30
To achieve reliable counting from a quadrature
encoder the two input signals do not require
equal marks and spaces, but input A must not
change state for 100µS before or after input B as
shown in timing diagram below.
2.5.5 Counting edge ‘Cnt. EdGE’
This function allows the edge on which a count
occurs to be selected. It applies to input A for all
counting modes except quadrature (‘A rEL b’)
and to input B for all modes except for A
controlled by B (‘A Con b’).
To check or change the edge on which counting
occurs select 'Cnt EdGE' from the menu and
press
P
which will reveal ‘EdGE 1’ or ‘EdGE 2’. If
required press the
Up
or
Down
button to change
the setting, followed by the
E
button to return to
the main menu.
EdGE 1
Type of input Counting edge
Voltage
Low to high
Switch contact
Closed to open
Open collector
Closed to open
Proximity detector
High to low current
EdGE 2
Type of input Counting edge
Voltage
High to low
Switch contact
Open to closed
Open collector
Open to closed
Proximity detector
Low to high current
2.5.6 Position of the decimal point(s): ‘d.P.’
The BA364D total display has eight digits. The
decimal point may be positioned between any of
the seven least significant digits, or it may be
omitted.
To adjust the position of the decimal point select
'd.P.' from the main menu and press
P.
This will
activate the display with one digit plus the
following decimal point flashing. If only the least
significant digit is flashing the decimal point will
be omitted. The position of the decimal point can
be moved by pressing the
Up
or
Down
push-
button.
Similarly, a decimal point may be positioned
between any of the five least significant digits on
the lower rate display, or may be omitted.
Pressing the
P
push-button will transfer control to
the lower display.
When the decimal point(s) have been positioned
as required press
E
to return to the main menu.
Note:
It is only necessary to position the decimal
point in the lower display if it is activated (see
2.5.7), or a rate alarm or a 4/20mA rate output is
required.
2.5.7 Lower display: ‘dISPLAY.2’
This function turns the lower rate display on or
off. When turned off the BA364D will display just
the total number of pulses, when turned on it will
display the total number of pulses and the pulse
rate simultaneously. To check the status of the
lower display select 'dISPLAY.2' from the menu
and press
P
which will reveal if the function is
'On' or 'OFF'. If required press the
Up
or
Down
button to change the setting, followed by the
E
button to return to the main menu.
Note:
Providing the rate scale factor, timebase
and displayed decimal point have been
programmed, all the rate functions will operate
irrespective of whether the lower display is turned
on or off.
2.5.8 Total scale factor: ‘SCALE-t’
This factor defines the arithmetic relationship
between the number of input pulses and the total
display. SCALE-t is a dividing factor that may be
adjusted between 0.001 and 99999999.
e.g. If the counter is required to increment the
display one count when 120 pulses have been
received:
SCALE-t = Number of input pulses
Required display
= 120
1
SCALE-t = 120
To check or change the scale factor select
'SCALE-t' from the main menu and press
P
to
reveal the existing setting, one digit will be
flashing. The value of the flashing digit can be
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 scaling 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 total scale factor has been
entered, press
E t
o return to the main menu.
