BEKA BA324ND User manual

Issue: 7
4th March 2014
BA324ND
Type nL certified
loop-powered
4½ digit field
mounting indicator
Issue 7
Only for replacement use after May 2013.
Use BA324NE for new applications

2
1. Description
2. Operation
2.1 Controls
3. Type n Certification
3.1 Certificate of conformity
3.2 ATEX certificate
3.3 4/20mA input
3.4 Zones, gas groups & T rating
3.5 Certification label information
4. System Design for Zone 2
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 P push-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 Type n certification
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 backlights
9.5.1 Separately powered backlight
9.5.2 Loop powered backlight
9.6 External switches
9.7 Pipe mounting kits
9.8 Stem mounting kit
CONTENTS
The BA324ND is CE marked to show compliance with the European Explosive Atmospheres
Directive 94/9/EC and the European EMC Directive 2004/108/EC

3
1. DESCRIPTION
The BA324ND is a 4½ digit Ex nL certified 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 is
required. Housed in a robust IP66 glass reinforced
polyester (GRP) enclosure with an armoured glass
window the BA324ND is suitable for installation in
most industrial environments
The BA324ND is a third generation instrument
which, although having additional features
including a separate terminal enclosure and ATEX
certification, remains functionally compatible with
the original BA324N and BA324NC.
The main application of the BA324ND is to display
a measured variable or control signal in a Zone 2
hazardous 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 BA324ND has been issued with a Certificate
of Conformity to BS EN50021:1999, Type of
protection 'nL' by ITS Testing and Certification Ltd.
In addition, the BA324ND complies with the
European ATEX Directive 94/9/EC for Group II,
Category 3G equipment.
2. OPERATION
Fig 1 shows a simplified block diagram of a
BA324ND. 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 BA324ND
2.1 Controls
The BA324ND 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.
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.

4
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. TYPE 'nL' CERTIFICATION
3.1 Certificate of Conformity
ITS Testing and Certification Ltd. (formerly ERA
Technology Ltd) has issued a Certificate of
Conformity Ex99Y4004 confirming that the
BA324ND complies with the CENELEC standard
BS EN50021:1999. This European standard
specifies the requirements for the construction,
testing and marking of Group II electrical apparatus
with type of protection 'n' intended for use in Zone
2, where an explosive atmosphere of gas is
unlikely to occur, or if it does occur will be
infrequent or remain for short periods only.
3.2 ATEX certification
The BA324ND complies with the European ATEX
Directive 94/9/EC for Group II, Category 3G
equipment. It has been assessed using the
'Internal Control of Production' procedure specified
in Annex 8 of the Directive. A technical dossier
has been prepared and an EC Declaration of
Conformity BEKA00ATEX0010 has been issued.
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 which conform
with BS EN60079:Part 14 Electrical Installation in
Hazardous Areas. When designing systems for
installation outside the UK, the local Code of
Practice should be consulted.
3.3 4/20mA input terminals
Input terminals 1 and 3 may be safely connected in
series with any 4/20mA loop providing that in
normal operation the input current to the indicator
(Ii) does not exceed 30mA dc.
3.4 Zones, gas groups and T rating
The BA324ND has been certified as Group II,
Category 3G Ex nL IIC T5 apparatus with a Tamb
of -20 to 60°C.
'L' indicates that the BA324ND uses an energy-
limiting technique to achieve compliance as
defined in EN 60079-15. This technique is based
on the philosophy of intrinsic safety which limits the
current and voltage applied to components which
may generate a spark in normal operation. e.g.
switches and potentiometers.
These approvals confirm that the BA324ND is 'safe
in normal operation' and may be:
Installed in a Zone 2 hazardous area
Used at ambient temperature between
-20 and +60°C
Used with gases in groups:
Group A propane
Group B ethylene
Group C hydrogen
Used with gases having a temperature
classification of:
T1 450°C
T2 300°C
T3 200°C
T4 135°C
or T5 100°C
This allows the BA324ND indicator to be installed
in Zone 2 low risk hazardous areas, and to be
used with most common industrial gases.
3.5 Certification Label Information
ATEX certification information is shown on a label
fitted in a recess on the top outer surface of the
enclosure. Non European certification information
may also be included. The instrument serial
number and date of manufacture are shown on a
separate label inside the terminal compartment.

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4. SYSTEM DESIGN FOR ZONE 2
4.1 Transmitter loops
A BA324ND indicator may be connected in series
with almost any 4/20mA current loop and
calibrated to display the measured variable or
control signal in engineering units.
Fig 2 illustrates a typical application in which a
BA324ND indicator is connected in series with a 2-
wire transmitter and controller.
There are two basic design requirements:
1. In normal operation the voltage and
current applied to the terminals 1 and
3 of the BA324ND must not exceed:
Ui = 4V dc
Ii = 30mA
Providing the maximum input current
in normal operation is less than 30mA,
the maximum voltage between the
indicator terminals will automatically
be limited by the internal safety
components.
2. The 4/20mA loop must be able to
tolerate the additional 1.1V required to
operate the indicator.
Fig 2 BA324ND in a transmitter loop
In practice it is only necessary to ensure that in
normal operation the maximum current flowing in
the loop is less than 30mA.. In the example
shown in Fig 2 this current is determined by the
maximum current from the transmitter.
Considering the example shown in Fig 2, the sum
of the maximum voltage drops of all the
components in the loop must be less than the
minimum power supply voltage.
Minimum operating voltage of 2-wire Tx 10.0
Maximum voltage drop caused by controller 5.0
Maximum voltage drop caused by BA324ND 1.1
Maximum voltage drop caused by cables 0.4
---------
16.5V
Therefore at 20mA the power supply in this
example must have an output greater than 16.5V
4.2 Remote indication
The BA324ND indicator may be driven from any
4/20mA signal to provide remote indication. Fig 3
shows a typical application in which the output
from a gas analyser drives a BA324ND. Again it is
necessary to ensure that the loop complies with
the two design requirements listed in
section 4.1

6
Fig 3 Remote indication
5. INSTALLATION
5.1 Location
The BA324ND indicator is housed in a robust IP66
glass reinforced polyester (GRP) enclosure
incorporating an armoured glass window and
stainless steel fittings. This makes 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 BA324ND 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
BA324ND 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 at one point in the safe area.
The BA324ND 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
an Ex n or Ex e cable gland or conduit entry.
If more than one entry is required, replace
one or both IP66 stopping plugs with an
Ex n or Ex e cable gland or conduit entry.
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.
Fig 4 BA324ND installation procedure

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5.3 EMC
The BA324ND 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 BA324ND earth terminal to a local
earth, or to a cable screen which is earthed in the
safe area.
Fig 5 Dimensions and terminal connections
6. PROGRAMMING & CALIBRATION
The BA324ND is programmed and calibrated via
four push-buttons which are located behind the
instrument control cover.
CAUTION!
The four push-buttons are energy
limited and will not cause ignition in
normal operation. Ex 'n' certification
requires that the instrument enclosure
provides IP54 protection, the control
cover may therefore only be removed
for calibration when there is no
possibility of dust or water ingress.
Before replacing the cover ensure that
the sealing gasket is undamaged and
free from dirt and foreign bodies.
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. These push-buttons
are energy limited and may be operated when a
flammable atmosphere is likely to be present.
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. Por 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.

8
If the correct code has been entered pressing E
will 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 BA324ND 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
Display Description of function
'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
'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 effects the indicator display.
See section 6.7.1

9
Display Description of function
'rEF' Calibration of internal references
The indicator contains two references
representing a 4 and 20mA. input
These enable the BA324ND 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
'C - - P' Function of P push-button
The BA324ND 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
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 Ebutton 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 BA324ND 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 Pwhich 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.

10

11
When all the digits have been adjusted, press Eto
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 Pwhich 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 Eto
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 Pagain 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 Eto return to the 'SPAn' prompt followed by
Eto return to the menu.
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 Pagain will
give access to the sub-menu, or pressing Ewill
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
Ppush-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 Ebutton
will return the indicator to the main menu.

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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 P push-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 Pwhich 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 Eto 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.
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.

13
7. CALIBRATION EXAMPLES
The following examples illustrate the two ways in
which a BA324ND indicator may be calibrated.
7.1 Using an external current source
The BA324ND 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 Pand E. The indicator will
respond by displaying 'COdE'. Press
Pto clear this prompt and set the
display to the security code 1209
using the Up, Down and Ppush-
buttons. Pressing Ewill 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.
Step 5 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
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 Pand the
indicator will request a 4mA input by
displaying 'ZErO'. Set the input
current to 4.0000 ± 0.0004mA and
press Pagain which will reveal the
existing zero display. Using the Up,
Down and Ppush-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.

14
7.2 Using the internal references
As in 7.1 the BA324ND 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 P push-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 Pand E. The indicator will
respond by displaying 'COdE'. Press
Pto clear this prompt and set the
display to the security code 1209
using the Up, Down and Ppush-
buttons. Pressing Ewill 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 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.
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.
Using the Up, Down and Ppush-
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 Pto 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.

15
8. MAINTENANCE
8.1 Fault finding during commissioning
If a BA324ND 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.
(5V between terminals 1
& 13 if a loop powered
backlight is fitted)
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
CAUTION!
ENSURE PLANT SAFETY BEFORE
STARTING MAINTENANCE
Live maintenance should only be
performed when there is no risk of a
flammable atmosphere being present,
and dust or water can not enter the
enclosure Before replacing control
and terminal covers ensure that the
sealing gaskets are undamaged and
free from dirt and foreign bodies.
If a BA324ND 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.

16
8.3 Servicing
CAUTION!
ENSURE PLANT SAFETY BEFORE
STARTING MAINTENANCE
Live maintenance should only be
performed when there is no risk of a
flammable atmosphere being present,
and dust or water can not enter the
enclosure. Before replacing control
and terminal covers ensure that the
sealing gaskets are undamaged and
free from dirt and foreign bodies.
We recommend that faulty instruments and
assemblies are returned to BEKA associates or to
our local agent for repair.
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 and mechanical
condition 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.

17
9. ACCESSORIES
9.1 Units of measurement and instrument
identification
All BA324ND indicators are fitted with a blank
escutcheon around the liquid crystal display. This
escutcheon 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. Before
re-assembling the instrument ensure that all the
sealing gaskets are undamaged and free from dirt
and foreign bodies.
The BA324ND can also be supplied with a blank or
custom engraved stainless steel plate secured to
the instrument terminal cover by two screws.
9.2 Alarms
The BA324ND 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 BA324ND display
alternates between the measured value and an
alarm identification.
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

18
9.2.2 Type nL certification
Each of the two alarm is a galvanically isolated
single pole solid state switch which has been
certified as a separate Ex nL Group II, Category
3G circuit.
The input safety parameters for each alarm are:
Ui 30V dc
Ii 100mA
Pi 0.2W
This allows each alarm output to switch any dc
circuit providing that in normal operation the
maximum supply voltage is not greater than 30V,
and the current is not greater than 100mA. Pi will
automatically be limited to less than 0.2W by the
safety components within the indicator.
Fig 10 shows an typical application in which a
BA324ND is displaying the output from a 2-wire
transmitter in Zone 2. Alarm 1 is controlling a
solenoid valve and alarm 2 a sounder in the safe
area.
Fig 10 Typical alarm application
9.2.3 Programming and adjustment
When an alarm card is added to a BA324ND 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
'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

19
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 Eto 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.

20
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.
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 Eto 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.