prompt in the main
menu by pressing
E
.
