BEKA BA324D User manual

BA324D
Intrinsically safe
loop-powered
4½ digit field
mounting indicator
issue 12
Issue: 12
4th March 2014

2
1. Description
2. Operation
2.1 Controls
3. Intrinsic Safety Certification
3.1 ATEX certificate
3.2 4/20mA input
3.3 Zones, gas groups & T rating
3.4 Certification label information
4. System Design for Hazardous Areas
4.1 Transmitter loops
4.2 Remote indication
5. Installation
5.1 Location
5.2 Installation procedure
5.3 EMC
6. Programming and Calibration
6.1 Summary of programmable functions
6.2 Root extractor
6.3 Resolution
6.4 Position of decimal point
6.5 Calibration using an external current
source.
6.6 Calibration using internal references
6.7 Conditioning sub-menu
6.7.1 AC rejection
6.7.2 Calibration of internal
references.
6.8 Function of the Ppush-button
6.9 Security code
6.10 Over and under-range
7. Calibration Examples
7.1 Using an external current source
7.2 Using the internal references
8. Maintenance
8.1 Fault finding during commissioning
8.2 Fault finding after commissioning
8.3 Servicing
8.4 Routine maintenance
8.5 Guarantee
8.6 Customer comments
9. Accessories
9.1 Units of measurement and instrument
identification.
9.2 Alarms
9.2.1 Solid state output
9.2.2 Intrinsic safety
9.2.3 Programming and adjustment
9.2.4 Alarm enable
9.2.5 Setpoint adjustment
9.2.6 Alarm function
9.2.7 Alarm output status
9.2.8 Hysteresis
9.2.9 Alarm delay
9.2.10 Alarm silence time
9.2.11 Access setpoint
9.2.12 Adjusting alarm setpoints from
display mode.
9.3 Lineariser
9.3.1 Calibration using an external
current source.
9.3.2 Calibration using internal
references.
9.4 Tare function
9.5 Display backlight
9.5.1 Separately powered backlight
9.5.2 Loop powered backlight
9.6 External switches
9.7 Pipe mounting kits
Appendix 1
FM approval for use in USA and cFM
Approval for use in Canada
Appendix 2
ATEX dust certification
Appendix 3
IECEx certification
The BA324D is CE marked to show compliance with the European Explosive Atmospheres
Directive 94/9/EC and the European EMC Directive 2004/108/EC
CONTENTS

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1. DESCRIPTION
The BA324D is a 4½ digit intrinsically safe loop
powered digital indicator which displays the current
flowing in a 4/20mA loop in engineering units. The
indicator only introduces a 1.1V drop which allows
it to be installed into almost any 4/20mA current
loop. No additional power supply or battery are
required.
The BA324D is a third generation instrument
incorporating a separate terminal enclosure.
Complying with the European Explosive
Atmospheres Directive ATEX, the instrument has
been certified intrinsically safe for use in explosive
gas and combustible dust atmospheres. ATEX
dust certification is an option - See Appendix 2.
For installation in the USA and Canada, FM and
cFM intrinsic safety and nonincendive certification
are also available. See Appendix 1.
All versions have IECEx certification.
The main application of the BA324D is to display a
measured variable or control signal in a hazardous
process area. The zero and span of the display
are independently adjustable so that the indicator
can be calibrated to display any variable
represented by the 4/20mA current, e.g.
temperature, flow, pressure or level.
The BA324D has been certified intrinsically safe by
ITS to the European ATEX Directive 94/9/EC. The
EC-Type Examination Certificate specifies that
under fault conditions the voltage, current and
power at input terminals 1 and 3 will not exceed
those specified for simple apparatus in Clause 5.4
of EN50020:1994.
The indicator is housed in a robust IP66 glass
reinforced polyester (GRP) enclosure with an
armoured glass window.
2. OPERATION
Fig 1 shows a simplified block diagram of a
BA324D. The 4/20mA input current flows through
resistor R1 and forward biased diode D1. The
voltage developed across D1, which is relatively
constant, is multiplied by a switch mode power
supply and used to power the instrument. The
voltage developed across R1, which is proportional
to the 4/20mA input current, provides the input
signal for the analogue to digital converter.
Each time a 4/20mA current is applied to the
instrument, initialisation is performed. After a short
delay the following display sequence occurs:
-1.8.8.8.8 Display test in which all
segments of the display
are activated for 0.5
seconds.
Blank display For 0.5 seconds.
Decimal points For 3 seconds.
cycled
Input current Using calibration
display in information stored in
engineering instrument memory.
units.
Fig 1 Simplified block diagram of BA324D
2.1 Controls
The BA324D is controlled and calibrated via four
push-button switches which are located behind the
instrument control cover, or as an option on the
instrument cover. In the display mode i.e. when
displaying a variable, these switches have the
following functions:
PWhile this button is pushed the
indicator will display the input current in
mA, or as a percentage of the
instrument span depending upon how
the indicator has been programmed.
When the button is released the normal
display in engineering units will return.
The function of this push-button is
modified when alarms or a tare function
are fitted to the indicator.

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Down While this button is pushed the
indicator will display the number which
the indicator has been calibrated to
display with a 4mA input. When
released the normal display in
engineering units will return.
Up While this button is pushed the
indicator will display the number which
the indicator has been calibrated to
display with a 20mA input. When
released the normal display in
engineering units will return.
ENo function in the display mode.
3. INTRINSIC SAFETY CERTIFICATION
3.1 ATEX certificate
The BA324D has been issued with an EC-Type
Examination Certificate number ITS99ATEX2002
by Intertek Testing and Certification Ltd showing
compliance with the European ATEX Directive
94/9/EC for Group II, Category 1, gas and dust
atmospheres, EEx ia IIC. The instrument bears
the Community Mark and, subject to local codes of
practice, may be installed in any of the European
Economic Area (EEA) member countries. ATEX
certificates are also acceptable for installations in
Switzerland.
This manual describes installations in explosive
gas atmospheres which conform with BS
EN60079:Part 14:2003 When designing systems
for installation outside the UK, the local Code of
Practice should be consulted.
For use in the presence of combustible dust,
please refer to Appendix 2 which describes
installations complying with EN 61241-14.
3.2 4/20mA input
In Europe, sources of energy which do not
generate more than 1.5V; 100mA and 25mW are,
for intrinsic safety purposes, considered to be
simple apparatus (Clause 5.4 of EN50 020:1994).
Although the BA324D indicator does not itself
comply with the requirements for simple apparatus,
the EC-Type Examination Certificate specifies that
under fault conditions the voltage, current and
power at the 4/20mA input terminals 1 and 3 will
not exceed those specified for simple apparatus in
Clause 5.4 of EN50020:1994. This
allows the BA324D to be connected into any
intrinsically safe circuit protected by a Zener barrier
or galvanic isolator, providing the output
parameters of the circuit do not exceed:
Uo = 30V dc
Io = 200mA
Po = 0.85W
For this reason the BA324D only has an apparatus
certificate. No system certificate has been issued,
or is required, because the system certificate of the
loop into which the indicator is connected remains
valid. Note: The optional display backlight does
have a system certificate.
The BA324D EC-Type Examination Certificate
specifies that the maximum equivalent capacitance
and inductance between the two 4/20mA input
terminals is: Ci = 20nF
Li = 10µH
To determine the maximum permissible cable
parameters these figures must be subtracted from
the maximum cable capacitance and inductance
permitted by the system certificate of the loop into
which the BA324D is connected.
3.3 Use in explosive gas atmospheres
Zones, gas groups and T rating
The BA324D has been certified EEx ia IIC T5.
When connected to a suitable system the indicator
may be installed in:
Zone 0 explosive gas air mixture
continuously present.
Zone 1 explosive gas air mixture likely
to occur in normal operation.
Zone 2 explosive gas air mixture not
likely to occur, and if it does will
only exist for a short time.
Be used with gases in groups:
Group A propane
Group B ethylene
Group C hydrogen
Having a temperature classification of:
T1 450°C
T2 300°C
T3 200°C
T4 135°C
T5 100°C

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This allows the BA324D to be installed in all Zones
and to be used with most common industrial
gases.
3.4 Certification Label Information
The certification label is fitted in a recess on the
top outer surface of the enclosure. It shows the
ATEX certification information plus BEKA
associates name and location. Non European
certification information may also be included. The
instrument serial number and date of manufacture
are recorded on a separate label inside the
terminal compartment.
4. SYSTEM DESIGN FOR HAZARDOUS
AREAS
4.1 Transmitter loops
A BA324D indicator may be connected in series
with almost any intrinsically safe 4/20mA current
loop and calibrated to display the measured
variable or control signal in engineering units.
There are two basic design requirements:
1. The intrinsic safety output parameters of the
4/20mA loop, which are defined by the Zener
barrier or galvanic isolator, must be less
than: Uo = 30V dc
Io = 200mA
Po = 0.85W
2. The loop must be able to tolerate the
additional 1.1V required to operate the
indicator.
Fig 2 illustrates a typical application in which a
BA324D indicator is connected in series with a 2-
wire transmitter protected by a Zener barrier.
Fig 2 BA324D in a transmitter loop
4.2 Remote indication
A BA324D may be driven from a 4/20mA safe area
signal via an intrinsically safe interface to provide a
remote indication within a hazardous area. The
type of interface is not critical, either a Zener
barrier or a galvanic isolator may be used,
providing the output parameters of the interface
are : Uo less than 30V dc
Io less than 200mA
Po less than 0.85W
Note: when the hazard is a IIC gas, and two single
channel Zener barriers or a two channel Zener
barrier are used, only one barrier or channel may
be a 28V 300ohm device.
Again it is necessary to ensure that the voltage
capability of the 4/20mA signal is sufficient to drive
the indicator plus the voltage drop introduced by
the intrinsically safe interface. Figs 3A, 3B and 3C
show the alternative circuits which may be used.
If one side of the 4/20mA current loop may be
earthed, a single channel Zener barrier provides
the lowest cost protection. If the 4/20mA signal is
not isolated, then two Zener barriers, a two
channel Zener barrier or a galvanic isolator must
be used.

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Fig 3A Simplest circuit with one side of 4/20mA
current loop connected to earth
Fig 3B Two Zener barrier channels are
required if the 4/20mA current
loop can not be earthed at the
barrier busbar.
Fig 3C Galvanic isolator can be used with any
4/20mA current loop.
5. INSTALLATION
5.1 Location
The BA324D indicator is housed in a robust IP66
glass reinforced polyester (GRP) enclosure
incorporating an armoured glass window and
stainless steel fittings making it suitable for exterior
mounting in most industrial installations, including
off-shore and waste water treatment. Please
consult BEKA associates if high vibration is
anticipated.
The BA324D is surface mounting, but may be pipe
or stem mounted using the accessory kits
described in sections 9.7 and 9.8 of this manual.
The field terminals and the two mounting holes are
located in a separate compartment with a sealed
cover allowing the instrument to be installed
without exposing the display assembly.
Terminals 2 and 4 are internally joined and may be
used for linking the return 4/20mA wire - see Fig 2.
Similarly terminals 5 and 6 are internally joined and
may be used for linking cable screens. The
BA324D earth terminal is connected to the internal
EMC filters. For maximum radio frequency
interference rejection this terminal should be
connected to a local earth, or to a cable screen
which is earthed in the safe area. To prevent
circulating currents, cable screens should only be
earthed in the safe area.
The BA324D enclosure is fitted with a bonding
plate to ensure electrical continuity between the
three conduit / cable entries.
5.2 Installation Procedure
Fig 4 illustrates the instrument installation
procedure.
a. Remove the instrument terminal cover by
unscrewing the two captive 'A' screws.
b. Mount the instrument on a flat surface and
secure with screws or bolts through the two
'B' holes. Alternatively use one of the pipe or
stem mounting kits described in sections 9.7
and 9.8
c. Remove the temporary hole plug and install a
cable gland or conduit fitting with required
ingress protection. If more than one entry is
required, replace one or both IP66 stopping
plugs with a cable gland or conduit fitting
having the required ingress protection.
d. Connect the field wiring to the terminals as
shown in Fig 5.
e. Replace the instrument terminal cover and
evenly tighten the two 'A' screws.

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Fig 4 BA324D installation procedure
5.3 EMC
The BA324D complies with the requirements of the
European EMC Directive 2004/108/EC. For
specified immunity all wiring should be in screened
twisted pairs, with the screens earthed in the safe
area
Additional immunity may be obtained by
connecting the BA324D earth terminal to a local
earth, or to a cable screen which is earthed in the
safe area. If this terminal is not connected,
personal and intrinsic safety will not be degraded.
Fig 5 Dimensions and terminal connections

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6. PROGRAMMING & CALIBRATION
The BA324D is programmed and calibrated via
four push-buttons which are located behind the
instrument control cover. When frequent access
to the push-buttons is required, the indicator can
be supplied with external membrane push-buttons
mounted on the outside of the control cover.
All the programming functions are contained in an
easy to use menu which is shown diagramatically
in Fig 6. Each function is summarised in section
6.1 which includes references to more detailed
information. Although this simple menu driven
system enables most adjustments to be made
without repeated reference to this manual, we
recommend that at least the summary of the
programmable functions in section 6.1 is read
before attempting programming or recalibration.
When the indicator is fitted with alarms,
linearisation or a tare function, the basic menu is
expanded to include functions associated with
these optional features. All the optional functions
are described in section 9 of this manual.
Throughout this manual push-buttons are shown in
italics e.g. P or Up push-button, and legends
displayed by the indicator are shown within
inverted commas e.g. 'CAL' and ' ALr2'.
Access to the programme menu is obtained by
operating the Pand Epush-buttons
simultaneously. If the instrument is not protected
by a security code the first parameter 'root' will be
displayed. If a security code other than the default
code 0000 has already been entered, the indicator
will display 'COdE'. Press Pto clear this prompt
and enter the security code for the instrument
using the Up, Down and Ppush-buttons. If the
correct code has been entered pressing Ewill
cause the first parameter 'root' to be displayed. If
an incorrect code is entered the indicator will
return to the display mode.
Once within the menu the required parameter can
be reached by scrolling through the main menu
using the Up and Down push-buttons as shown in
Fig 6. When returning to the display mode
following recalibration or changes to any
parameters, the indicator will display circulating
decimal points for a few seconds while the new
information is stored in permanent memory.
All new BA324D indicators are supplied calibrated
as requested at the time of ordering. If calibration
is not requested, the indicator will be set to display
0.00 with 4mA input, and 100.00 with 20mA input,
but can easily be re-calibrated on-site.
6.1 Summary of programmable functions
This section summarises all of the programmable
functions and when read in conjunction with Fig 6
provides sufficient information to condition and
calibrate the indicator. A cross-reference to more
information is given for each function.
Display Description of function
'root' Square root extractor
Turns the square root extractor for
linearising the output from differential
flowmeters 'On' or 'OFF'. This function
is omitted when a lineariser is installed.
See section 6.2
'rESn' Display resolution
Selects the resolution of the least
significant display digit. May be set to
1, 2, 5 or 10 digits.
See section 6.3
'd.P.' Decimal point
Positions the dummy decimal point
between any of the digits or turns it off.
See section 6.4
'CAL' Calibration of display using external
current source.
Enables the zero and span of the
indicator to be adjusted using an
external current source such as a
calibrator. Also enables a complete
loop to be calibrated from primary
element to the indicator display.
When used with an accurate traceable
current source this is the preferred
method of calibration.
See section 6.5

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Display Description of function
'SEt' Calibration of display using internal
references.
Enables the zero and span of the
indicator to be adjusted without the
need for an accurate input current or
disconnection from the 4/20mA loop.
See section 6.6
'Cond' Indicator conditioning
This function provides access to a sub-
menu enabling the mains (line)
frequency rejection to be selected and
the internal references to be calibrated.
Because these parameters will alter the
indicator display, they are contained in
a sub-menu to prevent inadvertent
adjustment.
Caution
If the mains filter frequency is
changed, the indicator display
and internal references (if used)
must be recalibrated.
See section 6.7
'FrE' Frequency rejection
Defines the mains (line) frequency at
which the indicator has maximum ac
rejection. 50 or 60Hz may be selected.
This function must be set before the
instrument is calibrated as it affects the
indicator display.
See section 6.7.1
'rEF' Calibration of internal references
The indicator contains two references
representing a 4 and 20mA. input
These enable the BA324D display to
be calibrated without the need for an
external calibrator, or disconnection
from the 4/20mA loop. See the SEt
function.
If the SEt or C--P functions are to be
used, the internal references should be
periodically calibrated.
See section 6.7.2
Display Description of function
'C - - P' Function of P push-button
The BA324D may be programmed to
display the input current in milliamps or
the input current as a percentage when
the Ppush-button is operated.
See section 6.8
'COdE' Security code
Defines a four digit numeric code which
must be entered to gain access to
programmable functions. Default code
0000 disables the security function and
allows unrestricted access to all
programmable functions. See section
6.9

10

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6.2 Root extractor: root
This function is primarily intended for use with
differential flowmeters which have a square law
4/20mA output. To activate the square root
extractor select 'root' from the menu and press P
which will reveal if the function is 'On' or 'OFF'. If
the function is set as required, press Eto return to
the menu, or press the Up or Down button to
change the setting, followed by the E button to
return to the main menu. For reference, the
following table shows the output current from a
non-linearised differential flowmeter. Below 5% of
flow the BA324D display is forced to zero.
% of full flow Current output mA
5.0 4.04
10.0 4.16
25.0 5.00
50.0 8.00
75.0 13.00
100.0 20.00
6.3 Resolution: rESn
This function defines the resolution of the least
significant display digit. Decreasing the display
resolution can improve the readability of a noisy
signal. Select 'rESn' from the menu and press P
which will reveal the current display resolution. To
change the resolution press the Up or Down button
to select 1, 2, 5 or 10 digits, followed by the E
button to return to the menu.
6.4 Position of the decimal point: d.P.
A dummy decimal point can be positioned between
any of the digits or may be absent. To position
the decimal point select 'd.P.' from the menu and
press P . The decimal point can then be moved or
turned off by pressing the Up or Down push-
button, followed by Eto return to the menu.
6.5 Calibration of display using an external
current source: CAL
This function enables the zero and span of the
indicator to be adjusted using an external
calibrated current source. When used with an
accurate traceable current source this is the
preferred method of calibration.
To calibrate the indicator select 'CAL' from the
main menu and press P. The indicator will display
'ZErO' which is a request for a 4mA input current.
Adjust the external current calibrator to 4.000mA
and again press P which will reveal the current
zero display. Each digit of the indicator display
can be changed by pressing the Up or Down
buttons. When the first digit is correct pressing P
will transfer control to the next digit.
When all the digits have been adjusted, press E to
enter the new zero. The indicator will display 'Ent'
for a few seconds while the information is being
stored in memory, and will then return to the 'ZErO'
prompt .
To adjust the display at 20mA, press the Up button
which will cause the indicator to display 'SPAn'.
Adjust the external current calibrator to 20.000mA
and again press P which will reveal the existing
full scale display. Each digit of the indicator
display can be changed by pressing the Up or
Down buttons. When the first digit is correct,
pressing Pwill transfer control to the next digit.
When all the digits have been adjusted press E to
enter the new span. The indicator will display 'Ent'
for a few seconds while the information is being
stored in memory, and will then return to the
'SPAn' prompt. Finally press Eagain to return to
the main menu.
This function may also be used when calibrating a
complete loop from primary element to indicator
display e.g. when the indicator is displaying the
output from a resistance thermometer transmitter.
6.6 Calibration of display using internal
references: SEt
This function enables the zero and span of the
indicator to be adjusted without the need for an
accurate external current source, or for
disconnection from the 4/20mA loop. The
accuracy of this method depends upon the
accuracy of the internal references which should
be regularly calibrated as described in section
6.7.2
To calibrate the indicator select 'SEt' from the main
menu and press P. The indicator will display
'ZErO', pressing Pagain will reveal the current
display at 4mA. Each digit of the indicator display
can be changed by pressing the Up or Down
buttons. When the first digit is correct, pressing P
will transfer control to the next digit. When the
least significant digit has been adjusted, press Eto
return to the 'ZErO' prompt which completes the
adjustment.
To adjust the display at 20mA, press the Up button
which will cause the indicator to display 'SPAn'.
Pressing P again will reveal the indicator display.
Each digit can be changed by pressing the Up or
Down buttons. When the first digit is correct,
pressing Pwill transfer control to the next digit.
When the least significant digit has been adjusted
press E to return to the 'SPAn' prompt followed by
Eto return to the menu.

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6.7 Conditioning sub-menu: Cond
This sub-menu allows the mains (line) frequency at
which the indicator has maximum ac rejection to
be selected and the two internal references to be
calibrated. These functions are contained in a
sub-menu to minimise the possibility of inadvertent
adjustment. To gain access to the sub-menu
select 'Cond' from the main menu and press P.
The indicator will display 'SurE' to warn that
changing the parameters in the sub-menu will
change the indicator display. Pressing P again will
give access to the sub-menu, or pressing E will
return the indicator to the main menu.
6.7.1 AC rejection: FrE
Caution
If the mains filter frequency is
changed, the indicator display and
internal references (if used) must be
recalibrated.
To provide maximum low frequency rejection the
internal digital filter may be set to operate at 50 or
60Hz to correspond with the local mains (line)
frequency. To change the frequency select 'FrE'
from the 'Cond' sub-menu and press Pwhich will
reveal the current setting. The setting can be
changed by pressing the Up or Down buttons
followed by the Ebutton to return to the sub-menu.
6.7.2 Calibration of internal references: rEF
The indicator contains two references representing
4 and 20mA. These references are used in the
'SEt' function which enables the indicator display to
be calibrated without an external current calibrator.
They are also used in the 'C--P' function when the
P push-button is programmed to display the input
current in the display mode. If neither of these
functions is to be used, it is not necessary to
calibrate the internal references.
To calibrate the references select 'rEF' from the
sub-menu and press Pwhich will result in a
'0.004A' prompt being displayed. Adjust the
external current calibrator to 4.000mA and again
press P . The indicator will display 'Ent' when the
4mA reference has been updated and will then
return to the '.004A' prompt.
To re-calibrate the 20mA internal reference, press
the Up button which will cause the indicator to
display '.020A'. Adjust the external current
calibrator to 20.000mA and again press P . The
indicator will display 'Ent' when the 20mA
reference has been updated and will then return
to the '.020A' prompt. Two operations of the E
button will return the indicator to the main menu.
The accuracy of the internal references, and hence
the display accuracy, will depend upon the
accuracy of the external current source. With a
maximum span of 19999 the indicators have a
display resolution of 0.8µA, we therefore
recommend that the accuracy of the external
current source used for calibration is greater than
0.4µA.
6.8 Function of the Ppush-button: C - - P
This parameter defines the function of the Ppush-
button when the indicator is in the display mode.
While the button is operated the indicator will
display the input current in milliamps, or as a
percentage of the span.
To check or change the parameter select 'C - -P'
from the main menu and press Pto reveal the
current setting. Pressing the Up or Down button
will toggle the setting between '4-20' the current
display and 'PC' the percentage display. When set
as required press Eto return to the main menu.
Accuracy of the current display depends upon the
accuracy of the internal references which should
be periodically calibrated - see section 6.7.2
6.9 Security code: COdE
The calibration and conditioning of the instrument
may be protected by a four digit security code
which must be entered before access to the
programme menu is granted. New instruments
are programmed with the default security code
0000 which allows unrestricted access to all
programming functions.
To enter a new security code select 'COdE' from
the menu and press P which will cause the
indicator to display the current security code. Each
digit of the code can be changed using the Up and
Down push-buttons, and the Pbutton to move to
the next digit. When the required code has been
entered press E to return to the main menu. The
revised security code will be activated when the
indicator is returned to the operating mode.
If the security code is lost, access to the
programmable functions can be obtained by
moving the internal security link to the override
position. The security code can then be viewed
by selecting 'CodE' from the main menu and
pressing P.

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To gain access to the security code link, remove
the instrument control cover, and if fitted unplug
the external switch connector. The security code
override link is located on the inner row of five pins
as shown in Fig 7.
Fig 7 Location of security code override link
6.10 Over and under-range
If the indicator display range is exceeded, the four
least significant digits will be blanked. Under-
range is indicated by '-1' and over-range by '1'.
Under and over-range are also indicated if the
input current falls below approximately 3.5mA or
rises above approximately 21mA.
If the input current falls below 3mA the instrument
initialisation sequence is performed as described
in section 2.
7. CALIBRATION EXAMPLES
The following examples illustrate the two ways in
which a BA324D indicator may be calibrated.
7.1 Using an external current source
The BA324D indicator is required to display:
-50.0 with a 4mA input
1050.0 with a 20mA input
from a linear transducer. Maximum display
resolution is required, the frequency of the mains
supply is 50Hz and the existing security code is
1209. In the operating mode the indicator is
required to display the input current as a
percentage of span when the Ppush-button is
operated.
Step 1 Connect indicator to calibrator
Connect the indicator to an accurate
external current source. Terminal 1
positive. The indicator will
automatically perform the initialisation
routine described in section 2, and then
display the input current using the
existing calibration information.
Step 2 Enter programming mode
With an input current between 4 and
20mA put the indicator in the
programming mode by simultaneously
pressing P and E. The indicator will
respond by displaying 'COdE'. Press P
to clear this prompt and set the display
to the security code 1209 using the Up,
Down and Ppush-buttons. Pressing E
will enter the code, and after a few
seconds during which the decimal
points will be scrolled, the first
parameter 'root' in the main menu will
be displayed.
Step 3 Square root extraction
With 'root' displayed, press Pwhich
will reveal the root extractor status.
The root extractor can be turned on or
off by the Up or Down buttons. Select
'OFF', and press Eto return to the main
menu.
Step 4 Select frequency of maximum
mains (line) rejection
Scroll though the main menu until
'Cond' is displayed. Enter the sub-
menu by pressing Ptwice and select
the 'FrE' function. Using the Up or
Down buttons select '50', and then
press Etwice to return to the main
menu.

14
Step 5 Define function of P push-button
Select 'C--P' from the main menu and
press P to reveal the function of the P
button in the display mode. Select
percentage 'PC' and return to the main
menu by pressing E
Note: Because an input current display
in milliamps is not required, it is not
necessary to calibrate the two internal
references.
Step 6 Position dummy decimal point
Scroll though the main menu until 'd.P.'
is displayed and then press P. Using
the Up and Down push-buttons position
the dummy decimal point in front of the
least significant digit.
Press Eto return to the main menu.
Step 7 Calibrate the display
Scroll through the main menu until
'CAL' is displayed. Press P and the
indicator will request a 4mA input by
displaying 'ZErO'. Set the input current
to 4.0000 ± 0.0004mA and press P
again which will reveal the existing zero
display. Using the Up, Down and P
push-buttons enter the required zero
display of -50.0 Press Eto return to
the 'ZErO' prompt.
Press the Up push-button and the
indicator will request a 20mA input by
displaying 'SPAn'. Set the input
current to 20.0000 ± 0.0004mA and
again press Pwhich will reveal the
existing display at 20mA. Using the
Up, Down and Ppush-buttons enter the
required display of 1050.0
Press Etwice to return to the main
menu.
Step 8 Return to the display mode
Following completion of calibration
return to the display mode by pressing
'E'.
7.2 Using the internal references
As in 7.1 the BA324D is required to display:
-50.0 with a 4mA input
1050.0 with a 20mA input
from a linear transducer. Maximum display
resolution is required, the frequency of the mains
supply is 50Hz and the existing security code is
1209. In the operating mode the indicator is
required to display the input current in milliamps
when the Ppush-button is operated.
This example assumes that the internal references
have been routinely calibrated.
Step1 Enter the programming mode
With an input current between 4 and
20mA put the indicator in the
programming mode by simultaneously
pressing P and E. The indicator will
respond by displaying 'COdE'. Press P
to clear this prompt and set the display
to the security code 1209 using the Up,
Down and Ppush-buttons. Pressing E
will enter the code, and after a few
seconds during which the decimal
points will be scrolled, the first
parameter 'root' in the main menu will
be displayed.
Step 2 Square root extractor
With 'root' displayed, press Pwhich
will reveal the root extractor status.
The root extractor can be turned on or
off by the Up or Down buttons. Select
'OFF', and press Eto return to the main
menu.
Step 3 Select frequency of max mains (line)
rejection
Scroll though the main menu until
'Cond' is displayed. Enter the sub-
menu by pressing Ptwice and select
the 'FrE' function. Using the Up or
Down buttons select '50', and then
press Etwice to return to the main
menu.
Step 4 Define function of P push-button
Select 'C--P' from the main menu and
press Pto reveal the function of the P
button in the display mode. Select '4-
20' and return to the main menu by
pressing E.
Step 5 Position dummy decimal point
Select 'd.P' from the main menu and
then press P. Using the Up and Down
push-buttons position the dummy
decimal point in front of the least
significant digit.
Press Eto return to the main menu.
Step 6 Calibrate display
With any input current between 4 and
20mA select 'SEt' from the main menu
and press P. The indicator will display
'ZErO' in the sub-menu; press Pto
reveal the existing zero display.

15
Using the Up, Down and P push-
buttons enter the required zero display
of -50.0 Press Eto return to the
'ZErO' prompt.
Again with any input current between 4
and 20mA press the Up push-button
and the indicator will display 'SPAn'.
Press P to reveal the existing span
display. Using the Up, Down and P
push-buttons enter the required span
display of 1050.0 Press Eto return to
the 'SPAn' prompt. Press Eagain to
return to the main menu.
Step 7 Return to display mode
Following completion of calibration
return to the display mode by pressing
'E'.
8. MAINTENANCE
8.1 Fault finding during commissioning
If a BA324D fails to function during commissioning
the following procedure should be followed:
Symptom Cause Solution
No display Incorrect There should be 1V
wiring between terminals 1 &
3 with terminal 1
positive.
No display Incorrect Check that a current
and no volts wiring or is flowing in the loop.
between no power
terminals supply.
1 and 3. Insufficient Check supply voltage
loop voltage and voltage drops
to operate caused by all
indicator components in the loop.
Indicator Positive The indicator has been
displays 1 over-range incorrectly calibrated &
is trying to display a
number greater than
19999.
Indicator Negative The indicator has been
displays -1 over-range incorrectly calibrated &
is trying to display a
number less than
-19999.
Unstable 4/20mA input Check loop supply
display has a large voltage.
ripple content.
Unable to Incorrect Enter correct security
enter the security code or fit security
programme code link in override position.
mode entered. See Fig 7.
8.2 Fault finding after commissioning
ENSURE PLANT SAFETY BEFORE
STARTING MAINTENANCE
Live maintenance is permitted on
intrinsically safe equipment installed in a
hazardous area, but only certified test
equipment should be used unless a gas
clearance certificate is available.
If a BA324D fails after it has been functioning
correctly, the following table may help to identify
the cause of the failure.
Symptom Cause Solution
No display No power Check that a current
and no volts supply is flowing in the loop.
between
terminals
1 and 3.
Unstable 4/20mA input Check loop supply
display has a large voltage.
ripple.
Incorrect Digital filter Recalibrate
calibration FrE has been
changed after
indicator was
calibrated.
If this procedure does not reveal the cause of the
fault, it is recommended that the instrument is
replaced. This can be done without disconnecting
power, but while the indicator is disconnected the
4/20mA loop will be open circuit. Alternatively the
electronic assembly may be exchanged as
described in section 8.3
8.3 Servicing
We recommend that faulty instruments
and instrument assemblies are returned
to BEKA associates or to our local agent
for repair.
Electronic components must not be
replaced or repaired on site.
To simplify servicing all BA324D indicators use a
common display assembly. Depending upon the
accessories fitted, one spare display assembly
may be used to repair any BA324D which fails.
The exchange may be made without disconnecting
power, the 4/20mA loop will continue to function
but the indicator voltage drop will increase from 1V
to 4V without the display assembly.

16
To exchange the display assembly remove the
terminal cover by unscrewing the two 'A' screws
which will reveal two concealed 'D' screws. If the
instrument is fitted with external push-buttons also
unscrew the two 'C' screws securing the buttons
and un-plug the five way connector. Finally
unscrew all four 'D' screws and carefully lift off the
front of the instrument. The location of all the
screws is shown in Fig 4. The display assembly is
secured by three Pozi headed screws which
should be removed. If the instrument is fitted with
a backlight or alarms the fly-leads connecting the
accessory boards to the terminals should be un-
plugged. The replacement display assembly may
then be installed and the enclosure reassembled.
If after replacement of the display assembly the
instrument still does not function, it is likely that the
fault is within the protection components on the
terminal assembly. Terminal assemblies may be
exchanged on site providing the replacement
includes terminals for any accessories fitted to the
display assembly i.e. terminals for backlight and /
or alarms.
8.4 Routine maintenance
The mechanical condition of the instrument and
electrical calibration should be regularly checked.
The interval between inspections depends upon
environmental conditions. We recommend that
initially instrument calibration should be checked
annually.
8.5 Guarantee
Indicators which fail within the guarantee period
should be returned to BEKA associates or our local
agent. It is helpful if a brief description of the fault
symptoms is provided.
8.6 Customer comments
BEKA associates is always pleased to receive
comments from customers about our products and
services. All communications are acknowledged
and whenever possible, suggestions are
implemented.
9. ACCESSORIES
9.1 Units of measurement and instrument
identification
All BA324D indicators are fitted with a blank label
around the liquid crystal display. This label can be
supplied printed with any units of measurement
and tag information specified at the time of
ordering. Alternatively the information may be
added on-site via an embossed strip, dry transfer
or a permanent marker.
To gain access to the display label remove the
terminal cover by unscrewing the two 'A' screws
which will reveal two concealed 'D' screws. If the
instrument is fitted with external push-buttons, also
unscrew the two 'C' screws securing the buttons
and un-plug the five way connector. Finally
unscrew all four 'D' screws and carefully lift off the
front of the instrument. The location of all the
screws is shown in Fig 4.
Add the required legend to the display label, or
replace with a new pre-printed self-adhesive label
which is available from BEKA associates
The BA324D can also be supplied with a blank or
custom engraved stainless steel plate secured by
two screws to the side of the instrument enclosure.
This plate can accommodate:
1 row of 9 alphanumeric characters 10mm high
or 1 row of 11 alphanumeric characters 7mm high
or 2 rows of 18 alphanumeric characters 5mm high.
9.2 Alarms
The BA324D can be supplied with two solid state
single pole alarm outputs which may be
independently programmed as high or low alarms
with normally open or normally closed outputs. Fig
8 illustrates the conditions available and shows
which are fail safe, i.e. output is in the alarm
condition (open) when the 4/20mA input current is
zero.
WARNING
These alarm outputs should not be used
for critical safety applications such as a
shut down system.
When an alarm is activated the BA324D display
alternates between the measured value and an
alarm identification.

17
Fig 8 Alarm outputs
Programmable functions for each alarm include
adjustable setpoint, hysteresis, alarm delay and
alarm accept.
9.2.1 Solid state output
Each alarm has a galvanically isolated single pole
solid state switch output as shown in Fig 9. The
outputs are polarised and current will only flow in
one direction. Terminals 8 and 10 should be
connected to the positive side of the supply.
Ron = 5ohms + 0.6V
Roff = greater than 180k
Note: Because of the series protection diode
some test meters may not detect a closed alarm
output.
Fig 9 Equivalent circuit of each alarm output
9.2.2 Intrinsic safety
Each alarm output is a separate galvanically
isolated solid state switch. The EC-Type
Examination Certificate specifies that under fault
conditions the voltage, current and power at each
alarm output will not exceed those specified for
simple apparatus in Clause 5.4 of EN50020:1994.
This allows each of the BA324D alarm outputs to
be connected to any intrinsically safe circuit
protected by a Zener barrier or galvanic isolator
providing that the output parameters of each
circuit do not exceed:
Uo 28V dc
Io 200mA
Po 0.85W
No system certificate has been issued for the
BA324D alarm outputs, as the system certificate
for the circuit to which the alarms are connected
remains valid. Hazardous or safe area loads may
be switch as shown in Fig 10.
The maximum equivalent capacitance and
inductance of each BA324D alarm output is:
Ci = 40nF
Li = 20µH
To determine the maximum permissible cable
parameters, the equivalent alarm output
parameters must be subtracted from the maximum
cable capacitance and inductance specified by the
system certificate of the circuit connected to each
alarm.
Fig 10 Typical alarm application

18
9.2.3 Programming and adjustment
When an alarm card is added to a BA324D the
main programme menu is extended as shown in
Fig 11. The additional functions appear between
'Cond' and 'C--P' in the main menu. For simplicity
Fig 11 only shows the additional functions
available on alarm 1, but alarm 2 has identical
facilities.
The following table summarises each of the alarm
programme functions and includes a cross
reference to more detailed information. Again
only the functions on alarm 1 are listed, but alarm
2 has identical facilities.
Summary of programmable alarm functions
Display Description of function
'EnbL' Alarm enable
Enables or disables the alarm function
without changing the alarm parameters.
See section 9.2.4
'SP1' Alarm setpoint 1
Adjusts the alarm setpoint. The alarm
is activated when the indicator display
equals the setpoint.
See section 9.2.5
'HI.LO' Alarm function
Defines whether the alarm has a high
or low function.
See section 9.2.6
'no.nc' Normally open or normally closed
output
Determines whether the single pole
alarm output is open or closed in the
alarm condition.
See section 9.2.7
'HStr' Hysteresis
Adjusts the alarm hysteresis.
See section 9.2.8
'dELA' Alarm delay time
Adjusts the delay between the display
equalling the setpoint and the alarm
output being activated.
See section 9.2.9
Display Description of function
'SIL' Alarm silence time
Defines the time that the alarm output
remains in the non-alarm condition
following acceptance of an alarm.
See section 9.2.10
'AcSP' Access setpoint
Sub-menu which enables direct access
to the alarm setpoints from the indicator
display mode, and defines a separate
security code.
See section 9.2.11
9.2.4 Alarm enable: EnbL
This function allows the alarm to be enabled or
disabled without altering any of the alarm
parameters. To check or change the function
select 'EnbL' from the alarm menu and press P
which will reveal the current setting. The function
can be changed by pressing the Up or Down
button followed by the Ebutton to return to the
alarm menu.
9.2.5 Setpoint adjustment: SP1 and SP2
The setpoint of each alarm may be positioned
anywhere between -19999 and 19999 providing
this corresponds to an input current between 3.8
and 20.2mA. e.g. If the indicator has been
calibrated to display 0 with 4mA input and 10000
with 20mA input, the two alarm setpoints may be
positioned anywhere between -125 and 10125.
To adjust the setpoint select 'SP1' or 'SP2' from
the alarm menu and press Pwhich will reveal the
existing alarm setpoint. Each digit of the setpoint
can be adjusted using the Up and Down push-
buttons, and the Pbutton to move to the next digit.
When the required setpoint has been entered
press E to return to the alarm menu.
9.2.6 Alarm function: HI.LO
Each alarm can be conditioned as a high or low
alarm. To check or change the alarm function
select 'HI.LO' from the alarm menu and press Pto
reveal the current setting. The function can be
changed by pressing the Up or Down buttons
followed by the Ebutton to return to the alarm
menu.
9.2.7 Alarm output status: no.nc
This function allows the alarm output to be open or
closed in the alarm condition. When deciding
which is required, care must be taken to ensure
that the alarm output is fail safe. See Fig 8.

19
CAUTION
When the 4/20mA supply is removed
both alarm outputs will open
irrespective of conditioning.
Therefore for fail safe operation both
alarm outputs should be
programmed to be open in the alarm
condition.
To check or change the alarm output status select
'no.nc' from the alarm menu and press Preveal the
current setting. The function can be changed by
pressing the Up or Down button followed by the E
button to return to the alarm menu.
9.2.8 Hysteresis: HStr
During programming hysteresis is shown in the
units the indicator has been calibrated to display.
To adjust the hysteresis, select 'HStr' from the
alarm menu and press Pwhich will reveal the
existing figure. Each digit can be adjusted using
the Up and Down push-buttons, and the Pbutton
to move to the next digit. When the required
hysteresis has been entered, press E to return to
the alarm menu.
e.g. An indicator calibrated to display 0 to 10000,
with a high alarm set at 9000 and hysteresis of 200
will perform as follows:
High alarm will be activated when display
equals or exceeds 9000, but will not reset
until the display falls below 8800.
9.2.9 Alarm delay: dELA
This function enables activation of the alarm output
to be delayed for a fixed time following the alarm
condition occurring. The delay can be
programmed in 1 second increments up to 3600
seconds. If a delay is not required zero should be
entered. To adjust the delay select 'dELA' from the
alarm menu and press Pwhich will reveal the
existing delay. Each digit of the delay can be
adjusted using the Up and Down push-buttons,
and the Pbutton to move to the next digit. When
the required delay has been entered, press E to
return to the alarm menu.
9.2.10 Alarm silence time: SIL
This function is primarily intended for use in small
installations where the alarm output directly
operates an annunciator such as a sounder.
When the alarm silence time is set to any figure
other than zero, the Ppush-button becomes an
alarm accept button. After an alarm has occurred,
operating the Pbutton will cause the alarm output
to revert to the non-alarm condition for the
programmed alarm silence time The display will
continue to indicate an alarm after it has been
accepted and silenced.
The alarm silence time may be adjusted between 0
and 3600 seconds in 1 second increments.
To adjust the alarm silence time select 'SIL' from
the alarm menu and press Pwhich will reveal the
existing time. Each digit can be adjusted using the
Up and Down push-buttons, and the Pbutton to
move to the next digit. When the required time has
been entered press E to return to the alarm menu.
9.2.11 Access Setpoint: AcSP
This function controls a separate menu which
provides direct access to the alarm setpoints when
the indicator is in the display mode. See section
9.2.12 for a full description. An operator may
therefore adjust the alarm setpoints without having
access to the programme and alarm menus.
Further protection is provided by a separate
security code.
This direct access menu is enabled and a separate
security code entered from the 'AcSP' function in
the programme menu as shown in Fig 11. To
change the menu parameters select 'AcSP' from
the programme menu and press Pwhich will
display the enable prompt 'EnbL'. Press Pagain to
reveal if the direct access menu is 'On' or 'OFF'.
The Up or Down buttons will toggle the display
between the two conditions.
If 'OFF' is selected, the operator will not have
access to the setpoints from the display mode.
Return to the 'AcSP' prompt in the main menu by
pressing E twice.
If 'On' is selected, the operator will have direct
access to the alarm setpoints from the display
mode via a separate optional security code. To
define the four digit numerical code press Pto
return to the 'Enbl' prompt followed by the Up or
Down button to select the access code prompt
'AcCd'. Pressing P will reveal the current security
code. Each digit of the code may be changed by
operating the Up and Down push-buttons, and the
Pbutton to move to the next digit. When the
required code has been entered, press Etwice to
return to the 'AcSP' prompt in the Programme
Menu.
Code 0000 will disable the security code allowing
direct access to the setpoints by pressing the P
and Up buttons simultaneously.
New instruments with alarms are supplied with this
function disabled and the security code set to 0000

20
9.2.12 Adjusting alarm setpoints from the
display mode
Access to the alarm setpoints from the indicator
display mode is obtained by operating the Pand
Up push-buttons simultaneously as shown in Fig
12. If the setpoints are not protected by a security
code the alarm setpoint prompt 'SP1' will be
displayed. If the setpoints are protected by a
security code, 'COde' will be displayed first.
Pressing Pagain will enable the alarm security
code to be entered digit by digit using the Up and
Down buttons to change the flashing digit, and the
Ppush-button to move to the next digit.
If the correct code is entered pressing Ewill cause
alarm setpoint prompt 'SP1' to be displayed.
Pressing the Up or Down button will toggle the
display between the two alarm setpoint prompts
'SP1' and 'SP2'.
If an incorrect security code is entered, or a button
is not pressed within ten seconds, the instrument
will return to the display mode.