BEKA BA550 Series User manual

Issue 14
25th April 2000
BA550P and BA550C
Batch Controllers
The BA550P and BA550C are CE marked to show compliance with EMC Directive 98/336/EEC

1How to use this manual
2Description
3Operation
4Operating a BA550P or BA550C
4.1 Initialisation sequence
4.2 Operation as a batch controller
4.2.1 Adjusting the batch setpoint
4.3 Operation as a totaliser
5 System design
5.1 BA550P pulse input
5.1.1 2-wire proximity detector input
5.1.2 Voltage free contact input
5.1.3 Voltage pulse input
5.2 BA550C 4/20mA analogue input
5.3 Output control relays
5.4 Auxiliary outputs
5.4.1 Retransmitted pulse
5.4.2 Reset status
5.4.3 Flow alarm
5.5 Remote switches
5.6 Power supply
6 Installation
6.1 Location
6.2 Input conditioning
6.2.1 BA550P (pulse input)
6.2.2 BA550C (4/20mA input)
6.3 Installation procedure
7 Programming
7.1 Security
7.2 Programming structure
7.3 Programming the mode settings
7.3.1 Function of BA550
7.3.2 Local or remote control
7.3.3 Retransmitted output
7.3.4 Square root extraction
7.3.5 Missing pulse detection
7.3.6 Missing pulse detection delay
7.3.7 Serial communications
7.3.8 Direction of count
7.3.9 Automatic reset
7.3.10 Automatic restart
7.3.11 Overrun compensation
7.3.12 Test routine
7.3.13 Language
7.4 Programming the batch parameters
7.4.1 Batch setpoint
7.4.2 Setpoint limit
7.4.3 Start delay time for output 2
7.4.4 Stop delay count for output 2
7.4.5 Grand total
7.4.6 Decimal point
7.4.7 Batch scale factor
7.5 Programming the rate parameters
7.5.1 Decimal point
7.5.2 Rate scale factor
7.5.3 Display timebase
7.5.4 Rate display filter
8 Applications
8.1 Use as a totaliser and rate indicator
8.2 Use as a batch controller
9 Maintenance
10 Accessories
10.1 Scale card
10.2 Tag plate
11 Customer Comments
Illustrations
Fig. 1 Simplified block diagram
Fig. 2 Example of 2 stage batch control
Fig. 3 Alternative pulse inputs
Fig. 4 Auxiliary outputs
Fig. 5 Remote switches
Fig. 6 Input conditioning BA550P
Fig. 7 Panel cut-out dimensions
Fig. 8 Terminal connections
Fig. 9 Programming structure
Fig. 10 Mode parameter menu
Fig. 11 Batch parameter menu
Fig. 12 Rate parameter menu
Fig. 13 BA550P used as a totaliser
Fig. 14 BA550C used as a totaliser
Fig. 15 BA550P used as a batch controller
CONTENTS

1. HOW TO USE THIS MANUAL
This instruction manual has been written so that
the reader can quickly obtain the information he
or she requires without having to read
unnecessary sections. However, we
recommend that whatever your interest you read
sections 2 and 3, Description and Operation
followed by the sections covering your particular
requirements.
2. DESCRIPTION
The BA550 enables batch control of liquids,
solids or components to be performed simply
and economically. Although incorporating
sophisticated features the instrument is very
easy to use and can operate as a stand-alone
controller, or form part of a more complex control
system. Two independent output relays may be
programmed for one or two stage control which,
together with automatic overrun compensation,
minimises batching errors caused by actuator
delays.
Front panel push-buttons enable the operator to
start and stop the batch, adjust the batch setpoint
and to select one of four different operating
displays: current batch total, input rate, batch
setpoint or grand total. The display may be in
any engineering units and the input rate can be
shown per second, minute or hour. A light
emitting diode (LED) above each front panel
push-button clearly indicates which display has
been selected. For applications where large or
remote push-buttons are required, control may
be transferred to external switches with or
without the front panel push-buttons inhibited.
Two alternative versions of the BA550 batch
controller are available. For pulse signals the
BA550P accepts inputs from a wide range of
transducers including 2-wire proximity detectors,
switch contacts, open-collector transistors or any
device with a voltage pulse output. The
BA550C has a galvanically isolated analogue
input which may be connected in series with any
4/20mA linear or square law current loop.
Both versions of the BA550 may also be used for
totalising and rate indicating applications. To
simplify operation for totalising applications, all
the batch control functions may be inhibited by
one programme command.
Adjustment of the batch setpoint and
programming of all functions is performed via the
five front panel push-buttons. To prevent
accidental or unauthorised adjustments three
levels of access are defined by the position of
two security links connected between terminals
at the rear of the instrument. These links may be
hard-wired, or connected to a panel mounting
key switch when frequent changes are required.
A Light emitting diode (LED) on the front panel
indicates when the batch controller is in the
programme mode, and the display has helpful
plain language menus which guide the user
through the selection procedure.
An optional plug-in RS232 serial communication
board enables the BA550 to be interrogated and
controlled remotely, and thus to be integrated
with supervisory computers.
For hazardous area applications the
complementary intrinsically safe BA350BP and
BA350BC batch controllers are available.
3. OPERATION
Basically the BA550 batch controller is a digital
counter which switches two output relays on and
off at pre-set numbers. Fig 1 shows a simplified
block diagram of the instrument and illustrates
some of the additional features.
The BA550P incorporates programmable input
scaling to convert input pulses into meaningful
engineering units. For example, a controller
connected to a turbine flowmeter producing 107
pulses per litre may be programmed to display
this signal in litres, gallons or any other units by
selecting the appropriate scale factor. Similarly,
the rate parameters, which are totally
independent, may be programmed to display the
flowrate in litres, gallons or any other units per
second, minute or hour.
The BA550C incorporates similar scaling
functions which enable a 4/20mA analogue
signal to be displayed in engineering units.
The batch controller has two independent output
relays: Output 1 and Output 2. Output 1 is
energised immediately the Start push-button on
the controller is operated, followed by Output 2
after a programmable time delay. Towards the
end of the batch, Output 2 is de-energised a
programmable number of counts before the
batch setpoint is reached, when Output 1 is also
de-energised. Fig 2 illustrates a typical
application of two stage control. By operating a
small bypass valve from Output 1, and the main
control valve from Output 2 the flow can be
started and stopped slowly which will reduce
batching errors and flow surges.
1

With the batch control functions disabled the
BA550 becomes a very flexible totaliser and rate
indicator which can be used in many
applications, including the integration of a
4/20mA flow signal to calculate and display total
flow.
4. OPERATING A BA550P or BA550C
This section is primarily intended for users who
wish to operate a BA550P (pulse input) or a
BA550C (4/20mA input) instrument after it has
already been installed, programmed and
conditioned.
4.1 Initialisation
Each time a BA550 is connected to a power
supply it goes though an initialisation sequence
which briefly displays 8.8.8.8.8.8.8.8 and
illuminates the eight front panel LED indicators.
The instrument then enters the operating mode
in the stop state.
4.2 Operation as a batch controller
The BA550 is operated via five front panel
push-buttons, each of which has a single function
in the operating mode shown in bold black letters
on the front panel. Operation of any push-button
is acknowledged by a red light emitting diode
(LED) located immediately above the button.
Three additional red LEDs show the status of the
two control output relays and indicate when the
controller is in the programme mode.
Throughout this manual push-buttons and front
panel LEDs are shown in italics eg. Batch
push-button and STOP LED. Legends displayed
by the BA550 are shown within inverted commas
eg. 'CLEAR' and 'DELAY'.
The function of the push-buttons are:
Start Causes one or both of the outputs to
be energised which will start the
batch. The Start LED will remain
illuminated until the batch is fin-
ished, or the STOP push-button is
operated. If a start delay has been
programmed, Output 1 will be ener-
gised immediately the Start button
is pushed, followed by Output 2 af-
ter the start delay time.
STOP Operating this button during a batch
immediately de-energises both Out-
put 1 and Output 2 relays causing
the batch to pause. During a pause
any input signal continues to be
counted, the Start LED is extin-
guished and the Stop LED flashes
to indicate that the batch is not
complete.
The batch may be resumed at any
time by pressing the Start button. If
a start delay has been programmed,
Output 1 will be energised immedi-
ately the Start button is pushed, fol-
lowed by Output 2 after the start
delay time. At the end of each
batch Output 1 and Output 2 relays
will be de-energised, the Start LED
extinguished and the STOP LED
continuously illuminated.
Special case: When overrun compensation is
enabled, Output 1 is de-energised before the
batch setpoint is reached to compensate for
measured delays in the process. If a pause is
initiated by pressing the STOP button close to
the end of the batch, and process delays cause
the calculated setpoint to be exceeded, pressing
the Start button will not resume the batch.
Reset After completion of a batch the dis-
play must be reset before the next
batch can be started, unless auto-
matic reset or restart have been se-
lected - see note at the end of this
section. The display may also be
reset following an operator initiated
pause resulting from the STOP but-
ton being operated during a batch.
After resetting the display the Reset
and the STOP LEDs are continu-
ously illuminated. Whilst reset the
batch controller ignores input sig-
nals until the Start button is pressed
to initiate the next batch.
Batch This button has two functions: when
pressed and held the display initially
shows the programmed batch set-
point for three seconds, followed by
the grand total.
Rate This button toggles the display be-
tween the current batch total and
the current input rate. The LED
above the button is illuminated
when rate is being displayed.
2

Two software selectable options modify the
function of these push-buttons:
Automatic reset eliminates the need to
manually reset the BA550 at the end of each
batch. The Stop LED is illuminated at the end
of the batch and it is only necessary to press
the Start button to initiate the next batch - see
section 7.3.9
Automatic restart on completion of a batch
and following a programmable time delay, the
display is reset and the next batch started
automatically. This sequence continues until
the STOP button is operated - see section
7.5.10
4.2.1 Adjusting the batch setpoint
The batch setpoint can only be adjusted when
level 2 or 3 access has been selected - see
section 7.1
To prevent accidental selection of a dangerously
high setpoint, a programmable setpoint limit 'SP
LIMIT' is included above which the batch setpoint
can not be adjusted - see section 7.4.2. When
the batch parameter menu is selected, 'SP
LIMIT' will be displayed first if the setpoint limit is
off. The BA550 may be operated without a
setpoint limit, or a limit may be entered prior to
entering the batch setpoint.
To select the batch parameter programme menu
press the Prog and Batch push-buttons
simultaneously until the display shows
'SETPOINT' and the Prog and Batch LEDs are
illuminated. If 'SP LIMIT' is displayed first, which
indicates that the setpoint limit is off, press the
Up push-button until 'SETPOINT' is displayed.
The BA550 is now in the batch parameter
programme menu and the white legends show
the function of the front panel push-buttons.
Press Ent and the existing batch setpoint will be
displayed with the most significant left hand digit
flashing to show that this may be adjusted by
pressing the Up or Down button. When set to
the required figure, or if no adjustment of this
digit is required, press Ent to move to the next
digit. Adjust each digit in turn until all have been
set to the required figures and then return to the
operating mode by pressing Prog twice. Fig 11
shows this procedure diagrammatically.
4.3 Operation as a totaliser
Both versions of the BA550 may be used for
totalising and rate indicating applications when
the batch control functions are not required. To
simplify operation for these applications, the
batch control functions and the Start and STOP
push-buttons may be inhibited by one
programme command.
Operation of the Reset, Rate and Batch
push-buttons is acknowledged by a red light
emitting diode (LED) located immediately above
each button. An additional red LED indicates
when the instrument is in the programming
mode. The LEDs indicating the status of the two
output relays are inhibited.
When programmed as a totaliser the function of
the push-buttons are:
Start No function
STOP No function
Reset This push-button resets the display
to zero. The reset LED will remain
illuminated until the next input pulse
is received when totalising will begin
again. Operating the Reset button
does not reset the grand total. Input
pulses are ignored while the Reset
push-button is pressed.
Batch When pushed the display will show
'NO LIMIT' for approximately three
seconds followed by the grand total.
Rate This button toggles the display be-
tween the current total and the cur-
rent input rate. The LED above the
button is illuminated when the rate
is being displayed.
5. SYSTEM DESIGN
This section should be read before designing a
system incorporating a BA550. All the input and
output functions are described together with
examples of how the BA550 may be used to
control solids, fluids or components.
Two versions of the BA550 batch controller are
available. The BA550P accepts pulse signals
from a wide range of transducers including 2-wire
proximity detectors, switch contacts, open
-collector transistors or any device with a voltage
pulse output. The BA550C has a galvanically
isolated analogue input which may be connected
in series with any 4/20mA linear or square law
current signal. All other functions are the same
for both versions.
3

5.1 BA550P Pulse Input
The negative input terminal of the BA550P is
internally connected to the negative power
supply terminal see Fig 1. Although this is
irrelevant when the instrument is used with an
isolated transducer such as a proximity detector
or a voltage free switch contact, care must be
taken when connecting the BA550P to a voltage
pulse source. The negative side of the pulse
source must be at the same potential as the
negative side of the BA550 supply voltage.
5.1.1 Use with a 2-wire proximity detector
A 2-wire proximity detector is a solid state switch
which is activated when it comes close to a
target. Proximity detectors are available in many
shapes and sizes, but most conform to the
NAMUR electrical specification which defines the
output current in the activated and unactivated
conditions.
When correctly conditioned the BA550P batch
controller will count the output from any 2-wire
proximity detector which complies with the
NAMUR standard.
The output from open-collector transistors and
photo-transistors can also be counted by a
BA550P when conditioned to operate with a
proximity detector - see Fig 3. The transistor
must have an 'on' voltage of less than 2V, and
an 'off' leakage current of less than 1mA. These
requirements are not restrictive, unless the
transistor is fitted with protective diodes, and
allow the BA550P to work with a wide variety of
solid state detectors.
When conditioned for use with a 2-wire proximity
detector the maximum input frequency is 5kHz
.
5.1.2 Use with voltage free contacts
The number of times that a pair of voltage free
contacts opens may be counted by the batch
controller provided that the resistance of the
contacts when closed is less than 100 , and the
resistance when open is greater than 1,000 .
To eliminate multiple counting resulting from
contact bounce, the BA550 ignores inputs for
4ms after counting a contact opening. This limits
the maximum input frequency with voltage free
contacts to 100Hz.
When conditioned for use with switch contacts,
the BA550P has an open circuit input voltage
greater than 6V which will break down most
surface contaminating films.
5.1.3 Use with voltage pulses
The BA550P can be conditioned by two internal
plug-in links to accept low or high voltage input
pulses. Input switching thresholds are shown
below.
Input voltage thresholds Low High
For low voltage input 10mV 30mV
For high voltage input 1V 3V
The maximum permissible input voltage is 8V
when conditioned for a low voltage pulse input,
and 28V when conditioned for a high voltage
pulse input.
For voltage inputs the maximum input frequency
is 5kHz.
Note: The BA550P input terminals are not
galvanically isolated - see 5.1 and Fig 1.
5.2 BA550C 4/20mA analogue input
The BA550C has a galvanically isolated input
which may be connected in series with any
4/20mA linear or square law current loop. The
BA550C introduces an additional 0.75V drop into
the current loop. Providing this extra voltage is
available, the loop will not be affected.
5.3 Output control relays
The two output relays each have single pole
changeover contacts which may be used for
switching valves, actuators or contactors in high
power applications. When reactive loads are
being controlled it is essential that the output
relay contacts are protected by a suppresser to
prevent contact damage and radio frequency
interference. A 0.1µF capacitor in series with a
100 resistor, which can be purchased as a
proprietary encapsulated assembly from many
electrical suppliers, will usually provide adequate
suppression. Please note that BEKA associates'
guarantee excludes damage to the output relay
contacts.
5.4 Auxiliary outputs
In addition to the two output control relays the
BA550 has three isolated auxiliary outputs which
are referenced to a common return - terminal 6.
Each output is an open-collector NPN transistor
protected by a 1.6k series resistor and a 33V
Zener diode. For connection to other equipment
a 'pull-up' resistor will normally be required as
shown in Fig 4.
4

5.4.1 Retransmitted pulse
When enabled this output closes for 0.8ms each
time the least significant digit of the grand total is
incremented, allowing a remote instrument or
counter to record the grand total in engineering
units. The maximum output frequency is 500Hz.
The retransmitted pulse output from a BA550C
(4/20mA input) may also be used to operate a
remote counter,. Again the output represents an
integral of the input; in flow applications, the total
flow.
5.4.2 Reset status
This output closes when the batch controller is
reset, and opens when the Start button is
operated.
When the batch controller is programmed as a
totaliser the reset status output closes when the
display is reset, and opens when the first input
pulse is received.
5.4.3 Missing pulse detection (Flow alarm)
It should be noted that missing pulse detection
closes (energises) the solid state output in the
alarm condition.
BA550P (Pulse input)
The flow alarm output closes when the time
between successive input pulses exceeds a
programmed missing pulse time - see 7.3.5. A
flow alarm also de-energises both Output 1
and Output 2 relays causing the batch to
pause. In the alarm condition the Start LED is
extinguished, the STOP LED flashes and the
controller displays 'ALARM'. The alarm may
be cleared by pushing any of the front panel
buttons. This will open the flow alarm output
and briefly display 'CLEAR' until the button is
released when the last batch total will be
displayed. After the flow alarm is cleared the
batch may be resumed by operating the Start
button,. However, if input pulses are not
received within the programmed missing pulse
time the alarm will recur.
When programmed as a totaliser, the flow
alarm output 'closes' if the time between
successive input pulses exceeds the
programmed missing pulse time. In this alarm
condition the BA550 display alternates
between 'ALARM' and the selected display.
The alarm is automatically cleared when the
next input pulse arrives, but will recur if a
second pulse is not received within the
programmed missing pulse time. Therefore
when totalising continuous pulses with a period
greater than the programmed missing pulse
time, the flow alarm will be cleared for the
missing pulse time when each pulse is
received.
BA550C (4/20mA input)
The BA550C converts a 4/20mA analogue
input current into a 0 to 1kHz internal pulse
signal. The flow alarm may be set to operate
at any input current by calculating the
equivalent missing pulse time in seconds from
the formula shown below:
Missing pulse time = 1
62.5 x (Input current mA - 4)
5.5 Remote switches
For applications where large or remote
push-buttons are required, control may be
transferred to external switches with normally
open contacts - see section 7.3.2. The front
panel Start, Reset and STOP push-buttons may
be inhibited or operated in parallel with the
remote switches. Although the remote switches
are monitored with a 5V supply that will
overcome most surface contaminating films, for
industrial applications it is recommended that
high quality switches with sealed contacts are
used. See Fig 5.
Note: If the external switches are disconnected
while the front panel push-buttons are inhibited,
control can be re-established by briefly
connecting terminals 15, 16 & 17 together. This
connection automatically reprogrammes the
BA550 to respond to the front panel
push-buttons.
5.6 Power supply
Any dc supply between 20.0 and 32.5V may be
used to power the BA550, providing that the
output ripple is small enough to prevent the
instantaneous value of the supply voltage falling
below 20V. Almost all 24V industrial power
supplies comply with these requirements.
If the power supply fails the batch total, grand
total and the operating mode parameters are
stored in non-volatile memory and automatically
retrieved when the power is restored. If the
power failure occurs during a batch, restoration
of the supply will return the batch controller to a
pause condition in which both output relays are
de-energised and the Stop LED is flashing. The
BA550 will show the batch total displayed at the
time of power failure, plus any pulses that were
being processed at that time. If the retransmitted
pulse output is activated any input pulses being
processed at the time of the power failure will be
retransmitted when the supply is restored.
Pressing the Start push-button will cause the
batch to resume.
5

6. INSTALLATION
6.1 Location
The BA550 batch controller is housed in a 144 x
72mm panel mounting DIN enclosure which may
be installed into any panel providing the
environmental limits shown in the specification
are not exceeded. The BA550 has an IP65
sealed front panel. If the joint between the
controller and the panel is also to be sealed, the
panel cut-out must comply with the tighter
tolerances shown in Fig 7, and the instrument
should be secured with four panel mounting
clips.
6.2 Input conditioning
6.2.1 BA550P(pulse input)
The BA550P, which is fitted with a pulse input
card, may be conditioned by internal plug-in
links to accept one of four types of input:
Input Switching threshold
2-wire proximity detector 1.2 & 2.1mA
Voltage free contact 100 & 1,000
High voltage pulse 1 & 3V
Low voltage pulse 10 & 30mV
Access to the conditioning links is gained by
removing the rear panel of the BA550; the link
positions are shown in Fig 6.
CAUTION
Before removing the BA550 rear panel
disconnect the 24V dc supply, and
any power supply connected to the
relay contacts.
To remove the rear panel unscrew the four
corner screws and gently pull the panel
backwards taking care not to bend any of the
connector pins. There are two plug-in links,
one on the main instrument board and one on
the inside of the rear panel. By using a pair of
long nosed pliers the main board link can be
repositioned without removing the instrument
from the enclosure.
When refitting the rear panel the connector
pins must be aligned with the socket before the
panel is pushed into position.
6.2.2 BA550C(4/20mA input)
The BA550C, which is fitted with an analogue
input card, only accepts a 4/20mA current, so
no input conditioning is required.
6.3 Installation procedure
a. Insert the BA550 into the panel
aperture from the front ensuring that
the sealing gasket is correctly
positioned.
b. Clip two or four panel mounting clips
to the enclosure and evenly tighten
the screws until the instrument is
held firmly in position.
Connections to the BA550 are made via three
removable terminal blocks. Terminals 19 to 28,
which are connected to the output control relays,
are protected by an insulating cover as these
relay contacts may be used to switch high
voltages. This cover, which is secured by two
M3 screws, should be fitted after the terminals
have been wired. An additional nine way 'D'
socket is fitted to controllers incorporating the
serial communications option. When this option
is not fitted, the socket is replaced by a blanking
plate.
The terminal connections are shown in Fig 8.
7. PROGRAMMING
7.1 Security
To prevent unauthorised or accidental access to
the programme functions, three different levels
of access may be selected by linking terminals
on the rear panel.
Level Link Access
terminals
1None No programme functions
217 & 15 Only batch setpoint
317 & 16 All programme functions
The selection can be made by fitting a wire link
between the terminals, or where frequent
changes are required, the terminals may be
wired to a key operated switch to maintain
security.
7.2 Programme structure
Conditioning and calibration of the BA550 is
performed via the front panel controls. For
simplicity the adjustments are divided into three
separate programme menus as shown in Fig 9.
Programme menu Refer to
Mode parameters section 7.3 & Fig 10
Batch parameters section 7.4 & Fig 11
Rate parameters section 7.5 & Fig 12
6

Access to each of the menus is gained by
pressing Prog plus either the STOP, Batch or
Rate push-buttons simultaneously. Once within
the selected menu the required parameter can
be reached by scrolling the display using the Up
or Down push-buttons.
The three programme menus are described in
the following sections and are shown
diagrammatically in Figs 10, 11 and 12. Each
section of this manual starts with a brief
summary of all the parameters within the menu
cross referenced to full descriptions later in the
section. With a little practice this simple menu
driven system enables most adjustments to be
made without repeated reference to this manual.
7.3 Programming the mode parameters
see Fig 10
The mode parameters define the basic functions
of the BA550 and should be programmed first.
Each parameter is summarised below and cross
referenced to a full description in a following
section.
To access the mode parameter menu press the
Prog and the STOP front panel push-buttons
simultaneously. The display will show
'FUNCTION' which is the first parameter in the
menu, other parameters may be accessed by
scrolling through the menu using the Up or Down
push-buttons. After selecting the required
parameter press Ent to reveal the current value
or status.
The status of parameters can be changed by
pressing the Up push-button which will toggle the
display between the options. When the display
shows the required option press Prog to return to
the programme menu from which another
parameter may be selected for adjustment, or
the BA550 may be returned to the operating
mode by pressing the Prog push-button a second
time.
Parameters, such as the Missing Pulse Time,
which require a number to be entered are initially
displayed with one digit flashing indicating that
this digit may be adjusted by pressing the Up or
Down push-buttons. When this digit has been
set to the required number, press Ent to adjust
the next digit. When all the digits have been
adjusted press Prog to return to the programme
menu from which another parameter may be
selected for adjustment, or the BA550 may be
returned to the operating mode by pressing the
Prog push-button a second time.
Fig 10 shows a diagrammatic representation of
the mode parameter menu and the method of
moving between the parameters.
Summary of mode parameters
Parameter Description
FUNCTION Function of BA550
Conditions the BA550 as a batch
controller and rate indicator or as a
totaliser and rate indicator. When
conditioned as a totaliser, parame-
ters which only affect batch control
are omitted from the mode and
batch menus.
See section 7.3.1
CONTROL Local or remote control.
Determines whether the BA550 is
controlled by the five front panel
push-buttons, by remote switches or
by both the front panel push-buttons
and the remote switches.
See section 7.3.2
RTX O/P Retransmitted pulse
Turns the retransmitted pulse output
'ON' or 'OFF'. When 'ON' is se-
lected, the auxiliary output closes
for 0.8ms each time the least sig-
nificant digit of the grand total is in-
cremented.
See section 7.3.3
ROOT EXT Square root extraction
Turns the square root extraction for
linearising the output from differen-
tial flowmeters 'ON' or 'OFF'.
See section 7.3.4
TIMEOUT Missing pulse time
(flow alarm)
When the time between successive
input pulses exceeds the specified
missing pulse time, the flow alarm is
activated.
See section 7.3.5
INHIBIT * Missing pulse time delay
Inhibits the missing pulse detection
for a programmable time after the
start of a batch.
See section 7.3.6
S/COMMS Serial communication
Turns the serial communications
port 'ON' or 'OFF'. Note: This func-
tion is only available when the op-
tional serial communications board
is fitted.
See section 7.3.7
7

UP/DOWN *Direction of count
Determines whether the batch con-
troller counts upwards from zero, or
downwards from the batch setpoint.
See section 7.3.8
AUTO RST *Automatic reset
Automatically resets the previous
displayed batch count when the
Start button is pushed to initiate an-
other batch.
See section 7.3.9
AUTO-S * Automatic restart
Automatically resets the displayed
batch count and starts another
batch a programmable time after
completion of the previous batch.
See section 7.3.10
OVERRUN *Overrun compensation
Measures and compensates for de-
lays within the batching system.
See section 7.3.11
TEST Display test routine
Checks that the display is function-
ing correctly and shows the software
version number.
See section 7.3.12
LANGUAGEDisplay language
Selects the language in which the
menus are displayed.
See section 7.3.13
Note: Parameters marked with an * are only
included in the menu when the BA550 is
conditioned as a batch controller.
Full description of mode parameters
7.3.1 Function of BA550: FUNCTION
The BA550 may be conditioned as a batch
controller and rate indicator or as a totaliser and
rate indicator. When the totaliser function is
selected, all the functions associated with batch
control are disabled and the batch parameters
are omitted from the mode and batch menus.
To define the function of the BA550 select
'FUNCTION' from the mode programming
menu, and press Ent to reveal if the instrument is
conditioned as a batch controller 'BATCHER' or
as a totaliser 'TOTALISE'. If the function is
correct press the Prog button to return to the
menu, or press the Up button to change the
function followed by the Prog button to return to
the menu.
7.3.2 Local or remote control: CONTROL
The BA550 may be controlled by the five front
panel push-buttons, by remote switches or by
both the front panel push-buttons and remote
switches. Selection of control by remote
switches will inhibit the operation of the front
panel Start, Reset and STOP push-buttons. To
choose the method of control, select 'CONTROL'
from the mode setting menu and press Ent which
will reveal the current setting.
Display Controlled by
'LOCAL' Front panel
push-buttons
'REMOTE' Remote switches
'REM+LOC' Front panel
push-buttons and
remote switches
To change the control setting press the Up button
until the required display is obtained, followed by
the Prog push-button to return to the mode
parameter menu. The change will not be
executed until the BA550 is returned to the
operating mode.
When 'REMOTE' has been selected, local
control may be re-established in the absence of
remote switches by briefly linking terminals 15,
16 and 17 together.
7.3.3 Retransmitted output: RTX O/P
The retransmitted output closes for 0.8ms each
time the least significant digit of the grand total is
incremented. The maximum output frequency is
500Hz, above which retransmitted output errors
will begin to occur.
To activate the retransmitted output select 'RTX
O/P' from the mode parameter menu and press
Ent which will reveal if the option is 'ON' or
'OFF'. If the option is set as required press Prog
to return to the menu, or press the Up button to
change the option followed by the Prog button to
return to the menu.
7.3.4 Square root extraction: ROOT EXT
This function is primarily intended for use with
non-linear differential flowmeters which have a
square law 4/20mA output. It may also be used
with pulse inputs up to 1kHz. To prevent
cumulative errors resulting from totalising the
output of a flowmeter operating at very low flows,
below 5% of full flow (4.04mA) totalisation is
inhibited and the rate display zeroed.
8