BEKA BA654D, Руководство пользователя

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3.1.1 Power supply failure
If the power supply for the BA654D fails during
a batch, the instrument will remember the
amount of product dispensed when the supply
failed, together with the number of cycle
completed if autostart is being used. When
power is restored, the batch controller will
return in the Paused condition displaying the
amount of product dispensed prior to the
failure. Operating the Start pushbutton will
complete the batch.
If the supply failure occurs when the batch
controller is in the Ready or Complete state,
the controller will return in the same state when
power is restored.
3.2 Pulse inputs
As shown in Fig 3 the BA654D batch controller
may be connected to a wide variety of pulse
transducers and sources. Input 1 is for pulse
sources that need powering by the batch
controller such as switch contacts or a 2-wire
proximity detector. Input 2 is for voltage pulse
inputs such as the magnetic pickup in a turbine
flowmeter, or a voltage pulse output from a
flowmeter.
The following table shows the switching
thresholds for the various transducers, plus the
maximum operating frequency and the input
terminal numbers. For reliable counting the
input signal must fall below the lower switching
threshold and rise above the upper threshold.
Switching
thresholds
Freq
max
Input
terminals
Switch 100
Ω
1000
Ω
100Hz 12 & 11 +
Proximity
detector
1.2m
A
2.1mA 5 kHz 12 & 11 +
Open
collector
2k
Ω
10k
Ω
5kHz 12 & 11 +
Magnetic
pickup
10m
V
30mV 5kHz 16 & 15 +
Low
voltage
pulse
1V 3V 5kHz 16 & 14 +
High
voltage
pulse
3V 10V 5kHz 16 & 13 +
Note: Only one input may be used at a time.
3.2.1 Switch contact input
Any switch contact may be connected directly
to terminals 12 & 11. Most magnetically
activated reed relays used in turbine
flowmeters may be used.
The maximum operating frequency for a switch
contact input is 100Hz.
3.2.2 2-wire proximity detector input
Any 2-wire proximity detector complying with
NAMUR switching thresholds (1.2mA and
2.1mA) may be connected to terminals 12 and
11.
When programmed to operate with a proximity
detector, the maximum input frequency of the
BA654D batch controller is 5kHz.
3.2.3 Voltage pulse input
Voltage pulse sources may be connected
directly to input 2, the terminals used depend
upon the input magnitude – see the table in
section 3.2.
This enables the BA654D to be connected
directly to most flowmeters incorporating a
magnetic pickup, or an amplifier producing a
high level pulse output.
When conditioned to operate with a voltage
pulse source, the maximum input frequency of
the BA654D batch controller is 5kHz.
3.3 4/20mA analogue input
The BA654D can also accept an analogue
4/20mA input representing rate of flow from a
current source,
not a current sink . Loop
powered flow transmitters require an additional
power supply. The batch controller input is
galvanically isolated and only introduces a
0.6V drop into the 4/20mA loop. It may
therefore be connected into to almost any
flowmeter loop.
Voltage
drop
Freq.
Max.
Input
terminals
4/20mA 0.6V 2Hz 16 & 17+
3.4 Switch outputs
The BA654D batch controller has three single
pole relay outputs which may be used for
switching valves, actuators or contactors.
Output Terminals
Control 1 A1 & A2
Output 2
May be configured
to output one of six
different signals.
A3 & A4
Output 3
May be configured
to output one of six
different signals.
A5 & A6