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2.9 CALIBRATION EXAMPLE
A BA364D is required to display the position and
speed, including direction, of a cable which is
sensed by two proximity detectors mounted on a
wheel with a circumference of 1m over which the
cable runs. The sensors, which produce fifteen
pulses per revolution, are positioned so their
outputs are electrically 90
o
apart. The BA364D
is required to display the position of the cable
relative to a starting point in metres with a
resolution of 0.1m, and to show speed of the
cable in metres per second with a resolution of
1m. The total display (position) is to be
resettable by an external contact, not 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
two proximity detectors.
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 2.3
Step 2
Select the instrument function
With ‘Function’ displayed, press
P
to
reveal the existing instrument
function. If this is not ‘CountEr’,
select ‘CountEr’ 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 inputs
Using the
Up
or
Down
button scroll
through the main menu until ‘InPut A’
is displayed; press
P
to reveal the
existing setting. Using the
Up
or
Down
buttons select ‘Pr.dEt’, the input
for a 2-wire proximity detctor, and
then return to the 'InPut' prompt in the
main menu by pressing
E
.
Repeat for the second input ‘InPut b’
Step 4
Select input count mode
The two proximity detectors are
positioned so their outputs are
electrically 90
o
apart. From this
information, in the quadrature input
mode the BA364D can sense the
direction of wheel rotation. Hence, the
relative position of the cable can be
displayed
Select ‘Count’ from the main menu
and press
P
. Using the
Up
or
Down
button select ‘A rEL b’ the quadrature
function and press
E
to return to the
‘Count’ prompt in the main menu.
Step 5
Counting edge
The proximity detector current rises
when it detects a marker on the
wheel. The BA364D is therefore
required to count when the proximity
detector current changes from low to
high i.e. a rising edge.
Select ‘Cnt EdGE’ from the main
menu and press
P
to show the
existing setting. Using the
Up
or
Down
button select '‘EdGE 2'’
followed by
E
to enter the selection
and return to the main menu.
Step 6
Activate lower rate display
A rate display is required so the lower
display must be activated.
Select ‘dISPLAY.2’ from the main
menu and press
P
to show the
existing setting. Using the
Up
or
Down
button select 'On’ followed by
E
to enter the selection and return to the
main menu.
Step 7
Position of decimal point
In this example the BA364D is
required to display total (position) with
a resolution of one decimal place and
rate (speed) with no decimal point.
Select ‘d.P.’ from the main menu and
press
P
. The display will be activated
