BEKA BA364E, Руководство пользователя

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6.4 Input A:
inPut-A
The Input A function contains two sub-functions
inP . tYPE
and
dEbounCE
that define the type of input
and the amount of input noise rejection.
6.5 Input A type:
inP. tYPE
inP . tYPE
is a sub-menu in the
inPut-A
function
which defines the type of input sensor or input pulse
that the instrument will count at Input-A. To check or
change the type of input, select
inPut-A
in the
configuration menu and press
(
which will reveal
the
inP. tYPE
prompt, pressing
(
again will show the
existing Input-A setting . If set as required press
)
twice to return to the configuration menu, or
repeatedly press the
&
or
*
button until the
required type of input is displayed and then press
)
twice to return to the configuration menu.
One of following six types of input may be selected:
Switching
thresholds
Low High
oP . CoL
Open collector 2 2 10k Ω
VoLt5L
Voltage pulse low 1 1 3V
VoLt5H
Voltage pulse high 1 3 10V
CoiL
Magnetic pick-off 0 40mV
Pr . dEt
Proximity detector 2 1.2 2.1mA
ContACt
Switch contact 2 100 1000 Ω
Notes:
1. Maximum voltage input +28V.
2. For sensors connected to Input-A that require
energising i.e. proximity detectors, switch
contacts or open collector sensors, terminals 3
& 4 of the BA364G should be linked together.
3. To count correctly, the input pulse must fall
below the lower switching threshold and rise
above the higher switching threshold.
4. See section 6.6 for typical maximum counting
frequency.
6.6 Input A debounce:
dEbouncE
dEbouncE
is an adjustable sub-menu in both the
inPut-A
and
inPut-b
functions which prevents the
input miscounting when the input pulse has noisy
edges, such as those resulting from a mechanical
contact closing and bouncing.
The debounce
function only applies to the input in which the
function is located.
Three levels of protection may be independently
selected for each input. The amount of debounce
applied depends upon the type of Counter input that
has been selected for the input in the associated
inP .
tYPE
function.
Select
inPut-A
or
inPut-b
in the configuration menu
and press
(
which will reveal the
inP . tYPE
prompt,
press the
&
or
*
button to select
dEbouncE
followed by
(
to reveal the existing setting.
Pressing the
&
or
*
button will scroll through the
three levels. When the required level has been
selected, pressing
)
twice will enter the selection
and return the display to the configuration menu.
The following table shows the minimum time that the
input pulse must be continuously above the upper
input switching threshold and continuously below the
lower switching threshold to ensure that the Counter
processes the input pulse.
Input switching
thresholds are shown in section 4.1.2.
debounce
level
Min input pulse width
Type of Input
Contact All others
Default 1600µs 40µs
Heavy 3200µs 350µs
Light 400µs 5µs
The maximum counting frequency of the BA364G
depends upon the debounce level selected, the
shape of the input pulse and its amplitude. The
following table assumes a square wave input and is
included for guidance.
The maximum counting
frequency will be lower if the input pulses have
sloping edges and the pulse amplitude only slightly
exceeds the input switching thresholds.
ONLY FOR GUIDANCE
debounce
level
Max counting frequency
Type of input
Contact All others
Default 250Hz 12kHz
Heavy 120Hz 2kHz
Light 1000Hz 100kHz
Minimum input counting frequency is 0.01Hz. Below
this frequency the rate display will be forced to zero.
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