BEKA BA526C User manual

Issue: 9
1st June 2017
Alarm
setpoints
Digital
display
Label
information
Alarm
annunciators Push
buttons
Analogue
display
BA526C
loop-powered
analogue
bargraph and
digital indicator
issue 9

2
1. Description
2. Operation
2.1 Controls
3. Applications
3.1 Transmitter loops
3.2 Remote indication
4. Installation
4.1 Location
4.2 Installation procedure
4.3 EMC
5. Programming and Calibration
5.1 Summary of programmable
functions
5.2 Root extractor
5.3 Digital display
5.4 Digital resolution
5.5 Dummy trailing zero
5.6 Position of decimal point
5.7 Bargraph display
5.8 Calibration using an external
current
source.
5.9 Calibration using internal
references
5.10 Conditioning sub-menu
5.10.1 AC rejection
5.10.2 Calibration of internal
references.
5.11 Function of the Ppush-button
5.12 Null display function
5.13 Security code
5.14 Over and under-range
6. Calibration Examples
6.1 Using an external current source
6.2 Using the internal references
7. Maintenance
7.1 Fault finding during commissioning
7.2 Fault finding after commissioning
7.3 Servicing
7.4 Routine maintenance
7.5 Guarantee
7.6 Customer comments
8. Accessories
8.1 Units of measurement and
instrument identification.
8.2 Alarms
8.2.1 Solid state output
8.2.2 Programming and
adjustment
8.2.3 Alarm enable
8.2.4 Setpoint adjustment
8.2.5 Alarm function
8.2.6 Alarm output status
8.2.7 Hysteresis
8.2.8 Alarm delay
8.2.9 Alarm silence time
8.2.10 Display alarm identification
8.2.11 Access setpoint
8.2.12 Adjusting alarm setpoints
from display mode.
8.3 Lineariser
8.3.1 Calibration using an
external
current source.
8.3.2 Calibration using internal
references.
8.4 Display backlight
CONTENTS
The BA326C is CE marked to show compliance with the European EMC Directive 2014/30/EU

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1. DESCRIPTION
The BA526C is a panel mounting loop powered
4/20mA combined bargraph and digital indicator.
The one hundred segment bargraph provides a
quick indication of input current magnitude and
trend, supported by an accurate digital display
which may be calibrated in engineering units.
The BA526C is a second generation instrument
which, although having additional functions,
remains compatible with the original BA526B.
The main application of the BA526C is to display a
measured variable or control signal in a process
area. The zero and span of the digital display are
independently adjustable so that the indicator may
be calibrated to display any 4/20mA variable in
engineering units. The analogue display shows
the 4/20mA input on a single or double 100
segment bargraph which may be fitted with a
custom scale to indicate the units of measurement.
Both the bargraph and digital display may be offset
to indicate deviation from a specified input current.
The indicator is housed in a robust 144 x 48 panel
mounting DIN enclosure with an IP65 sealed front.
2. OPERATION
Fig 1 shows a simplified block diagram of a
BA526C. 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.
Fig 1 Simplified block diagram of BA526C
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.
Negative signs For 3 seconds.
cycled
Input current Using calibration
display in information stored in
engineering instrument memory.
units.

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2.1 Controls
The BA526C is controlled and calibrated via four
front panel push-button switches. In the display
mode i.e. when the instrument is displaying a
4/20mA input current, these switches have the
following functions:
PWhile this button is pushed the digital
display will show the input current in
mA, or as a percentage of the
instrument span depending upon how
the instrument 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 either alarm is enabled.
Down While this button is pushed the digital
display will show the calibration with a
4mA input. When released the normal
display in engineering units will return.
Up While this button is pushed the digital
display will show the calibration with a
20mA input. When released the
normal displays in engineering units will
return.
ENo function in the display mode.
3. APPLICATIONS
3.1 Transmitter loops
A BA526C indicator may be connected in series
with almost any 4/20mA current loop that can
tolerate the 1.1V drop required to operate the
instrument (increases to 1.2V at -20ºC), and be
calibrated to display the measured variable or
control signal in engineering units.
Fig 2 illustrates a typical application in which a
BA526C indicator is connected in series with a
2-wire transmitter.
Fig 2 BA526C in a transmitter loop
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.
Therefore at 20mA the power supply in this
example must have an output greater than 16.6V
Minimum operating voltage of 2-wire Tx 10.0
Maximum voltage drop caused by controller 5.0
Maximum voltage drop caused by BA526C 1.2
Maximum voltage drop caused by cables 0.4
______
16.6V

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3.2 Remote indication
A BA526C may be driven from any 4/20mA signal
to provide a remote indication. Fig 3 shows a
typical application in which the output from a gas
analyser drives a BA526C. Again it is necessary
to ensure that the voltage capability of the 4/20mA
gas analyser output is greater than the sum of the
voltage drops introduced by the BA526C and the
cable resistance.
Fig 3 Remote indication
4. INSTALLATION
4.1 Location
The BA526C indicator is housed in a robust
aluminium enclosure with an armoured glass
window surrounded by a Noryl bezel. The front of
the instrument provides IP65 protection, and a
gasket seals the joint between the instrument
enclosure and the panel. The instrument may be
installed in any panel providing the environmental
limits shown in the specification are not exceeded.
Fig 4 shows the overall dimensions of the BA526C
and panel cut-out. To achieve an IP65 seal
between the instrument enclosure and the panel
the smaller cut-out must be used and the
instrument secured with four mounting clips.
The BA526C liquid crystal display has maximum
contrast when viewed from directly ahead and
slightly below the centre line of the instrument.
For reflective displays there is very little
degradation of contrast when viewed from above
the centre line, but slight degradation may be
noticeable when the instrument is fitted with a
backlight.
Fig 4 BA526C dimensions

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4.2 Installation Procedure
Fig 5 illustrates the instrument installation
procedure.
a. Insert the BA526C into the instrument panel
from the front of the panel.
b. Fix panel mounting clips to the sides of the
BA526C and tighten until the instrument is
secure - see Fig 5. Recommended torque
22cNm (1.95 ldf in). Do not over tighten. If
an IP65 seal is required between the
enclosure and the instrument panel, four
panel mounting clips must be used.
c. Connect the panel wiring to the rear terminal
block(s) as shown in Fig 5. To simplify
installation the terminals are removable so
that the wiring can be completed before the
instrument is installed.
Fig 5 Installation and terminal connections
4.3 EMC
The BA526C complies with the requirements of the
European EMC Directive 2014/30/EU. For
specified immunity all wiring should be in screened
twisted pairs, with the screens earthed at only one
place. The indicator enclosure may be earthed
locally by putting a tag under one of the rear panel
fixing screws.
5. PROGRAMMING & CALIBRATION
The BA526C is programmed and calibrated via
four front panel push-buttons. 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 5.1 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, it is recommend that at
least the summary of the programmable functions
in section 5.1 is read before attempting
programming or recalibration.
When the indicator is fitted with linearisation, the
basic menu is expanded to include additional
functions. All the optional accessories are
described in section 8 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. If the
correct code has been entered pressing Ewill
cause the first parameter 'root' to be displayed. If
an incorrect code or no entry is made the indicator
will return to the display mode.

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Once within the programme 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
minus signs for a few seconds while the new
information is stored in permanent memory.
All new BA526C indicators are supplied calibrated
as requested at the time of ordering. If calibration
is not requested, the digital indicator will be
calibrated to display 0.00 to 100.00 for 4 to 20mA
input.
5.1 Summary of programmable functions
This section summarises all of the programmable
functions and when read with Fig 6 provides
sufficient information to condition and calibrate the
indicator. A cross-reference to a more detailed
description 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'.
See section 5.2
'dSPL' Digital display
Turns the 4½ digit display 'On' or 'OFF'.
See section 5.3
'rESn' Display resolution & dummy zero
Selects the resolution of the least
significant display digit. May be set to
1, 2, 5 or 10 digits.
See section 5.4
'dZErO' Dummy trailing zero
Activates a dummy zero after the 4½
digit display so that larger number may
be displayed.
See section 5.5
'd.P.' Decimal point
Positions a dummy decimal point
between any of the digits or turns it off.
See section 5.6
Display Description of function
'bAr' Bargraph display
Selects a column or single segment
display, and defines whether the input
current is displayed on the left hand or
on both 100 segment bargraphs.
See section 5.7
'CAL' Calibration of displays using
external current source.
Enables the zero and span of the
digital indicator to be adjusted using an
external current source such as a
calibrator. The analogue bargraph is
linked to the digital display and is
automatically calibrated at the same
time.
When performed with an accurate
traceable current source, this is the
preferred method of calibration.
See section 5.8
'SEt' Calibration of display using internal
references.
Enables the zero and span of the digital
indicator to be adjusted without the
need for an accurate input current or
disconnection from the 4/20mA loop.
The analogue bargraph is linked to the
digital display and is automatically
calibrated at the same time.
See section 5.9
'Cond' Indicator conditioning
This function provides access to a
password protected sub-menu enabling
the internal references to be calibrated,
and the mains (line) frequency rejection
to be selected.
See section 5.10
CAUTION
Do not attempt to change the
frequency of the mains (line) filter
frequency or recalibrate the internal
references without reading section
5.10 of this manual

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Display Description of function
'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 5.10.1
'rEF' Calibration of internal
references
The indicator contains two references
representing 4 and 20mA. These
internal references are used when the
indicator display is calibrated without
an external current calibrator, and
when the input current is displayed in
milliamps. See the SEt and C--P
functions. If either of these functions is
to be used, the internal references
should be periodically calibrated.
See section 5.10.2
'C - - P' Function of P push-button
The BA526C digital indicator may be
programmed to display the input
current in milliamps or the input current
as a percentage of the displayed span
when the Ppush-button is operated.
See section 5.11
'null' Null display function
When activated the null function
enables both displays to be zeroed at
any input current to produce a deviation
display.
See section 5.12
'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 5.13
5.2 Root extractor: root
This function is primarily intended for use with
differential flowmeters which have a square law
output. The root extractor linearises the input
current between 4.04mA and 20mA (5 to 100%
flow) so that the flow signal is displayed in linear
units. For inputs below 4.04mA the BA526C
displays zero. To activate the square root extractor
select 'root' from the menu and press Pwhich 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 Ebuttontoreturntothe
main menu.
For reference, the following table shows the output
current from a non-linearised differential flowmeter.
% 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
5.3 Digital display: dSPL
When only an analogue display is required or
when the instrument is mounted horizontally the
digital display may be disabled. To change the
status of the digital display select 'dSPL' from the
main menu and press Pwhich will show if the
digital display is 'On' or 'OFF'. If 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.
5.4 Display resolution: rESn
This function defines the resolution of the display
digit but does not effect the bargraph. Decreasing
the display resolution can improve the readability
of a noisy signal. Select 'rESn' from the menu and
press Pwhich will reveal the current display
resolution. To change the resolution press the Up
or Down button to select 1, 2, 5 or 10 digits. When
the required resolution is shown press Eto return
to the main menu.

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5.5 Dummy trailing zero: dZErO
The BA526C digital display can show any number
between -19999 and 19999. If a larger number is
required a trailing dummy zero can be activated
which extends the display range from -19990 to
99990 The last digit is a dummy so the maximum
resolution is 10 digits i.e. the last digit is always 0.
To change the status of the trailing dummy zero
select 'dZErO' from the main menu and press P
which will reveal if the dummy zero is 'On' or 'OFF'.
If the function is set as required, press Eto return
to the main menu, or press the Up or Down button
to change the setting, followed by the Ebutton to
return to the main menu.
After activating the dummy trailing zero, care
should be taken to ensure that the digital display
does not overrrange.
5.6 Position of the decimal point: d.P.
A dummy decimal point can be positioned between
any of the digits, including the dummy trailing
zero, 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 main menu.
5.7 Bargraph display: bAr
This function enables the 4/20mA input to be
displayed as a column or a single segment on one
or both of the 100 segment bargraphs. When
optional alarms are fitted the right hand bargraph
always displays the alarm setpoints.
To change the bargraph display parameters select
'bAr' from the main menu and press Pwhich will
reveal if the BA526C is programmed to display a
column 'Col' or a single segment 'SEg'. The
setting can be changed by pressing the Up or
Down buttons. Pressing Pagain will show if the
BA526C is programmed to display the input
current on both bargraphs 'dUAL' or on just the left
hand bargraph 'SnGL'. Again pressing the Up or
Down buttons will change the setting. At any point
in the procedure pressing the Ebutton will return
the instrument to the main programme menu.
5.8 Calibration using an external
current source: CAL
This function enables the zero and span of the
digital display to be adjusted using an external
calibrated current source. When used with an
accurate traceable current source this is the
preferred method of calibration.
The analogue bargraph is automatically calibrated
when the digital display is calibrated, therefore no
separate adjustments are required. Fig 7 shows
the analogue display resulting from various digital
display calibrations.
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, except the dummy zero if
activated, 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 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
digital 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,
except the dummy zero if activated, 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 level to current converter.

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5.9 Calibration using internal references:
SEt
This function enables the zero and span of the
digital 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 5.10.2
The analogue bargraph is automatically calibrated
when the digital display is calibrated, no separate
adjustments are required. Fig 7 shows the
analogue display resulting from various digital
display calibrations.
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, except the dummy zero if
activated, 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 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 of the display, except the dummy zero
when activated, 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 E
to return to the menu.
5.10 Conditioning sub-menu: Cond
This is a password protected sub-menu which
allows the mains (line) frequency at which the
indicator has maximum ac rejection to be selected,
and the two internal references to be calibrated.
To gain access to the sub-menu select 'Cond' from
the main menu and press P. The indicator will
display '0000'. Using the Up and Down buttons and
the P button to move to the next digit
enter the password 'SurE'. (Note that 'S' is entered
as '5'). Pressing Ewill then give access to the two
functions in the sub-menu.
5.10.1 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
toggled between the two options by pressing the
Up or Down buttons. When set as required press
the Ebutton to return to the sub-menu.
5.10.2 Calibration of internal references:
rEF
CAUTION
Do not attempt to recalibrate these
references unless you have adequate
test equipment and have read the
following instructions.
The indicator contains two references representing
4 and 20mA. These references are used in the
'SEt' function which enables the indicator displays
to be calibrated without an external current
calibrator. They are also used in the 'C--P'
function if the instrument is programmed to display
the input current when the Ppush-button is
operated. If the 'SEt' or 'C--P' functions are not
used, it is not necessary to calibrate these
internal references.
To calibrate the references connect the instrument
to an accurate 4/20mA current source and select
'rEF' from the sub-menu . Press Pwhich will result
in a '.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

11

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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 tto
the '.020A' prompt. Two operations of the Ebutton
will return the indicator display to 'Cond' in 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 indicator has 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.
5.11 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 digital display will
show the input current in milliamps, or the input
current as a percentage of the span. The
analogue display continues to operate normally
while the Pbutton is operated.
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 5.10.2
The function of the Ppush-button changes when
either or both alarms are enabled.
5.12 Null display function: null
This function enables the BA526C analogue
bargraph to operate as a deviation indicator
displaying the difference between the input current
and a specified reference.
To activate this function select 'null' from the main
menu and press P. Pressing the Up or Down
button will toggle the function between 'OFF' and
'On', when set as required press Eto return to the
main menu.
Fig 7 Configuration of anolouge bargraph

13
To define the input about which deviation is to be
displayed the BA526C must be returned to the
display mode. With the instrument displaying the
required input reference, press the Down and E
buttons simultaneously. The BA526C will respond
by displaying 'null' for a few seconds, after which
the reference input will be automatically subtracted
from both the analogue and digital displays.
Starting at the reference point, the bargraph will
display a column extending upwards or
downwards to indicate the difference between the
input and the reference. Fig 8 illustrates the
display resulting from nulling a BA526C calibrated
to display 0 to 1000 at 500 (12mA) and 250 (8mA).
To prevent accidental or unauthorised access the
null function can only be used once. If the
reference point needs to be changed, the null
function must be turned off and then back on from
the main programme menu.
To prevent inadvertent alarm setpoint changes, the
null function can not be operated if either of the
optional alarms are enabled. If alarms are
required, they must be enabled after the null
function has been used.
Fig 8 Effect of nulling at two different inputs
5.13 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 original 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 terminal block(s) by gently pulling.
Unscrew the six screws securing the rear panel,
and lift off the panel which will reveal the link as
shown in Fig 9.

14
Fig 9 Location of security code override link
5.14 Over and under-range
If the range of the digital display 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.
The bargraph displays an upward pointing arrow
when overrange occurs and a single negative
segment and the zero bar for underrange.
If the instrument input current falls below 3mA the
initialisation sequence is performed as described
in section 2.
6. CALIBRATION EXAMPLES
The following examples illustrate the two ways in
which a BA526C indicator may be calibrated.
6.1 Using an external current source
The BA526C indicator is required to display:
0.0 with a 4mA input
1500.0 with a 20mA input
from a linear level transducer. Maximum display
resolution is required, the frequency of the local
mains 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 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.

15
Step 4 Select frequency of max rejection
Scroll though the main menu until 'Cond'
is displayed and press P. The indicator
will display the prompt 'SurE' which is a
warning that changing the parameters in
this sub-menu will change the instrument
calibration. To enter the 'FrE' sub-menu
press P, and then again to reveal the
frequency of maximum rejection. Select
'50' Hz using the Up or Down buttons,
and finally return to the main menu via
the 'FrE' prompt by pressing Etwice.
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.Usingthe
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 digital 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 000.0 Press
Eto return to the 'ZErO' prompt. The
indicator will display 'Ent' while storing
this figure.
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 1500.0
Press Etwice to return to the main
menu. The indicator will display 'Ent'
while storing this figure.
The analogue bargraph will be
automatically calibrated to display 0
with 4mA input and full scale with 20mA
input.
Step 8 Return to the display mode
Following completion of calibration
return to the display mode by pressing
'E'.
6.2 Using the internal references
As in 6.1 the BA526C is required to display:
0.0 with a 4mA input
1500.0 with a 20mA input
from a linear level transducer. Maximum display
resolution is required, the frequency of the local
mains 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 Pand 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.

16
Step 3 Select frequency of max 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 Etwicetoreturntothemain
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.UsingtheUp 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 digital 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 000.0
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 1500.0 Press Eto return to
the 'SPAn' prompt. Press Eagain to
return to the main menu.
The analogue bargraph will be
automatically calibrated to display 0
with 4mA input and full scale with 20mA
input.
Step 7 Return to display mode
Following completion of calibration
return to the display mode by pressing
'E'.
7. MAINTENANCE
7.1 Fault finding during commissioning
If a BA526C 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
between no power loop.
terminals supply.
1 and 3.
Insufficient Check supply
loop voltage voltage and
to operate voltage drops
indicator caused by all
components in the
loop.
Indicator Positive The indicator has
displays 1 over-range been incorrectly
calibrated & is trying
to display a number
greater than 19999,
or input current is
greater than
approximately 1mA.
Indicator Negative The indicator has
displays -1 0ver-range incorrectly calibrated
& is trying to display
a number less than
-19999, or the input
current is less than
approximately
3.5mA.
Unstable 4/20mA input Check loop supply
display has a large voltage.
ripple content.
Unable to Incorrect Enter correct
enter the security security code or fit
programme code security link in
mode entered. override position
See Fig 9.

17
7.2 Fault finding after commissioning
ENSURE PLANT SAFETY BEFORE
STARTING MAINTENANCE
If a BA526C fails after it has been functioning
correctly, the following procedure should be
followed:
Symptom Cause Solution
No display No power Check that a current
and no volts supply is flowing in the
between loop.
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.
7.3 Servicing
All standard BA526C indicators are
interchangeable, and a single spare may be used
to replace any instrument which fails.
We recommend that faulty instruments are
returned to BEKA associates or to our local agent
for repair.
7.4 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.
7.5 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.
7.6 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.
8. ACCESSORIES
8.1 Units of measurement and instrument
identification
All BA526C indicators are fitted with a display label
behind the armoured glass window. This label can
be supplied with any analogue scale graduations,
units of measurement and applicational information
specified at the time of ordering. Replacement
printed labels can be fitted on-site providing the
following precaustions are observed, but we
strongly recommend that instruments are returned
to the factory or our local agent for the
replacement label to be fitted.
CAUTION
a. Only open enclosure in a clean environment.
b. Observe ESD precautions i.e. operator
should be earthed (grounded).
To gain access to the display label un-plug the
instrument terminal block(s) by gently pulling and
remove the rear panel which is secured by six
screws - see Fig 9. The electronic assembly may
then be pulled out of the enclosure to reveal the
display label. If a new analogue scale is being
fitted, it is recommended that the instrument is
activated so that the scale can be accurately
aligned with the display.
If specified at the time of ordering, the BA526C can
be supplied with tag or applicational information
printed onto the instrument certification label which
is located on the side of the enclosure. The
following can be accommodated:
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

18
8.2 Alarms
All BA526C indicators include dual alarm functions,
which may be used to show acceptable operating
limits, but alarm outputs are only fitted when the
alarm option is specified at the time of purchase.
The two solid state single pole alarm outputs may
be independently programmed as high or low
alarms with normally open or closed outputs.
Fig 10 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.
CAUTION
Alarm outputs should not be used for
critical safety applications such as a shut
down system.
Fig 10 Alarm outputs
When one or both of the alarms is enabled, the
right hand analogue bargraph indicates the
position of the alarm setpoint(s) so they can be
easily compared with the measured value. The
type of setpoint display depends upon alarm
conditioning and the relative values of the two
setpoints.
When alarm 1 is programmed as a low alarm and
alarm 2 as a high alarm, the display shown in Fig
11A will be produced providing setpoint 1 is less
than setpoint 2. If the low setpoint (1) is greater
than the high setpoint (2), or the function of the
alarms is reversed, the setpoints will be indicated
by two single segments on the right hand bargraph
as shown in Fig 11B.
If only one alarm is enabled the setpoint will be
indicated by a column extending from the setpoint
to the top of the display for a high alarm, and from
the setpoint to the bottom of the display for a low
alarm.
Fig 11A Set point display
Fig 11B Display with set points reversed

19
Annunciators above the digital display show the
status of both alarms, and the digital display can
be programmed to alternate between the
measured value and an alarm identification.
Programmable functions for each alarm include
adjustable setpoint, hysteresis, alarm delay and
alarm accept. When frequent setpoint changes
are required, a separate menu provides direct
access to both setpoints from the display mode
without giving the operator access to the
programme and alarm menus. A different security
code may be included to prevent tampering or
accidental adjustment.
8.2.1 Solid state output
Each alarm has a galvanically isolated single pole
solid state switch output as shown in Fig 12. The
outputs are polarised and current will only flow in
one direction. Terminal 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 12 Equivalent circuit of each alarm output
Fig 13 Typical alarm application
Fig 13 shows a typical application for the BA526C
indicator with alarms. A solenoid valve is
controlled by one alarm output, while the second
alarm output operates a sounder.
8.2.2 Programming and adjustment
When an alarm card is added to a BA526C the
main programme menu is extended as shown in
Fig 14. The additional functions appear between
'Cond' and 'C--P' in the main menu. For simplicity
Fig 14 only shows the additional functions
available on alarm 1, but alarm 2 has identical
facilities.
The following table summaries 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

20
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 8.2.3
'SP1' Alarm setpoint 1
Adjusts the alarm setpoint. The alarm
is activated when the indicator display
equals the setpoint.
See section 8.2.4
Display Description of function
'HI.LO' Alarm function
Defines whether the alarm has a high
or low function
See section 8.2.5
'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 8.2.6
'HStr' Hysteresis
Adjusts the alarm hysteresis.
See section 8.2.7
P P E
ALr2
E
As ALr1
AcSP
P
E
E
EnbL
On
PE E P
Cond ALr1
E E
0000
AcCd
C - - P
E
E
AlarmsMain menu Main menu
Access Enable
or
to toggle
between
On and OFF
Security Code
For Direct
Access to
Setpoints
Enter code by
pressing
and
to move to
next digit
Code 0000
allows direct
access
P
Access to setpoints from display mode
OFF
EnbL
PE
Alarm Enable
or
to toggle
between
On and OFF
E
SP1
00.00
PE
E
Setpoint
Enter by
pressing
and
to move to
next digit
P
High or Low
Alarm
or
to toggle
between
HI and LO
E
HI.LO
LO
PE
Normally Open
or Closed
Output
or
to toggle
between
no and nc
E
no.nc
nc
PE
E
HStr
00.00
PE
Hysteresis
Enter by
pressing
and
to move to
next digit
Not available
for total alarms
P
E
dELA
0000
PE
Alarm Delay
Enter by
pressing
to move to
next digit
P
and
E
0000
PE
SIL
Alarm Silence
Time
next digit
to move to
pressing
Enter by
and P
Display alarm
identification
0000
PE
FLASH
E
or
to toggle
between
On and OFF
Fig 14 Alarm Programme Menu