Issue: 131st March 2012

BA488CIntrinsically safePanel mounting

Serial text displayIssue 13

21. Description1.1 Documentation1.2 Version 3 firmware1.3 Version 3.4 firmware

2. Operation

3. Applications3.1 Legacy protocol3.2 Modbus protocol3.3 BEKA protocol

4. Intrinsic Safety Certification4.1 ATEX certificate4.2 Zones, gas groups and T rating4.3 Power supply4.4 External switches4.5 Switch outputs4.6 Certification label information

5. System Design for Hazardous Area5.1 Use with a BA201 Communications

Isolator.5.1.1 Cable length5.1.2 Two wire system5.1.3 Three wire system

5.2 Use with MTL5051 Serial Data CommsIsolator.5.2.1 Cable length5.2.2 Conditioning MTL50515.2.3 Two wire system5.2.4 Three wire system5.2.5 Four wire system

5.3 Switch outputs

6. Installation6.1 Location6.2 Installation procedure6.3 EMC

7. Configuration7.1 Default configuration7.2 Accessing the configuration menus7.3 Summary of configurable functions7.4 Quick access menu

8. Maintenance8.1 Fault finding during commissioning8.2 Fault finding after commissioning8.3 Servicing8.4 Routine maintenance8.5 Guarantee8.6 Customer comments

9. Accessories9.1 Tag number9.2 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

CONTENTS

The BA488C is CE marked to show compliance with theEuropean Explosive Atmospheres Directive 94/9/EC

and the European EMC Directive 2004/108/EC

31. DESCRIPTIONThe BA488C is an intrinsically safe instrument thatcan display text and simple graphics in ahazardous area. Incorporating six operator push-buttons, two solid state outputs and a backlit 120 x64 pixel graphical display, it is a versatile operatorinterface for simple machine or process controlapplications.

Housed in a robust 72 x 144 panel mounting DINenclosure, the BA488C text display has an IP66front panel and is supplied with a gasket to sealthe joint between the instrument and the panel.

The BA488C text display has been issued with anEC-Type Examination Certificate by Notified BodyIntertek Testing and Certification Ltd for gasatmospheres which has been used to confirmcompliance with the European PotentiallyExplosive Atmospheres Directive 94/9/EC.

For use in the USA and Canada the instrumenthas intrinsic safety and nonincendive FM and cFMApproval see Appendix 2.

For international applications the BA488C also hasIECEx certification see Appendix 3.

1.1 DocumentationThis instruction manual describes system design,conditioning and installation of the BA488C serialtext display. To quickly install and commission aBA488C for a basic application, please readAppendix 1 Getting Started Quickly.

For detailed programming information separateguides describe the Modbus RTU and BEKAprotocols. These are available from our salesdepartment or may be downloaded fromwww.beka.co.uk.

Serial Text DisplayModbus Interface GuideDescription of parametersUse with standard screens

Serial Text DisplayProgramming GuideBEKA protocolCommand summary & referenceScriptingPattern matchingAdvanced features

1.2 Version 3 FirmwareThis manual describes the enhanced featuresavailable in text displays employing version 3.0firmware which was released in August 2005.Namely:

Modbus protocolCyclic data and mapped variablesNine tandard screensScriptingPattern matchingSpeed increaseFont 5 soft font storage

The instruments firmware version can beestablished using the Unit Info function in themain configuration menu - see section 7.3 of thismanual. Text displays employing Version 3.0firmware are backwards compatible with all earlierversions.

1.3 Version 3.4 FirmwareThis manual describes the additional featuresavailable in text displays employing version 3.4firmware which was released in October 2009.Namely:

Two eight variable standard screens added.

Integer variables added to the Modbus registermap to complement the original float values.

New function allows the number of processvariables to be entered, so that when scrollingthe display unused screens are not shown.

Enhancements to to the Scripting facility.

The instruments firmware version can beestablished using the Unit Info function in themain configuration menu - see section 7.3 of thismanual. Text displays employing Version 3.4firmware are backwards compatible with all earlierversions.

42. OPERATIONFig 1 shows a simplified block diagram of aBA488C serial text display. The instrument isconnected to a serial data galvanic isolator in thesafe area via two, three or four wires that carryboth power and bi-directional communication.The switch outputs may be controlled and theoperator switches interrogated from the safe areavia the serial communication link.

Fig 1 Simplified block diagram of BA488C

Two alternative certified galvanic isolators may beused to power and communicate with the display.The BA201 communications isolator has an RS232or two wire RS485 safe area port and can supportup to to four BA488C displays with serial numbersabove 42518/ i.e. manufactured after Sept.2007. The MTL5051 serial data comms isolatorhas an RS232 or RS422 safe area port and cansupport one or two displays, or up to four with theaddition of an MTL5025 solenoid driver. Seesection 5 for details.

3. APPLICATIONSThe BA488C has been designed for easyintegration with most serial data sources andtherefore contains a wealth of features. Althoughat first sight the complexity may seem daunting,the support documentation is application related sothat only relevant sections need to be read. Ifadditional help is needed BEKA engineers arealways willing to assist with system design,programming and screen development.

The BA488C may be used with three alternativeprotocols; legacy, BEKA or Modbus RTU. Thepattern matching function also enables proprietaryASCII serial data, such as that from a weighingsystem, to be decoded and displayed. Thisadvanced feature is described in the Serial TextDisplay Programming Guide.

Legacy protocolThe legacy protocol contained in the BA488Callows the instrument to replace an MTL644 IS textdisplay. All the functions of an MTL644 arereplicated, but with the advantage of a backlitdisplay and ATEX certification.

Legacy protocol only allows three externalswitches S1, S2 & S3, not the front panel push-buttons, to be used for operator inputs. Similarly,the MTL644 only has one output control, so thetwo switch outputs operate in parallel.

When using the legacy protocol, the configurationmenus are only operational between power beingapplied to the BA488C and the first message beingreceived.

3.2 Modbus RTU protocolThe BA488C supports Modbus RTU protocol inslave mode. Up to eight process variables,together with their units of measurement and tagdescription may be displayed on one of the elevenstandard screen formats shown below. Theseillustrate typical units of measurement and taginformation, but any may be entered. This allowsone, two, four or eight process variables to beshown on a common screen without the need forany programming, apart from setting the BA488Caddress and writing each Modbus variable in therequired Modbus register address map.

If more process variables than can be shown onthe selected standard screen are to be displayed,the operator can select which process variablesare shown by operating the Up or Down push-buttons. This selection can also be made by thesystem host.

5One 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 sixfront panel push-buttons to be interrogated so theymay be used for operator controls. If largerindustrial size push-buttons are required, thesemay be connected to the BA488C terminals.When external switches are used the instrumentfront panel switches are disabled.

The two single pole solid state outputs may becontrolled via Modbus allowing certified hazardousarea loads such as sounders, beacons and valvesto be turned on and off.

For more demanding applications BEKA protocolmay be used to construct custom display screensfor use in a Modbus system.

Modbus protocol is described in the Serial TextDisplay Modbus Guide, which is available fromthe BEKA sales office and from the BEKA website.

63.3 BEKA protocolBEKA protocol enables text to be written anywhereon the screen in five different font sizes, togetherwith lines, boxes and bargraphs. Alternatively oneof the nine standard display screens described insection 3.2 may be used.

Simple bit map graphics may also be downloadedto the display and all characters can be reversedor flashed. Information may also be written to ahidden screen that may be displayed whenrequired.

This protocol enables each of the six front panelpush-buttons to be interrogated so they may beused for operator controls. By displaying theswitch function on the screen adjacent to thebutton, soft switches can be created. If largerindustrial size push-buttons are required, thesemay be connected to the BA488C terminals.When external switches are used the front panelswitches are disabled.

Two single pole solid state outputs may be used toswitch certified hazardous area loads such assounders, beacons and valves.

BEKA protocol is described in the Serial TextDisplay Programming Guide which is availablefrom the BEKA sales office and from the BEKAweb site.

74. INTRINSIC SAFETY CERTIFICATION

4.1 ATEX certificateThe BA488C has been issued with EC-TypeExamination Certificate ITS02ATEX2036X byNotified Body Intertek Testing & Certification Ltd(ITS). This has been used to confirm compliancewith the European ATEX Directive 94/9/EC forGroup II, Category 1, gas atmospheres,Ex ia IIC T5 Ga. The instrument bears theCommunity Mark and, subject to local codes ofpractice, may be installed in any of the EuropeanEconomic Area (EEA) member countries. ATEXcertificates are also acceptable for installations inSwitzerland.

This manual describes installations in explosivegas atmospheres which conform withIEC 60079: Part 14 Electrical installation design,selection and erection. When designing systemsfor installation outside the UK, the local Code ofPractice should be consulted.

4.2 Zones, gas groups and T ratingThe BA488C EC-Type Examination certificateITS02ATEX2036X confirms that it complies withthe requirements for Group II Category 1 GEx ia IIC T5 Ga (Tamb 40 to 60oC) apparatus.When connected to a suitable system the BA488Cmay be installed in:

Zone 0 explosive gas air mixturecontinuously present.(Special conditions applysee below)

Zone 1 explosive gas air mixturelikely to occur in normaloperation.

Zone 2 explosive gas air mixture notlikely to occur, and if it does willonly exist for a short time.

Be used with gases in groups:Group A propaneGroup B ethyleneGroup C hydrogen

Having a temperature classification of:T1 450CT2 300CT3 200CT4 135CT5 100C

At an ambient temperature between 40 and+60C.Note: the guaranteed operating temperature rangeof the serial text display is 20C to +60C.

This allows the BA488C to be installed in all Zonesand to be used with most common industrialgases.

Special conditions for safe use in Zone 0In the unlikely event of installation in a Zone 0potentially explosive atmosphere, the BA488CSerial Text Display shall be installed such thateven in the event of rare incidents, an ignitionsource due to impact or friction between thealuminium enclosure at the rear of the instrumentmounting panel and iron/steel is excluded.

4.3 Power supplyWhen installed in a hazardous area the BA488Cmust be powered from, and communicate via acertified communications isolator installed in thesafe area. Either a BA201 CommunicationsIsolator or a MTL5051 Serial Data Comms Isolatormay be used.

Although other certified barriers or galvanicisolators have output parameters equal to or lessthan the BA488C input parameters, because of thedata conversion performed by the BA201 andMTL5051, currently these are the only suitabledevices.

The maximum permitted cable parameters areshown in section 5.

4.4 External switchesFor applications requiring operator inputs to bemade by large industrial push-buttons, terminalsS1 to S7 allow external switches to be connectedto the text display. When the external push-buttons are enabled in the configuration menu, thefront panel push-buttons are automaticallydisabled.

Terminals S1 to S7 have the following combinedoutput safety parameters:

Uo = 14.7V dcIo = 99mA dcPo = 0.6W

The switches and associated wiring connected tothe terminals must comply with the requirementsfor simple apparatus. i.e. they must have IP20protection and be capable of withstanding a 500Vrms insulation test to earth for one minute. Mostindustrial push-buttons satisfy these requirements

8The total maximum permitted cable parameters forall the cables connected to terminals S1 to S7 in aIIC hydrogen gas must be less than:

Co = 0.22FLo = 0.26mH

Although these are the smallest figures specifiedby any of the three system certificates using theMTL5051, they also apply to systems incorporatingthe BA201. The parameters are not restrictiveallowing a significant distance between theswitches and the instrument.

4.5 Switch outputsEach of the two switch outputs is a separategalvanically isolated solid state switch. The EC-Type Examination Certificate specifies that underfault conditions the voltage, current and power ateach switch output will not exceed those specifiedfor simple apparatus in Clause 5.4 of IEC60079-11. This allows each of the BA488C switchoutputs to be connected to any intrinsically safecircuit protected by a certified Zener barrier orgalvanic isolator providing that the outputparameters of each circuit are less than:

Uo = 28V dcIo = 200mAPo = 0.85W

The maximum equivalent capacitance andinductance of each BA488C switch output is:

Ci = 40nFLi = 20H

To determine the maximum permissible cableparameters, Ci and Li must be subtracted from themaximum cable capacitance and inductancespecified by the system certificate of the circuitconnected to the switch.

4.6 Certification Label InformationThe certification label is fitted in a recess on thetop outer surface of the enclosure. It shows theATEX certification information plus BEKAassociates name, location, instrument serialnumber and year of manufacture. Non Europeancertification information may also be included.

95. SYSTEM DESIGN FOR HAZARDOUS AREASThe BA488C serial text display may be poweredand communicate via a BA201 CommunicationsIsolator or a MTL5051 serial data comms isolator.Both are certified Associated Apparatus, and theirfeatures are compared in table 1.

BA201 MTL5051

Mounting 35mm DIN railSupply 20-35VdcSafe area ports RS232

or RS485 2 wire

RS232 or RS422

Port selection Automatic DIL switchesNumber of serialtext displays

Up to 4 Up to 2.Up to 4 withaddition ofMTL5025galvanicisolator.

Communicationspeed

0.3 to 19.2k baud

1.2 to 9.6k baud

Multidrop safearea port

Yes No

Table 1

5.1 Use with a BA201 Communications IsolatorThere are two configurations that may be used forhazardous area installations. The choice dependsupon how many text displays are required and thebacklight brilliance. Table 2 summarises theperformance of both systems.

Table 2

5.1.1 Cable lengthThe communications speed, type of cable and to alesser extent the permissible intrinsic safety cableparameters, determine the maximum allowablecable length between the BA201 communicationsisolator and the serial text display(s). Cablelengths up to 600m have been successfully usedat 9.6k baud with an RS232 safe area port.

Using the entity parameters specified by theBA488C and BA201 ATEX certificates, themaximum allowable cable parameters in a IIC gasare:

For a 2-wire system

Number ofSerial TextDisplays

Maximumpermissible

cablecapacitance

Maximumpermissible

cableinductance

1 0.77F 4.08mH2 0.76F 4.06mH

Table 3

For a 3-wire system

Number ofSerial TextDisplays

Maximumpermissible

cablecapacitance

Maximumpermissible

cableinductance

1 0.162F 0.98mH2 0.152F 0.96mH3 0.142F 0,94mH4 0.132F 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 capacitanceof 300pF/m, this allows up to 440m of cable withfour serial text displays connected to a BA201isolator. For reference, a typical Belden 8761single twisted pair with overall shield has acapacitance of 100pF/m.

10

5.1.2 Two wire systemThis is the simplest and probably the mostfrequently used system. One or two BA488Cserial text displays are connected to a BA201 inthe safe area via two wires that provide both powerand bi-directional communication.

Fig 2 shows the wiring diagram. With thisconfiguration data may be transmitted andreceived at 0.3, 1.2, 2.4, 4.8, 9.6 or 19.2k baud.When two BA488C text displays are connected toa single BA201 via two wires, the brilliance of bothdisplay backlights will be significantly reduced.

Fig 2 Two wire system for RS232 or RS485

5.1.3 Three wire systemThe three wire system shown in Fig 3 can powerand address up to four BA488C serial textdisplays. If more than two displays are connected,the backlight brilliance of all the displays will besignificantly reduced.With this configuration data may be transmittedand received at 0.3, 1.2, 2.4, 4.8, 9.6 or 19.2kbaud.

Fig 3 Three wire system for RS232 or RS485

11

5.2 Use with a MTL5051 Serial Data CommsIsolator

There are three configurations that may be usedfor hazardous area installations. The choicedepends upon how many text displays arerequired, the backlight brilliance and thecommunication speed required. Table 5summarises the performance.

Table 5

5.2.1 Cable lengthThe dc loop resistance of the cable between theBA488C and the associated galvanic isolator in thesafe area must not exceed 20. This applies for 2,3 and 4 wire systems irrespective of the number oftext displays connected to the loop. Mostinstrument cables have a loop resistance ofbetween 50 and 200m per metre, thus limitingthe maximum cable length to between 100 and400 metres.

The maximum permitted intrinsic safety cableparameters specified on the system certificatesmust also not be exceed. However, in practiceonly the capacitive limit in IIC gases is likely to berestrictive.

Communication speed will also limit thetransmission distance. At 9.6k baud a screenedtwisted pair should provide reliable communicationup to 100 metres. If data corruption occurs thecommunication speed should be reduced.

5.2.2 Conditioning the MTL5051The MTL5051 galvanic isolator, may beconditioned to have an RS232 or RS422 safe areaport. DIL switches accessed from the top of theisolator perform the conditioning see Figs 4, 5and 6 for details.

5.2.3 Two wire systemThis is the simplest and probably the mostfrequently used system. One or two BA488Cserial text displays are connected to a MTL5051 inthe safe area via two wires that provide both powerand bi-directional communication.

Fig 4 shows the wiring diagram which is defined byITS System Certificate Ex02E2037.With this configuration data may be transmittedand received at 1.2, 2.4, 4.8 or 9.6k baud. Whentwo BA488C text displays are connected to acommon galvanic isolator the brilliance of bothdisplay backlights will be significantly reduced.

Fig 4 Two wire system for RS232 or RS422

5.2.4 Three wire systemThe three wire system shown in Fig 5 conformswith system certificate Ex02E2038. It employs anadditional galvanic isolator, the MTL5025solenoid/alarm driver, enabling up to four BA488Cserial text displays to be powered and addressed.When more than two Serial Text Display areconnected, the backlight brilliance of all thedisplays will be significantly reduced.With this configuration data may be transmittedand received at 1.2, 2.4, 4.8 or 9.6k baud.

12

Fig 5 Three wire system for RS232 or RS422

5.2.5 Four wire systemThe four wire system which is defined by ITSSystem Certificate Ex02E2039 and shown in Fig 6allows communication at higher and lower ratesthan the other two MTL5051 configurations. Itshould be used for applications requiring fastdisplay updates, or with slow data rates when longcable 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

13

5.3 Switch outputsEach switch output is a galvanically isolated singlepole 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 flowin one direction. Terminals A1 and A3 should beconnected to the positive side of the supply.

Ron = 5 + 0.7VRoff = greater than 1M

Note: Because of the series protection diode,some test meters may not detect a closed alarmoutput

WARNINGThese switch outputs should not be usedfor critical safety applications such as anemergency shut down system.

When the BA488C power supply is turned off ordisconnected, both BA488C switch outputs willopen irrespective of how they have beenprogrammed.

14

6. INSTALLATION

6.1 LocationThe BA488C is housed in a robust aluminiumenclosure with a toughened glass window mountedin a Noryl bezel. The front of the instrumentprovides IP66 protection and a gasket seals thejoint between the instrument enclosure and thepanel. The instrument may be installed in anypanel providing the environmental limits shown inthe specification are not exceeded.

Fig 8 shows the overall dimensions of the BA488Cand the panel cutout. To achieve an IP66 sealbetween the instrument enclosure and the panel,the smaller cutout must be used and theinstrument secured with four panel mounting clips.

The BA488C liquid crystal display has maximumcontrast when viewed from directly ahead andslightly below the centre line of the instrument.

Fig 8 BA488C dimensions

6.2 Installation Procedure

a. Insert the BA488C into the instrument panelcut-out from the front of the panel.

b. Fix panel mounting clips to opposite sides ofthe instrument and tighten until theinstrument is secure as shown in Fig 9.Four clips are required to achieve an IP66seal between the instrument enclosure andthe panel.

c. Connect the panel wiring to the rearterminal block(s) as shown in Fig 9. Tosimplify installation, the terminals areremovable so that panel wiring can becompleted before the instrument isinstalled.

Fig 9 Installation and terminal connections

15

6.3 EMCThe BA488C complies with the requirements of theEuropean EMC Directive 2004/108/EEC. Forspecified immunity all wiring should be in screenedtwisted pairs.

To prevent circulating currents, cable screensshould only be earthed at one point in the safearea.

16

7. CONFIGURATIONBefore the BA488C can be commissioned it mustbe configured to be compatible with the hostscommunications format and have the requiredfunctions enabled.

The BA488C is configured via four of the frontpanel push-buttons. All the configuration functionsare contained in an easy to use menu shown inFig 10. Where necessary the sub-menus containon-screen prompts to guide the user through eachadjustment.

When navigating through the configuration menu,the push-button(s) should be held until the requiredscreen is displayed.

7.1 Default configurationUnless otherwise requested at time of ordering,BA488C text displays will be supplied configuredas follows:

Baud rate 9.6kData bits 8Stop bit 1Parity NoneProtocol BEKAUnits SingleAddress 0Operational mode 1Keypad InternalDisplay brightness 100%Display contrast 50%Limit backlight OnQuick access menu OnShow Status Text OnSet Last Valid Input 8Quick access menu code 0000Configuration menu access code. 0000Key mode 0Screens Text Display

7.2 Accessing the configuration menusThroughout this manual push-buttons are shown initalics e.g. P or Up push-button, and legendsdisplayed by the instrument are shown withininverted commas e.g. 'Please enter code'.

The configuration menu is accessed by operatingthe P and E push-buttons simultaneously. Fig 8shows the location of these push-buttons. If theBA488C is not protected by an access code themain menu will be displayed. If an access codeother than the default code 0000 has already beenentered, the BA488C will request that the accesscode be entered.

Using the Up or Down button set the first digit ofthe code which will be flashing. Pressing P will

transfer control to the next digit which should beadjusted in the same way. When all four digitshave been set, pressing the E button will enter theaccess code. If the code is correct the mainmenu will be displayed, if the code is incorrectInvalid code will be displayed.

When entering an access code, timeout will occurand the instrument will automatically return to theoperating mode ten seconds after the push-buttonswere last operated. In all other menus timeoutoccurs after thirty seconds.

When the main menu is displayed the requiredsub-menu can be highlighted by scrolling throughthe menu using the Up or Down push-button.Operating the P push-button will display thehighlighted sub-menu from which a furtherselection may be made. After a configurationparameter has been adjusted, pressing the Ebutton will enter the selection and move the displayup one level.

After configuration has been completed, operatingthe E push-button repeatedly will return theinstrument display to the main menu. One moreoperation of the E button will then return theBA488C to the operating mode.

7.3 Summary of configurable functionsThis section provides a brief explanation of eachconfigurable function and should be read inconjunction with Fig 10.

ScriptsThis is only included in the menu whan a Scripthas been loaded into the BA488C.See Serial Text Display Progamming Guidefor details.

View settingsDisplays the instruments main communicationsettings. Adjustments can not be made fromthis sub-menu.

Baud rateData rate may be set to seven speeds between0.3 and 19.2k baud. Allowable rates dependupon the system in which the BA488C is used.

Data bits7 or 8 data bits may be selected. 8 bit data isrequired in BEKA mode for graphics, for errorchecked modes and for Modbus.

Stop bits1 or 2 stop bits may be selected.

17

ParityAn even, odd or no parity bit may be selected.

ProtocolBEKA, Legacy or Modbus protocol may beselected. The Legacy protocol is compatiblewith the MTL644.

UnitsSelects single or multiple BA488C displaysconnected to a single BA201 or MTL5051.

AddressEach text display must be allocated a uniqueaddress in following range:

Modbus protocol 1 247BEKA protocol 0 247 Zero reserved forLegacy protocol 0 15 single unit applications.

Operational modeFive levels of communications security may beselected, ranging from immediate execution ofa command with no acknowledgement, to arequirement for a 16 bit cyclic redundancycheck. See the Serial Text Display -Programming Guide for a detailed explanation.This function is not available when Legacyprotocol is selected.

Key modeKey press data can be returned in three ways.See Response Format Section in the SerialText Display - Programming Guide. Notapplicable in the legacy mode.

KeypadThis function allows the instrument front panelpush-buttons or external push-buttons to beused for operator inputs. Whichever areselected, the instrument front panel push-buttons are used for configuration.This function is not available when Legacyprotocol is selected.

ScreensOne of eleven standard screens or a customscreen may be selectedNot applicable with Legacy protocol.

Display settingsAllows the backlight brightness and contrast ofthe BA488C display to be adjusted.

Limit backlightWhen On is selected the maximum backlightbrightness will be automatically set dependingupon whether a Single Unit or Multiple Unithas been selected in the configuration menu.When Off is selected the automatic brilliancelimit is overridden for special applications. e.g.Two text displays on a three wire system.

Quick access menuThis function enables the quick access menudescribed in section 7.4. When On isselected an operator can adjust the screenbrilliance and contrast without having access toother conditioning parameters.

Access code for the Quick Access MenuAccess Code in the display menu defines thefour digit alphanumeric code that must beentered to gain access to the instruments quickaccess menu. Alpha characters are casesensitive. Default code 0000 allows directaccess without a code.

Status TextThe two single variable screens include amessage Status: Good or Status: Bad, theStatus Text function allows this message to beinhibited.

Last Valid InputThis function allows the number of processvariables to be entered so that when scrollingthe display unused screens are not shown.

Access code for the Configuration MenuCode in the main menu defines the four digitalphanumeric code that must be entered to gainaccess to the instrument configuration menus.Apha characters are case sensitive. Defaultcode 0000 allows direct access without a code.

Unit informationDisplays the instrument model number and thefirmware version.

Configuration defaultsThis function allows the configuration defaultdefined in section 7.1 to be globally set.

18

7.4 Quick Access MenuThe quick access menu allows an operator toadjust the backlight brilliance and the displaycontrast without having access to the otherconfiguration parameters.

The quick access menu is accessed by operatingthe P and Up push-buttons simultaneously. Fig 8shows the location of these push-buttons. If thequick access menu is not protected by an accesscode the brilliance and contrast controls will bedisplayed immediately. If an access code otherthan the default code 0000 has already beenentered, the BA488C will request that the accesscode be entered. Section 7.2 explains how anaccess code should be entered.

The backlight brilliance is adjusted using the Upand Down push-buttons. Operating the P push-button will transfer control to the display contrastadjustment. When both are set as requiredoperating the E button will store both settings andreturn the instrument to the operating mode.

19

20

8. MAINTENANCE

8.1 Fault finding during commissioningIf a BA488C fails to function during commissioningthe following procedure should be followed:

Symptom Cause Check:No Display No Power

Incorrect wiring

That there is 10to 14 volts

between terminal1 and 2 of the

seven wayconnector.Terminal 1should bepositive.

Communicationsparameters

incorrectly set

Baud rate, databits, stop bits and

parity settingsmatch those of

the host.

If MTL5051 usedPosition of

configurationswitches on

MTL5051 SerialData Comms

Isolator.

If BA201 is used.Port on BA201

CommunicationsIsolator.

IncorrectProtocol

Protocol settingsin Comms

MenuIncorrect wiring Wiring is as

shown indiagram for

chosenconfiguration

NoCommunication

Address incorrectin Multidrop

Mode

Address settingin Comms

menu

PoorCommunication

Too manyBA488C displays

on the line.

Lines too long

Communicationspeed too fast.

Configurationsettings.

Installationguidelines

Dark Display Contrast too high Contrast level inDisplay

Settings menu

No Backlightor

Backlight dim

Backlight off orset low

orMultidrop mode

in use

Brightness levelin Display

Settings menu

Units setting inComms menu

Cannot enterconfiguration

menu

Push-buttons notheld for long

enough (up to 2secondsrequired)

Menu inhibited

SendConfiguration

Enablecommand

(BEKA protocol)

Restart unit(Legacy protocol)

8.2 Fault finding after commissioning

ENSURE PLANT SAFETY BEFORESTARTING MAINTENANCE

Live maintenance is permitted onintrinsically safe equipment installed in ahazardous area, but only certified testequipment should be used unless a gasclearance certificate is available.

If a BA488C fails after it has been functioningcorrectly, the table shown in section 8.1 may helpto identify the cause of the failure.

If this procedure does not reveal the cause of thefault, please contact BEKA or our local agent.

8.3 ServicingWe recommend that faulty BA488C serial textdisplays are returned to BEKA associates or to ourlocal agent for repair.

8.4 Routine maintenanceThe mechanical and electrical condition of theinstrument should be regularly checked. Initiallyannual inspections are recommended, but theinspection frequency should be adjusted to suit theenvironmental conditions.

8.5 GuaranteeInstruments which fail within the guarantee periodshould be returned to BEKA associates or our localagent. It is helpful if a brief description of the faultsymptoms is provided.

8.6 Customer commentsBEKA associates is always pleased to receivecomments from customers about our products andservices. All communications are acknowledgedand whenever possible, suggestions areimplemented.

21

9. ACCESSORIES

9.1 Tag numberThe BA488C can be supplied with a thermallyprinted tag number on the rear panel. This tagnumber is not visible from the front of theinstrument after installation.

9.2 Serial Text Display - Programming GuideA detailed guide to programming the BA488Cserial text display using BEKA protocol may berequested from the BEKA sales office ordownloaded from the BEKA website atwww.beka.co.uk.

9.3 Serial Text Display Modbus Interface GuideThis guide explains how to use the BA488C serialtext display as a slave in Modbus RTU systems. Itmay be requested from the BEKA sales office ordownloaded from the BEKA website atwww.beka.co.uk.

22

10. INDEX

Subject Section

Address 7.3ATEX Directive 4.1, 4.7BA201 Communications Isolator. 2, 4.3, 5.1

Backlight 5.1, 5.2, 7.1BEKA protocol 3.3

CableLength 5.1.1, 5.2.1Parameters 4.4, 4.5, 5.1.1

CertificatesEC-Type Examination 4.1Factory Mutual (FM) Appendix 2Factory Mutual (cFM) Appendix 2IECEx Appendix 3Label 4.6System 4.7

Communication speed 5.Configuration 7.

Access 7.2Default settings 7.1Structure Fig 10Quick access menu 7.4

EMC 6.3External switches 4.4

Factory Mutual (FM) Appendix 2Fault finding

During commissioning 8.1After commissioning 8.2

Galvanic isolators 4.3, 5Gas groups 4.2Getting Started Quickly Appendix 1Guarantee 8.5

Installation 6.2Intrinsic safety 1, 4, 5,

Appendix 2

Legacy protocol 3.1Location 6.1

Subject Section

Maintenance 8.Routine 8.4

Modbus 3.2, 9.3MTL644 display 3.1MTL5051 serial datacomms isolator. 2., 4.3, 5.2MTL5025 galvanic isolator 2., 5.2.4

Nonincendive Approval A2.2Notified Body 4.1

Pattern matching 1.1, 1.2, 3Power supply 4.3

Scripts 1.1, 1.2, 7.3Servicing 8.3Standard screens 3.2Switch outputs 5.3Systems

Two wire 5.1.2, 5.2.3Three wire 5.1.3, 5.2.4Four wire 5.2.5Certificates 4.7

T rating 4.2Terminal numbers Fig 9Timeout 7.2

Zones 4.2

23

APPENDIX 1Getting Started QuicklyThis appendix provides simple step-by-stepinstructions to get a BA488C Serial Text Displayfunctioning quickly.

Communication1. Using a BA201 Communications Isolator

choose a two or three wire system see Figs2 and 3. Connect the safe areacommunications cable to the required port onthe BA201.

or

Using a MTL5051 Serial Data Comms Isolatorchoose a two, three or four wire system - seeFigs 4, 5 & 6.Set the DIP switches on the top of the top of theMTL5051 isolator to provide the required port(RS232 or RS422) and connect the safe areacommunications cable to the correct terminals.

2. Apply power to the galvanic isolator(s).

3. The BA488C will display the model number andsoftware details for a few seconds beforereverting to the BEKA logo.

4. To set the instruments basic communicationsparameters enter the configuration menu bypressing the P and E push-buttonssimultaneously. Fig 10 shows the menustructure and navigation.The P button enters a menu, the Up and Downbuttons select the required sub-menu or settingand the E button enters the selection andmoves the display up one level.

The following menu items must be configuredbefore use:

Parameter SelectBaud Rate Comms. speedData Bits 7 or 8 data bitsStop Bits 1 or 2 stop bitsParity Even, odd or noneProtocol BEKA, Legacy or

Modbus.Units 1 or more displays

per BA201 or MTL5051isolator.

Address Range depends onprotocol: Legacy 1 to 15 BEKA 0 to 247 Modbus 0 to 247

The host and BA488C Serial Text Display shouldnow be able to communicate with each other.

Modbus protocolUsing Modbus and one of the nine standardscreens is the easiest way to display processvariables on a BA488C serial text display.

Select one of the standard screens shown insection 3.2 from the Screens sub-menu.

Modbus register addresses for the instrument areshown in the BEKA Serial Text Display ModbusInterface Guide, which is available from the BEKAsales office or from www.beka.co.uk

BEKA protocolPlease refer to the BEKA Serial Text Display Programming Guide which is available from theBEKA sales office or from www.beka.co.uk

24

APPENDIX 2FM approval for use in USA and cFM Approvalfor use in Canada

A2.0 Factory Mutual ApprovalFor installations in the USA and Canada theBA488C has FM and cFM intrinsically safe andnonincendive approvals, project identification3025514 and 3032633C. Copies of theCertificates of Compliance are available fromBEKA associates and our US agent.

A2.1 Intrinsic safety approvalThe BA488C is approved to the FM Class 3610intrinsic safety standard for use in hazardous(classified) locations. Installations must complywith BEKA associates Control Drawing CI480-07,which is attached to this Appendix, ANSI/ISARP12.06.01 Installation of Intrinsically SafeSystems for Hazardous (Classified) Locations andwith the National Electrical Code ANSI/NFPA70.

Canadian installations must comply with theCanadian Electrical Code C22.2 and the BEKAControl Drawing CI480-07.

The BA488C has a T4 rating at ambienttemperatures up to +60C and may be used withthe following gases:

Intrinsic SafetyDivision 1 or 2

Class I Group A & B Group C Group D

Zone 0, 1 or 2Class 1 Group IIC Group IIB Group IIA

The FM entity parameters are similar to the ATEXparameters. The intrinsically safe circuits shown inthis manual may therefore be used for installationscomplying with the FM Approval.

For use with the BA201 Communications Isolatorthe installation must comply with FM ApprovalsControl Drawings CI201-12 for the BA201Communications Isolator, and with ControlDrawing CI480-07 for the Intrinsically SafeBA484D & BA488C Serial Text Displays. Bothare included in this Appendix.

A2.2 Nonincendive approvalThe BA488C is Class 3611 nonincendive approvedby Factory Mutual allowing it to be installed inDivision 2 hazardous (classified) locations withoutthe need for Zener barriers or galvanic isolators.Installations must comply with the BEKAassociates Control Drawing CI480-08, which isattached to this Appendix, and with the NationalElectrical Code ANSI/NFPA70.

Canadian installations must comply with theCanadian Electrical Code C22.2 and the BEKAControl Drawing CI480-08.

The BA488C has a T4 rating at ambienttemperatures up to +60C and may be used withthe following gases:

NonincendiveDivision 2

Class I Group A & B Group C Group D

Zone 2Class I Group IIC Group IIB Group IIA

25

26

27

28

29

30

31

32

33

34

35

36

37

38

APPENDIX 3IECEx Certification

A3.0 The IECEx Certification SchemeIECEx is a global certification scheme forexplosion protected products which aims toharmonise international certification standards.For additional information about the IECExcertification scheme and to view the BEKAassociate certificates, please visit www.iecex.com

A3.1 IECEx Certificate of ConformityThe BA488C Serial Text Display has been issuedwith an IECEx Certificate of Conformity numberIECEx ITS 07.0021X which specifies the followingcertification code:

Ex ia IIC T5 GaTa = -40C to 60C

When connected to an IECEx certified galvanicisolator, such as the BA201 CommunicationsIsolator, the BA488C may be installed in:

Zone 0 explosive gas air mixturecontinuously present.(Special conditions apply see below)

Zone 1 explosive gas air mixture likelyto occur in normal operation.

Zone 2 explosive gas air mixture notlikely to occur, and if it does willonly exist for a short time.

Be used with gases in groups:Group A propaneGroup B ethyleneGroup C hydrogen

Having a temperature classification of:T1 450CT2 300CT3 200CT4 135CT5 100C

At an ambient temperature between 40 and+60C.

Note: the guaranteed operating temperature rangeof the BA488C Serial Text Display is 20 to +60C

This allows the BA488CF to be used with mostcommon industrial gases. The IECEx safetyparameters are identical to the ATEX parameters.

Special conditions for safe use in Zone 0In the unlikely event of installation in a Zone 0potentially explosive atmosphere, the BA488CSerial Text Display shall be installed such thateven in the event of rare incidents, an ignitionsource due to impact or friction between thealuminium enclosure at the rear of the instrumentmounting panel and iron/steel is excluded.

The IECEx certificate may be downloaded fromwww.beka.co.uk, www.iecex.com or requestedfrom the BEKA sales office.

A3.2 InstallationThe BA488CF IECEx and ATEX certifications haveidentical intrinsic safety parameters and installationrequirements. The ATEX system designrequirements described in section 5.1 of thismanual may therefore be used for IECExinstallations, but the local code of practice shouldalways be consulted.