3. SYSTEM DESIGN
Fig 2 illustrates the basic circuit that is used for all
BA567E-SS Counter installations. For simplicity,
connections for the optional alarms, pulse output
and 4/20mA output are shown separately in section
8 this manual.
Fig 2 BA567E-SS connections
When designing a system it is important to
remember that terminals 2, 6 and RS2 are
interconnected within the BA567E-SS see Fig 1.
3.1 Power supply
The BA567E-SS Counter requires a 10 to 30V dc
supply between terminal 1 & 2 and consumes:
10mA without optional backlight
plus 6mA when terminals 3 & 4 are linked
plus 22mA for optional backlight
3.2 Pulse input
As shown in Fig 2 the BA567E-SS can count pulses
from a wide variety of sensors.
The following table shows the switching thresholds
for the various types of sensor. For reliable
counting the pulse input must fall below the lower
threshold and rise above the upper threshold.
Input sensor
Switching thresholds
Lower Upper
Switch 1001000
Proximity detector 1.2mA 2.1mA
Open collector 2k10k
Magnetic pick-off 0mV 40mV peak
Voltage pulse low 1.0V 3.0V
Voltage pulse high 3.0V 10.0V
3.2.1 Switch contact input
Any switch contact may be directly connected to
pulse input terminals 5 and 6, The BA567E-SS
contains a configurable debounce circuit to prevent
contact bounce being counted. See section 5.6
including details of the maximum counting
frequency.
3.2.2 2-wire proximity detector input
Most NAMUR 2-wire proximity detector may be
directly connected to the BA567E-SS pulse input,
providing the minimum operating voltage of the
proximity detector is less than 7.5V. The BA367E-
SS contain a configurable debounce circuit to
prevent false triggering. Three levels of debounce
protection are independently available. See section
5.6.
3.2.3 Open collector input
Sensors with an open collector output may be
directly connected to Counter input terminals 5 & 6.
Polarity of the sensor output should be observed.
The BA567E-SS contains a configurable debounce
circuit to prevent false triggering. Three levels of de-
bounce protection are independently available. See
section 5.6.
3.2.4 Magnetic pick-off input
Sensors incorporating a magnetic pick-off will have a
low level voltage output unless the sensor
incorporates an amplifier. CoiL in the BA567E-SS
input configuration menu is a low level voltage pulse
input intended for use with a magnetic pick-off. The
Counter contains a configurable debounce circuit to
prevent false triggering of the instrument. See
section 5.6.
3.2.5 Voltage pulse input
Two voltage pulse input ranges are selectable in the
BA567E-SS Counter configuration menu, VoLt5 L
and VoLt5 H as shown in section 3.2. The Counter
contains a configurable debounce circuit to prevent
false triggering of the instrument. Three levels of de-
bounce protection are independently available. See
section 5.6.
3.3 Remote reset
The Counter's total display may be remotely reset to
zero by connecting terminals RS1 and RS2 together
for more than one second. Permanent
interconnection inhibits counting.
Note: The BA367E may also be configured to
reset the total display to zero by operating
the &and *push buttons simultaneously
for more than two seconds in the totalising
mode i.e. when the instrument is displaying
flow. See 5.19
5
