BEKA BA488C User manual

Issue: 15
22nd October 2020
BA488C
Intrinsically safe
Panel mounting
Modbus RTU display
Serial Data display
Issue 15

1. Description
1.1 Documentation
1.2 Version 3 firmware
1.3 Version 3.4 firmware
2. Operation
3. Applications
3.1 Legacy protocol
3.2 Modbus protocol
3.3 BEKA protocol
4. Intrinsic Safety Certification
4.1 ATEX certificate
4.2 Zones, gas groups and T rating
4.3 Power supply
4.4 External switches
4.5 Switch outputs
4.6 Certification label information
5. System Design for Hazardous Area
5.1 Use with a BA201 Communications
Isolator.
5.1.1 Cable length
5.1.2 Two wire system
5.1.3 Three wire system
5.2 Use with MTL5051 Serial Data Comms
Isolator.
5.2.1 Cable length
5.2.2 Conditioning MTL5051
5.2.3 Two wire system
5.2.4 Three wire system
5.2.5 Four wire system
5.3 Switch outputs
6. Installation
6.1 Location
6.2 Installation procedure
6.3 EMC
7. Configuration
7.1 Default configuration
7.2 Accessing the configuration menus
7.3 Summary of configurable functions
7.4 Quick access menu
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 Tag number
9.2 Serial Text Display - Programming
Guide.
9.3 Serial Text Display – Modbus
Interface Guide.
10. Index
Appendix 1
Getting Started Quickly
Appendix 2
FM Approval for use in the USA and
cFM Approval for use in Canada.
Appendix 3
IECEx certification
2
CONTENTS
The BA488C is CE marked to show compliance with the
European Explosive Atmospheres Directive 94/9/EC
and the European EMC Directive 2004/108/EC

1. DESCRIPTION
The BA488C is an intrinsically safe instrument that
can display text and simple graphics in a
hazardous area. Incorporating six operator push-
buttons, two solid state outputs and a backlit 120 x
64 pixel graphical display, it is a versatile operator
interface for simple machine or process control
applications.
Housed in a robust 72 x 144 panel mounting DIN
enclosure, the BA488C text display has an IP66
front panel and is supplied with a gasket to seal the
joint between the instrument and the panel.
The BA488C text display has been issued with an
EC-Type Examination Certificate by Notified Body
Intertek Testing and Certification Ltd for gas
atmospheres which has been used to confirm
compliance with the European Potentially
Explosive Atmospheres Directive 94/9/EC.
For use in the USA and Canada the instrument has
intrinsic safety and nonincendive FM and cFM
Approval – see Appendix 2.
For international applications the BA488C also has
IECEx certification – see Appendix 3.
1.1 Documentation
This instruction manual describes system design,
conditioning and installation of the BA488C serial
text display. To quickly install and commission a
BA488C for a basic application, please read
Appendix 1 Getting Started Quickly.
For detailed programming information separate
guides describe the Modbus RTU and BEKA
protocols. These are available from our sales
department or may be downloaded from
www.beka.co.uk.
Serial Text Display–Modbus Interface Guide
Description of parameters
Use with standard screens
Serial Text Display–Programming Guide
BEKA protocol
Command summary & reference
Scripting
Pattern matching
Advanced features
1.2 Version 3 Firmware
This manual describes the enhanced features
available in text displays employing version 3.0
firmware which was released in August 2005.
Namely:
Modbus protocol
Cyclic data and mapped variables
Nine tandard screens
Scripting
Pattern matching
Speed increase
Font 5 soft font storage
The instrument’s firmware version can be
established using the ‘Unit Info’ function in the
main configuration menu - see section 7.3 of this
manual. Text displays employing Version 3.0
firmware are backwards compatible with all earlier
versions.
1.3 Version 3.4 Firmware
This manual describes the additional features
available in text displays employing version 3.4
firmware which was released in October 2009.
Namely:
Two eight variable standard screens added.
Integer variables added to the Modbus register
map to complement the original float values.
New function allows the number of process
variables to be entered, so that when scrolling
the display unused screens are not shown.
Enhancements to to the Scripting facility.
The instrument’s firmware version can be
established using the ‘Unit Info’ function in the
main configuration menu - see section 7.3 of this
manual. Text displays employing Version 3.4
firmware are backwards compatible with all earlier
versions.
3

2. OPERATION
Fig 1 shows a simplified block diagram of a
BA488C serial text display. The instrument is
connected to a serial data galvanic isolator in the
safe area via two, three or four wires that carry
both power and bi-directional communication. The
switch outputs may be controlled and the operator
switches interrogated from the safe area via the
serial communication link.
Fig 1 Simplified block diagram of BA488C
Two alternative certified galvanic isolators may be
used to power and communicate with the display.
The BA201 communications isolator has an RS232
or two wire RS485 safe area port and can support
up to to four BA488C displays with serial numbers
above 42518/… i.e. manufactured after Sept.
2007. The MTL5051 serial data comms isolator
has an RS232 or RS422 safe area port and can
support one or two displays, or up to four with the
addition of an MTL5025 solenoid driver. See
section 5 for details.
3. APPLICATIONS
The BA488C has been designed for easy
integration with most serial data sources and
therefore contains a wealth of features. Although
at first sight the complexity may seem daunting,
the support documentation is application related so
that only relevant sections need to be read. If
additional help is needed BEKA engineers are
always willing to assist with system design,
programming and screen development.
The BA488C may be used with three alternative
protocols; legacy, BEKA or Modbus RTU. The
pattern matching function also enables proprietary
ASCII serial data, such as that from a weighing
system, to be decoded and displayed. This
advanced feature is described in the Serial Text
Display – Programming Guide.
Legacy protocol
The legacy protocol contained in the BA488C
allows the instrument to replace an MTL644 IS text
display. All the functions of an MTL644 are
replicated, but with the advantage of a backlit
display and ATEX certification.
Legacy protocol only allows three external
switches S1, S2 & S3, not the front panel push-
buttons, to be used for operator inputs. Similarly,
the MTL644 only has one output control, so the
two switch outputs operate in parallel.
When using the legacy protocol, the configuration
menus are only operational between power being
applied to the BA488C and the first message being
received.
3.2 Modbus RTU protocol
The BA488C supports Modbus RTU protocol in
slave mode. Up to eight process variables,
together with their units of measurement and tag
description may be displayed on one of the eleven
standard screen formats shown below. These
illustrate typical units of measurement and tag
information, but any may be entered. This allows
one, two, four or eight process variables to be
shown on a common screen without the need for
any programming, apart from setting the BA488C
address and writing each Modbus variable in the
required Modbus register address map.
If more process variables than can be shown on
the selected standard screen are to be displayed,
the operator can select which process variables
are shown by operating the Up or Down push-
buttons. This selection can also be made by the
system host.
4

One variable
Two variables
Four variables
Eight variables
One variable + horizontal bargraph
Two variables + horizontal bargraphs
One variable + vertical bargraph
Two variables + vertical bargraphs
Three variables + vertical bargraphs
Four variables + vertical bargraphs
Eight variables + horizontal bargraphs
The Modbus protocol also enables each of the six
front panel push-buttons to be interrogated so they
may be used for operator controls. If larger
industrial size push-buttons are required, these
may be connected to the BA488C terminals.
When external switches are used the instrument
front panel switches are disabled.
The two single pole solid state outputs may be
controlled via Modbus allowing certified hazardous
area loads such as sounders, beacons and valves
to be turned on and off.
For more demanding applications BEKA protocol
may be used to construct custom display screens
for use in a Modbus system.
Modbus protocol is described in the Serial Text
Display – Modbus Guide, which is available from
the BEKA sales office and from the BEKA web site.
5

3.3 BEKA protocol
BEKA protocol enables text to be written anywhere
on the screen in five different font sizes, together
with lines, boxes and bargraphs. Alternatively one
of the nine standard display screens described in
section 3.2 may be used.
Simple bit map graphics may also be downloaded
to the display and all characters can be reversed or
flashed. Information may also be written to a
hidden screen that may be displayed when
required.
This protocol enables each of the six front panel
push-buttons to be interrogated so they may be
used for operator controls. By displaying the
switch function on the screen adjacent to the
button, ‘soft switches’ can be created. If larger
industrial size push-buttons are required, these
may be connected to the BA488C terminals.
When external switches are used the front panel
switches are disabled.
Two single pole solid state outputs may be used to
switch certified hazardous area loads such as
sounders, beacons and valves.
BEKA protocol is described in the Serial Text
Display – Programming Guide which is available
from the BEKA sales office and from the BEKA
web site.
6

4. INTRINSIC SAFETY CERTIFICATION
4.1 ATEX certificate
The BA488C has been issued with EC-Type
Examination Certificate ITS02ATEX2036X by
Notified Body Intertek Testing & Certification Ltd
(ITS). This has been used to confirm compliance
with the European ATEX Directive 94/9/EC for
Group II, Category 1, gas atmospheres,
Ex ia IIC T5 Ga. 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
IEC 60079: Part 14 Electrical installation design,
selection and erection. When designing systems
for installation outside the UK, the local Code of
Practice should be consulted.
4.2 Zones, gas groups and T rating
The BA488C EC-Type Examination certificate
ITS02ATEX2036X confirms that it complies with
the requirements for Group II Category 1 G
Ex ia IIC T5 Ga (Tamb –40 to 60oC) apparatus.
When connected to a suitable system the BA488C
may be installed in:
Zone 0 explosive gas air mixture
continuously present.
(Special conditions apply
see below)
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
At an ambient temperature between –40 and
+60°C.
Note: the guaranteed operating temperature range
of the serial text display is –20ºC to +60ºC.
This allows the BA488C to be installed in all Zones
and to be used with most common industrial
gases.
Special conditions for safe use in Zone 0
In the unlikely event of installation in a Zone 0
potentially explosive atmosphere, the BA488C
Serial Text Display shall be installed such that
even in the event of rare incidents, an ignition
source due to impact or friction between the
aluminium enclosure at the rear of the instrument
mounting panel and iron/steel is excluded.
4.3 Power supply
When installed in a hazardous area the BA488C
must be powered from, and communicate via a
certified communications isolator installed in the
safe area. Either a BA201 Communications
Isolator or a MTL5051 Serial Data Comms Isolator
may be used.
Although other certified barriers or galvanic
isolators have output parameters equal to or less
than the BA488C input parameters, because of the
data conversion performed by the BA201 and
MTL5051, currently these are the only suitable
devices.
The maximum permitted cable parameters are
shown in section 5.
4.4 External switches
For applications requiring operator inputs to be
made by large industrial push-buttons, terminals
S1 to S7 allow external switches to be connected
to the text display. When the external push-
buttons are enabled in the configuration menu, the
front panel push-buttons are automatically
disabled.
Terminals S1 to S7 have the following combined
output safety parameters:
Uo = 14.7V dc
Io = 99mA dc
Po = 0.6W
The switches and associated wiring connected to
the terminals must comply with the requirements
for simple apparatus. i.e. they must have IP20
protection and be capable of withstanding a 500V
rms insulation test to earth for one minute. Most
industrial push-buttons satisfy these requirements
7

The total maximum permitted cable parameters for
all the cables connected to terminals S1 to S7 in a
IIC hydrogen gas must be less than:
Co = 0.22µF
Lo = 0.26mH
Although these are the smallest figures specified
by any of the three system certificates using the
MTL5051, they also apply to systems incorporating
the BA201. The parameters are not restrictive
allowing a significant distance between the
switches and the instrument.
4.5 Switch outputs
Each of the two switch outputs 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 switch output will not exceed those specified
for simple apparatus in Clause 5.4 of IEC60079-
11. This allows each of the BA488C switch
outputs to be connected to any intrinsically safe
circuit protected by a certified Zener barrier or
galvanic isolator providing that the output
parameters of each circuit are less than:
Uo = 28V dc
Io = 200mA
Po = 0.85W
The maximum equivalent capacitance and
inductance of each BA488C switch output is:
Ci = 40nF
Li = 20µH
To determine the maximum permissible cable
parameters, Ci and Li must be subtracted from the
maximum cable capacitance and inductance
specified by the system certificate of the circuit
connected to the switch.
4.6 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, location, instrument serial
number and year of manufacture. Non European
certification information may also be included.
8

5. SYSTEM DESIGN FOR HAZARDOUS AREAS
The BA488C serial text display may be powered
and communicate via a BA201 Communications
Isolator or a MTL5051 serial data comms isolator.
Both are certified Associated Apparatus, and their
features are compared in table 1.
BA201 MTL5051
Mounting 35mm DIN rail
Supply 20-35Vdc
Safe area ports RS232
or RS485
2 wire
RS232
or RS422
Port selection Automatic DIL switches
Number of serial
text displays
Up to 4 Up to 2.
Up to 4 with
addition of
MTL5025
galvanic
isolator.
Communication
speed
0.3 to 19.2
k baud
1.2 to 9.6
k baud
Multidrop safe
area port
Yes No
Table 1
5.1 Use with a BA201 Communications Isolator
There are two configurations that may be used for
hazardous area installations. The choice depends
upon how many text displays are required and the
backlight brilliance. Table 2 summarises the
performance of both systems.
Table 2
5.1.1 Cable length
The communications speed, type of cable and to a
lesser extent the permissible intrinsic safety cable
parameters, determine the maximum allowable
cable length between the BA201 communications
isolator and the serial text display(s). Cable
lengths up to 600m have been successfully used at
9.6k baud with an RS232 safe area port.
Using the entity parameters specified by the
BA488C and BA201 ATEX certificates, the
maximum allowable cable parameters in a IIC gas
are:
For a 2-wire system
Number of
Serial Text
Displays
Maximum
permissible
cable
capacitance
Maximum
permissible
cable
inductance
1 0.77µF 4.08mH
2 0.76µF 4.06mH
Table 3
For a 3-wire system
Number of
Serial Text
Displays
Maximum
permissible
cable
capacitance
Maximum
permissible
cable
inductance
1 0.162µF 0.98mH
2 0.152µF 0.96mH
3 0.142µF 0,94mH
4 0.132µF 0.92mH
Table 4
Only the maximum permitted capacitance for a 3-
wire system is likely to limit the cable length.
Assuming a generous maximum cable capacitance
of 300pF/m, this allows up to 440m of cable with
four serial text displays connected to a BA201
isolator. For reference, a typical Belden 8761
single twisted pair with overall shield has a
capacitance of 100pF/m.
9

5.1.2 Two wire system
This is the simplest and probably the most
frequently used system. One or two BA488C
serial text displays are connected to a BA201 in
the safe area via two wires that provide both power
and bi-directional communication.
Fig 2 shows the wiring diagram. With this
configuration data may be transmitted and
received at 0.3, 1.2, 2.4, 4.8, 9.6 or 19.2k baud.
When two BA488C text displays are connected to
a single BA201 via two wires, the brilliance of both
display backlights will be significantly reduced.
Fig 2 Two wire system for RS232 or RS485
5.1.3 Three wire system
The three wire system shown in Fig 3 can power
and address up to four BA488C serial text
displays. If more than two displays are connected,
the backlight brilliance of all the displays will be
significantly reduced.
With this configuration data may be transmitted
and received at 0.3, 1.2, 2.4, 4.8, 9.6 or 19.2k
baud.
Fig 3 Three wire system for RS232 or RS485
10

5.2 Use with a MTL5051 Serial Data Comms
Isolator
There are three configurations that may be used
for hazardous area installations. The choice
depends upon how many text displays are
required, the backlight brilliance and the
communication speed required. Table 5
summarises the performance.
Table 5
5.2.1 Cable length
The dc loop resistance of the cable between the
BA488C and the associated galvanic isolator in the
safe area must not exceed 20. This applies for 2,
3 and 4 wire systems irrespective of the number of
text displays connected to the loop. Most
instrument cables have a loop resistance of
between 50 and 200m per metre, thus limiting
the maximum cable length to between 100 and 400
metres.
The maximum permitted intrinsic safety cable
parameters specified on the system certificates
must also not be exceed. However, in practice
only the capacitive limit in IIC gases is likely to be
restrictive.
Communication speed will also limit the
transmission distance. At 9.6k baud a screened
twisted pair should provide reliable communication
up to 100 metres. If data corruption occurs the
communication speed should be reduced.
5.2.2 Conditioning the MTL5051
The MTL5051 galvanic isolator, may be
conditioned to have an RS232 or RS422 safe area
port. DIL switches accessed from the top of the
isolator perform the conditioning – see Figs 4, 5
and 6 for details.
5.2.3 Two wire system
This is the simplest and probably the most
frequently used system. One or two BA488C
serial text displays are connected to a MTL5051 in
the safe area via two wires that provide both power
and bi-directional communication.
Fig 4 shows the wiring diagram which is defined by
ITS System Certificate Ex02E2037.
With this configuration data may be transmitted
and received at 1.2, 2.4, 4.8 or 9.6k baud. When
two BA488C text displays are connected to a
common galvanic isolator the brilliance of both
display backlights will be significantly reduced.
Fig 4 Two wire system for RS232 or RS422
5.2.4 Three wire system
The three wire system shown in Fig 5 conforms
with system certificate Ex02E2038. It employs an
additional galvanic isolator, the MTL5025 solenoid/
alarm driver, enabling up to four BA488C serial text
displays to be powered and addressed. When
more than two Serial Text Display are connected,
the backlight brilliance of all the displays will be
significantly reduced.
With this configuration data may be transmitted
and received at 1.2, 2.4, 4.8 or 9.6k baud.
11

Fig 5 Three wire system for RS232 or RS422
5.2.5 Four wire system
The four wire system which is defined by ITS
System Certificate Ex02E2039 and shown in Fig 6
allows communication at higher and lower rates
than the other two MTL5051 configurations. It
should be used for applications requiring fast
display updates, or with slow data rates when long
cable runs are required.
Data may be transmitted and received at 0.3, 0.6,
1.2, 2.4, 4.8, 9.6 and 19.2k baud.
Fig 6 Four wire system for RS232 or RS422
12

5.3 Switch outputs
Each switch output is a galvanically isolated single
pole solid state switch output as shown in Fig 7.
Fig 7 Equivalent circuit of each switch output
The outputs are polarised and current will only flow
in one direction. Terminals A1 and A3 should be
connected to the positive side of the supply.
Ron = 5 + 0.7V
Roff = greater than 1M
Note: Because of the series protection diode,
some test meters may not detect a closed alarm
output
WARNING
These switch outputs should not be used
for critical safety applications such as an
emergency shut down system.
When the BA488C power supply is turned off or
disconnected, both BA488C switch outputs will
open irrespective of how they have been
programmed.
13

6. INSTALLATION
6.1 Location
The BA488C is housed in a robust aluminium
enclosure with a toughened glass window mounted
in a Noryl bezel. The front of the instrument
provides IP66 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 8 shows the overall dimensions of the BA488C
and the panel cutout. To achieve an IP66 seal
between the instrument enclosure and the panel,
the smaller cutout must be used and the
instrument secured with four panel mounting clips.
The BA488C liquid crystal display has maximum
contrast when viewed from directly ahead and
slightly below the centre line of the instrument.
Fig 8 BA488C dimensions
6.2 Installation Procedure
a. Insert the BA488C into the instrument panel
cut-out from the front of the panel.
b. Fix panel mounting clips to opposite sides of
the instrument and tighten. Recommended
tightening torque is 22cNm (1.95lbf in). Do
not over tighten. Four clips are required to
achieve an IP66 seal between the
instrument enclosure and the panel.
c. Connect the panel wiring to the rear
terminal block(s) as shown in Fig 9. To
simplify installation, the terminals are
removable so that panel wiring can be
completed before the instrument is
installed.
Fig 9 Installation and terminal connections
14

6.3 EMC
The BA488C complies with the requirements of the
European EMC Directive 2004/108/EEC. For
specified immunity all wiring should be in screened
twisted pairs.
To prevent circulating currents, cable screens
should only be earthed at one point in the safe
area.
15

7. CONFIGURATION
Before the BA488C can be commissioned it must
be configured to be compatible with the host’s
communications format and have the required
functions enabled.
The BA488C is configured via four of the front
panel push-buttons. All the configuration functions
are contained in an easy to use menu shown in
Fig 10. Where necessary the sub-menus contain
on-screen prompts to guide the user through each
adjustment.
When navigating through the configuration menu,
the push-button(s) should be held until the required
screen is displayed.
7.1 Default configuration
Unless otherwise requested at time of ordering,
BA488C text displays will be supplied configured
as follows:
Baud rate 9.6k
Data bits 8
Stop bit 1
Parity None
Protocol BEKA
Units Single
Address 0
Operational mode 1
Keypad Internal
Display brightness 100%
Display contrast 50%
Limit backlight On
Quick access menu On
Show Status Text On
Set Last Valid Input 8
Quick access menu code 0000
Configuration menu
access code. 0000
Key mode 0
Screens Text Display
7.2 Accessing the configuration menus
Throughout this manual push-buttons are shown in
italics e.g. P or Up push-button, and legends
displayed by the instrument are shown within
inverted commas e.g. 'Please enter code'.
The configuration menu is accessed by operating
the P and E push-buttons simultaneously. Fig 8
shows the location of these push-buttons. If the
BA488C is not protected by an access code the
main menu will be displayed. If an access code
other than the default code 0000 has already been
entered, the BA488C will request that the access
code be entered.
Using the Up or Down button set the first digit of
the code which will be flashing. Pressing P will
transfer control to the next digit which should be
adjusted in the same way. When all four digits
have been set, pressing the E button will enter the
access code. If the code is correct the main
menu will be displayed, if the code is incorrect
‘Invalid code’ will be displayed.
When entering an access code, timeout will occur
and the instrument will automatically return to the
operating mode ten seconds after the push-buttons
were last operated. In all other menus timeout
occurs after thirty seconds.
When the main menu is displayed the required
sub-menu can be highlighted by scrolling through
the menu using the Up or Down push-button.
Operating the P push-button will display the
highlighted sub-menu from which a further
selection may be made. After a configuration
parameter has been adjusted, pressing the E
button will enter the selection and move the display
up one level.
After configuration has been completed, operating
the E push-button repeatedly will return the
instrument display to the main menu. One more
operation of the E button will then return the
BA488C to the operating mode.
7.3 Summary of configurable functions
This section provides a brief explanation of each
configurable function and should be read in
conjunction with Fig 10.
Scripts
This is only included in the menu whan a Script
has been loaded into the BA488C.
See Serial Text Display – Progamming Guide
for details.
View settings
Displays the instruments main communication
settings. Adjustments can not be made from
this sub-menu.
Baud rate
Data rate may be set to seven speeds between
0.3 and 19.2k baud. Allowable rates depend
upon the system in which the BA488C is used.
Data bits
7 or 8 data bits may be selected. 8 bit data is
required in BEKA mode for graphics, for error
checked modes and for Modbus.
Stop bits
1 or 2 stop bits may be selected.
16

Parity
An even, odd or no parity bit may be selected.
Protocol
BEKA, Legacy or Modbus protocol may be
selected. The Legacy protocol is compatible
with the MTL644.
Units
Selects single or multiple BA488C displays
connected to a single BA201 or MTL5051.
Address
Each text display must be allocated a unique
address in following range:
Modbus protocol 1 – 247
BEKA protocol 0 – 247 Zero reserved for
Legacy protocol 0 –15 single unit applications.
Operational mode
Five levels of communications security may be
selected, ranging from immediate execution of
a command with no acknowledgement, to a
requirement for a 16 bit cyclic redundancy
check. See the Serial Text Display -
Programming Guide for a detailed explanation.
This function is not available when Legacy
protocol is selected.
Key mode
Key press data can be returned in three ways.
See Response Format Section in the Serial
Text Display - Programming Guide. Not
applicable in the legacy mode.
Keypad
This function allows the instrument front panel
push-buttons or external push-buttons to be
used for operator inputs. Whichever are
selected, the instrument front panel push-
buttons are used for configuration.
This function is not available when Legacy
protocol is selected.
Screens
One of eleven standard screens or a custom
screen may be selected
Not applicable with Legacy protocol.
Display settings
Allows the backlight brightness and contrast of
the BA488C display to be adjusted.
Limit backlight
When ‘On’ is selected the maximum backlight
brightness will be automatically set depending
upon whether a ‘Single Unit’ or ‘Multiple Unit’
has been selected in the configuration menu.
When ‘Off’ is selected the automatic brilliance
limit is overridden for special applications. e.g.
Two text displays on a three wire system.
Quick access menu
This function enables the quick access menu
described in section 7.4. When ‘On’ is
selected an operator can adjust the screen
brilliance and contrast without having access to
other conditioning parameters.
Access code for the Quick Access Menu
‘Access Code’ in the display menu defines the
four digit alphanumeric code that must be
entered to gain access to the instrument’s quick
access menu. Alpha characters are case
sensitive. Default code 0000 allows direct
access without a code.
Status Text
The two single variable screens include a
message ‘Status: Good or Status: Bad’, the
Status Text function allows this message to be
inhibited.
Last Valid Input
This function allows the number of process
variables to be entered so that when scrolling
the display unused screens are not shown.
Access code for the Configuration Menu
‘Code’ in the main menu defines the four digit
alphanumeric code that must be entered to gain
access to the instrument configuration menus.
Apha characters are case sensitive. Default
code 0000 allows direct access without a code.
Unit information
Displays the instrument model number and the
firmware version.
Configuration defaults
This function allows the configuration default
defined in section 7.1 to be globally set.
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7.4 Quick Access Menu
The quick access menu allows an operator to
adjust the backlight brilliance and the display
contrast without having access to the other
configuration parameters.
The quick access menu is accessed by operating
the P and Up push-buttons simultaneously. Fig 8
shows the location of these push-buttons. If the
quick access menu is not protected by an access
code the brilliance and contrast controls will be
displayed immediately. If an access code other
than the default code 0000 has already been
entered, the BA488C will request that the access
code be entered. Section 7.2 explains how an
access code should be entered.
The backlight brilliance is adjusted using the Up
and Down push-buttons. Operating the P push-
button will transfer control to the display contrast
adjustment. When both are set as required
operating the E button will store both settings and
return the instrument to the operating mode.
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8. MAINTENANCE
8.1 Fault finding during commissioning
If a BA488C fails to function during commissioning
the following procedure should be followed:
Symptom Cause Check:
No Display No Power
Incorrect wiring
That there is 10
to 14 volts
between terminal
1 and 2 of the
seven way
connector.
Terminal 1
should be
positive.
No
Communication
Communications
parameters
incorrectly set
Baud rate, data
bits, stop bits and
parity settings
match those of
the host.
If MTL5051 used
Position of
configuration
switches on
MTL5051 Serial
Data Comms
Isolator.
If BA201 is used.
Port on BA201
Communications
Isolator.
Incorrect
Protocol
Protocol settings
in “Comms”
Menu
Incorrect wiring Wiring is as
shown in diagram
for chosen
configuration
Address incorrect
in Multidrop
Mode
Address setting
in “Comms”
menu
Poor
Communication
Too many
BA488C displays
on the line.
Lines too long
Communication
speed too fast.
Configuration
settings.
Installation
guidelines
Dark Display Contrast too high Contrast level in
“Display Settings”
menu
No Backlight
or
Backlight dim
Backlight off or
set low
or
Multidrop mode
in use
Brightness level
in “Display
Settings” menu
Units setting in
“Comms” menu
Cannot enter
configuration
menu
Push-buttons not
held for long
enough (up to 2
seconds
required)
Menu inhibited
Send
“Configuration
Enable”
command
(BEKA protocol)
Restart unit
(Legacy protocol)
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 BA488C fails after it has been functioning
correctly, the table shown in section 8.1 may help
to identify the cause of the failure.
If this procedure does not reveal the cause of the
fault, please contact BEKA or our local agent.
8.3 Servicing
We recommend that faulty BA488C serial text
displays are returned to BEKA associates or to our
local agent for repair.
8.4 Routine maintenance
The mechanical and electrical condition of the
instrument should be regularly checked. Initially
annual inspections are recommended, but the
inspection frequency should be adjusted to suit the
environmental conditions.
8.5 Guarantee
Instruments 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.
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