69
changed by pressing the
Up
or
Down
buttons.
When this digit is correct pressing
P
will transfer
control to the next digit.
To position the decimal point in the scale factor,
move the flashing digit to the left hand side of the
required decimal point position and
simultaneously press the
Up
and
Down
buttons.
When the required scale factor has been entered,
press
E t
o store the number and return to the
main menu.
4.5.7 Timebase: ‘t-bASE’
This function multiplies the speed display by 1,
60 or 3,600 to show revolutions per second,
minute or hour.
To check or change the timebase, select 't-bASE'
from the main menu and press
P
which will
reveal the current setting. Pressing the
Up
or
Down
button will scroll through the three options:
Display
Units
tb-1
for speed / second
tb-60
for speed / minute
tb-3600
for speed / hour
When the required timebase is displayed press
E
to enter the selection and return to the main
menu.
4.5.8 Display filter: ‘FILtEr’
This digital filter has two independent adjustable
parameters enabling the speed display frequency
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 as shown below.
First digit
Filter time constant
seconds
0X
0
1X
1.3
2X
4.3
3X
6.5
4X
8.7
5X
11.3
6X
15.7
7X
20.9
8X
25.2
9X
31.5
The second digit defines the deviation from the
displayed rate at which the filter will be
overridden and the speed display will move
rapidly to the new value.
Second
digit
Magnitude of step
change which will
produce a rapid
response
X0
Off
X1
1%
X2
2%
X3
4%
X4
8%
X5
12%
X6
16%
X7
24%
X8
32%
X9
64%
By careful adjustment of the two parameters a
stable display with an acceptable step input
response can be obtained for most applications.
During commissioning it is recommend that
initially the second digit is set to 0 (off) and the
first digit is adjusted to provide acceptable speed
display stability. The second digit should then be
increased until the selected step size is greater
than the noise on the speed signal, at which
setting the speed display will again become
stable. These will be the optimum filter
parameters for acceptable speed display stability
and a fast response to a large speed signal
change.
To check or change the filter select 'FILtEr' from
the main menu and press
P
to reveal the current
settings. Pressing the
Up
or
Down
button will
change the flashing digit and
P
will transfer
control to the second digit. While making
adjustments the filtered speed display is shown
on the lower display so that stability can be
assessed. When set as required, press the
E
button to enter the revised parameters and return
to the main menu.
4.5.9 Clip off: ‘CLIP-OFF’
Clip off defines the speed threshold above which
the monitored machine is assumed to be working
and the run-time clock is activated.
To check or change the clip-off threshold select
'CLIP-OFF' from the main menu and press
P
which will reveal the current setting. The
threshold is shown in the units already selected
for the speed display. One digit will be flashing.
The value of the flashing digit may be changed
by pressing the
Up
or
Down
buttons. When this
digit is correct pressing
P
will transfer control to
the next digit. When clip-off is set as required,
press the
E
button to enter the revised figure and
return to the main programme menu.
When the displayed speed falls below the
entered threshold, the speed display will show
