TR BA678C User manual

Issue 6
13th June 2012
BA678C
Panel mounting
indicating temperature
transmitter
Issue 6
ul. Lech cka 14 ; 02-156 Warszawa Fax. [phone] b [email protected]
TR Automatyka Sp. z o. o. Tel. [phone] www.trautomatyka.pl

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1. Description
2. Documentation
3. Operation
3.1 Controls
4. Electrical system design
4.1 Use as a temperature indicator
5. Installation
5.1 Location
5.2 Installation procedure
5.3 EMC
6. Configuration
6.1 Configuration menu
6.1.1 Access
6.1.2 Summary of functions
6.2 Description of configuration menu functions
6.1.3 Transmitter input ‘InPut’
6.1.4 Thermocouple type ‘t.tYPE’
6.1.5 Units of digital display ‘dEG’
6.1.6 Display resolution ‘rESn’
6.1.7 Cold junction compensation ‘CJC’
6.1.8 Sensor fault analogue indication
‘FAuLT’
6.1.9 Configuration of 4/20mA output ‘CAL’
6.1.10 Configuration of bargraph display ‘bAr’
6.1.11 Access code ‘CodE’
6.1.12 Resistance thermometer type ‘r.tYPE’
6.1.13 Decimal point position ‘dP’
6.1.14 Lower input & display ‘in-Lo’
6.1.15 Higher input & display ‘in-Hi’
6.3 Configuration defaults
7. Configuration example
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 Scale marking
9.2 Tag number
9.3 Alarms
9.3.1 Solid state output
9.3.2 Alarm configuration
9.3.3 Alarm selection ‘Alr1’ & ‘Alr2’
9.3.4 Alarm enable ‘EnbL’
9.3.5 Setpoint adjustment ‘SP1’
9.3.6 Alarm function ‘’Hi.Lo’
9.3.7 Alarm output status ‘no.nC’
9.3.8 Hysteresis ‘HStr’
9.3.9 Alarm delay ‘dELA’
9.3.10 Alarm silence time ‘SiL’
9.3.11 Access setpoint ‘ACSP’
9.3.12 Adjusting alarm setpoints from
operational mode.
CONTENTS
The BA678C is CE marked to show compliance with the European EMC Directive 2004/108/EC

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1. DESCRIPTION
The BA678C is a panel mounting 4/20mA loop
powered temperature transmitter with a large easy to
read display. The instrument, which is HART
enabled, may be conditioned on-site to operate with
most common thermocouples and resistance
thermometers and will provide a linear 4/20mA output
proportional to temperature, plus a digital
temperature display. Voltage and resistance inputs
may be scaled allowing the BA678C to display
variables other than temperature such as position
and weight.
Optional factory fitted alarms provide two galvanically
isolated solid state outputs that may be
independently configured for high or low operation.
For installation in poorly illuminated areas, an
optional factory fitted loop powered display backlight
is available.
Fig 1 Simplified block diagram
2. DOCUMENTATION
This instruction manual describes the installation and
configuration of the BA678C Indicating Temperature
Transmitter.
The transmitter is HART Registered and is compliant
with HART protocol standard revision 7. HART
commissioning information is included in the
BA47X/67X Indicating Temperature Transmitter
HARTInterface Guide which may be downloaded
from www.beka.co.uk/manuals
3. OPERATION
Fig 1 shows a simplified diagram of the BA678C
Indicating Temperature Transmitter. The input,
which may be from a resistance thermometer,
thermocouple, or a dc voltage or resistance, is
digitised and transferred to the instrument processor
via an optical isolator. The processor linearises the
input signal, displays the resulting temperature in the
selected units and controls the 4/20mA output
current.
3.1 Controls
All functions of the transmitter may be configured via
the front panel push buttons – see Fig 2. Buttons
respond within 0.5 seconds of being operated and
unless continuously pushed the transmitter display
will return to the operating mode after 2 seconds.
In the operational mode, i.e. when the transmitter is
displaying the input signal, these push buttons have
the following functions:
Button Function
While this button is operated the transmitter
will show the display corresponding to 4mA
output.
▲While this button is operated the transmitter
will show the display corresponding to
20mA output.
+Transmitter displays output current in mA
followed by output as % of the range.
P + Transmitter displays HARTshort address
followed by firmware version number.
P + EEntry to configuration menu.
When fitted with optional alarms
P + Entry to alarm set point menu. See 9.3.11
E + Transmitter displays alarm 1 setpoint
E + Transmitter displays alarm 2 setpoint
P Activated alarm reverts to the non-alarm
condition for the configured alarm silence
time. See 9.3.10

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4. ELECTRICAL SYSTEM DESIGN
The BA678C is a smart HARTenabled loop
powered 4/20mA Indicating Temperature Transmitter.
For installation in poorly illuminated areas the
BA678C is available with an optional factory fitted
display backlight. No additional wiring of power
supply is required, but the minimum operating voltage
of the transmitter is increased as shown below.
without backlight 9.0 to 28V
with backlight 15.5 to 28V
Fig 2 Typical BA678C loop
When designing a transmitter loop it is necessary to
establish that the sum of the voltage drops caused by
the transmitter, load and the cable resistance is less
than the minimum supply voltage.
For the transmitter loop shown in Fig.2
Minimum operating voltage of BA678C 9.0V
without optional backlight.
Maximum voltage drop caused by 5.0V
250load.
(250x 20mA)
Maximum voltage drop caused by 0.2V
cable resistance.
(10x 20mA)
______
Total maximum voltage drop 14.2V
The power supply voltage must therefore be above
14.2V at all output currents.
4.1 Use as a temperature indicator
The BA678C may also be used as just a temperature
indicator by ignoring the instrument’s 4/20mA output
current. The load shown in Fig 2 may be omitted and
terminals 5 & 6 connected directly to the power
supply.
5. INSTALLATION
5.1 Location
The BA678C 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 at an
ambient temperature between –40ºC and +70ºC.
Please consult BEKA associates if high vibration is
anticipated.
Fig 3 shows the overall dimensions of the BA678C
and the panel cut-out. To achieve an IP66 seal
between the instrument enclosure and the panel, the
smaller cut-out must be used and the instrument
secured with four panel mounting clips.
The BA678C liquid crystal display has maximum
contrast when viewed from directly ahead and slightly
below the centre line of the instrument.
Fig 3 BA678C dimensions

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5.2 Installation Procedure
a. Insert the BA678C into the instrument panel
cut-out from the front of the panel with the
sealing gasket positioned as shown in Fig 4.
b. Fix panel mounting clips to opposite sides of
the instrument and tighten until the instrument
is secure. 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 as shown in Fig 4. To simplify
installation, the terminals are removable so
that panel wiring can be completed before the
instrument is installed.
Fig 4 Installation and terminal connections
5.3 EMC
The BA678C complies with the requirements of the
European EMC Directive 2004/108/EC. For specified
immunity, all wiring should be in screened twisted
pairs with the screens earthed at one point.
6. CONFIGURATION
The BA678C Indicating Temperature Transmitter
may be configured and calibrated via HARTdigital
communication, or configuration may be performed
using the menu accessed via the front panel push
buttons see Fig 3.
Configuration and calibration via HARTmay be
performed using a portable configurator connected
directly to the BA678C or proprietary configuration
software operating on a personal computer may be
used. In addition to the configuration functions
available via the transmitter push buttons, HART
communication enables loop calibration and custom
linearisation to be performed. Details of the HART
communication are contained in the BA47X/67X
Indicating Temperature Transmitter HARTInterface
Guide which may be downloaded from
www.beka.co.uk/manuals
6.1 Configuration menu
Throughout this manual the BA678C push buttons
are identified P E ▼▲and legends displayed by
the transmitter are shown within inverted commas
e.g. ‘CAL’ and ‘dEG’. Section 6.1.2 contains a
summary of each configuration function including a
cross reference to a more detailed description.
The functions contained in the configuration menu
vary depending upon the transmitter input selected,
see Figs 5, 6 & 7.
When the transmitter is being configured, the
transmitter 4/20mA output current is locked at the
value prior to entering the configuration menu.
When optional alarms are fitted additional functions
are added to the configuration menu which are
described in section 9.3.
6.1.1 Access
Access to the configuration menu is obtained by
operating the Pand Ebuttons simultaneously. If the
transmitter is not protected by an access code the
first parameter 'InPut’ will be displayed. If the
transmitter is protected by an access code, ‘CodE’
will be displayed first. Pressing Pwill allow the four
digit security code to be entered digit by digit using
the or button to adjust the flashing digit and Pto
move control to the next digit. When the correct code
has been entered, pressing Ewill cause the first
parameter ‘InPut’ to be displayed. If an incorrect
code is entered, or no button is pressed for ten
seconds, the transmitter will automatically return to
the operating mode.

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If the transmitter displays ‘LoC’ when the Pand E
buttons are operated simultaneously, the transmitter
push buttons have been locked by a HART
command - see the the BA47X/67X Indicating
Temperature Transmitter HARTInterface Guide
which may be downloaded from
www.beka.co.uk/manuals.
6.1.2 Summary of functions
The functions that may be configured vary depending
upon the input selected.
Thermocouple and RTD inputs
The BA678C will always display sensor temperature.
Configuration allows:
Digital display units and resolution to be selected.
Bargraph display to represent required part of the
digital displayed range.
4/20mA output current to have required input
range.
Voltage and resistance inputs
The BA678C can display the voltage or resistance
input in any engineering units.
Configuration allows:
Zero and span of digital display to be adjusted.
Bargraph display to represent required part of the
digital displayed range.
4/20mA output current to have required input
range.
Each of the functions in the configuration menu is
summarised below, including a cross-reference to a
more detailed description.
Transmitter Summary
display of function
‘InPut’ Transmitter input
Selects one of the following inputs:
Thermocouple ‘tHC’
3 wire RTD ‘3rtd’
4 wire RTD ‘4rtd’
Differential RTD ‘d_rtd’
Voltage ‘Volt’
3 wire resistance ‘3rES’
4 wire resistance ’4rES’
See section 6.2.1
The content of the configuration menu depends upon
which transmitter input is selected, see following
summary and Figs 5, 6 and 7.
For Thermocouple Input – see Fig 5
Transmitter Summary
display of function
‘t.tYPE’ Thermocouple type
Selects 1 of 8 common types of
thermocouple.
See section 6.2.2
‘dEG’ Units of digital display
Selects 1 of 4 units of temperature.
See section 6.2.3
‘rESn’ Display resolution
Selects low or high display resolution.
See section 6.2.4
‘CJC’ Cold junction compensation
Turns thermocouple cold junction
compensation on or off.
See section 6.2.5
‘FAuLt’ Sensor fault analogue indication
Selects 1 of 3 under/over range output
currents to indicate that a sensor fault has
been detected. Analogue fault indication
may be disabled.
See section 6.2.6
‘CAL’ Configuration of 4/20mA output
Defines transmitter input at which
transmitter output is 4 & 20mA.
See section 7.2.7
‘bAr’ Configuration of bargraph display
Defines digital display at which bargraph
is zero and full scale.
See section 6.2.8
‘CodE’ Access code for configuration menu
Enters four digit configuration menu
access code. Default code 0000 disables
this function.
See section 6.2.9

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For Resistance Thermometer (RTD) Input see Fig 6
Transmitter Summary
display of function
‘r.tYPE’ Resistance thermometer type
Selects Pt100 or Pt1000 sensor
See section 6.2.10
‘dEG’ Units of digital display
Selects 1 of 4 units of temperature.
See section 6.2.3
‘rESn’ Display resolution
Selects low or high display resolution.
See section 6.2.4
‘FAuLt’ Sensor fault analogue indication
Selects 1 of 3 under/over range output
currents to indicate that a sensor fault has
been detected. Analogue sensor fault
indication may be disabled.
See section 6.2.6
‘CAL’ Configuration of 4/20mA output
Defines transmitter input at which
transmitter output is 4 & 20mA.
See section 6.2.7
‘bAr’ Configuration of bargraph display
Defines digital display at which bargraph
is zero and full scale.
See section 6.2.8
‘CodE’ Access code for configuration menu
Enters four digit configuration menu
access code. Default code 0000 disables
this function.
See section 6.2.9
For Voltage and Resistance Inputs – see Fig 7
Transmitter Summary
display of function
‘dP’ Decimal point position
Defines position of displayed decimal
point.
See section 6.2.11
‘in-Lo’ Lower input and display
Defines lower voltage or resistance input
‘inVAL’ and corresponding digital display
‘diSP’.
See section 6.2.12
‘in-Hi’ Higher input and display
Defines higher voltage or resistance input
‘inVAL’ and corresponding digital display
‘diSP’.
See section 6.2.13
‘CAL’ Configuration of 4/20mA output
Defines the transmitter input at which
transmitter output is 4 & 20mA.
See section 6.2.7
‘bAr’ Configuration of bargraph display
Defines digital display at which bargraph
is zero and full scale.
See section 6.2.8
‘CodE’ Access code for configuration menu
Enters four digit configuration menu
access code. Default code 0000 disables
this function. See section 6.2.9

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6.2 Description of configuration menu
functions
This section contains a detailed description of each
function in the configuration menu. It should be read
in conjunction with Figs 5, 6 & 7.
6.2.1 Transmitter input ‘InPut’
This function enables the BA678C indicating
temperature transmitter to be conditioned to operate
with a thermocouple, 3 or 4 wire resistance
thermometer, voltage or 3 or 4 wire resistance input.
A differential resistance thermometer input may also
be selected. A differential thermocouple input is
achieved by selecting the thermocouple input in this
function and turning the cold junction compensation
off in the CJC function – see 6.2.5.
Sensor Transmitter
display
Thermocouple ‘tHC’
3 wire RTD ‘3rtd’
4 wire RTD ‘4rtd’
Differential RTD ‘d_rtd’
Voltage ‘VoLt’
3 wire resistance ‘3rES’
4 wire resistance ’4rES’
The ‘InPut’ function is the first function displayed
when entering the configuration menu, or it may be
selected from within the menu by operating the or
button. To enter the function press Pto reveal
the existing setting which may be changed using the
or button. When the required input has been
selected press Eto enter the selection and return to
the ‘InPut’ prompt in the configuration menu.
6.2.2 Thermocouple type ‘t.tYPE’
This function enables one of eight common
thermocouples to be selected. The following table
shows the thermocouple types, indicator display and
the operating temperature range.
THC BA678C Temperature
Type Display range oC
B ‘b’ 200 to 1820
E ‘E’ -200 to 1000
J ‘J’ -210 to 1200
K ‘H’ -200 to 1372
N ‘n’ -200 to 1300
R ‘r’ -50 to 1768
S ‘S’ -50 to 1768
T ‘t’ -200 to 400
The ‘t.tYPE’ function may be selected from within the
menu by operating the or button. To enter the
function press Pwhich will reveal the existing setting
which may be changed using the or button.
When the required thermocouple has been selected,
press Eto enter the selection and return to the
‘t.tYPE’ prompt in the configuration menu.
6.2.3 Units of digital display ’dEG’
The transmitter digital display may be in one of four
units of temperature.
Units Transmitter Display
oC oC
oF oF
r r
K H
When oC or oF are selected the units of measurement
are shown at the top left hand corner of the display
when the transmitter is in the operating mode.
The ‘dEG’ function may be selected from within the
menu by operating the or button. To enter the
function press Pwhich will reveal the existing setting
which may be changed using the or button.
When the required units have been selected, press E
to enter the selection and return to the ‘dEG’ prompt
in the configuration menu.
6.2.4 Display resolution ‘rESn’
This function defines the resolution of the transmitter
display but does not affect the resolution of the
4/20mA output current.
Resolution Transmitter Display
Lo 0 0 0 0 0
Hi 0 0 0 0.0
The ‘rESn’ function may be selected from within the
menu by operating the or button. To enter the
function press Pwhich will reveal the existing setting
which may be changed using the or button.
When the required resolution has been selected,
press Eto enter the selection and return to the ‘rESn’
prompt in the configuration menu.
6.2.5 Cold junction compensation ‘CJC’
The temperature of the thermocouple cold junction,
which is the transmitter input terminals, is measured
and added to the thermocouple output so that the
transmitter displays and transmits the hot junction
temperature. If cold junction compensation is not
required e.g. for differential measurements with two
thermocouples, this function allows it to be turned off.
The ‘CJC’ function may be selected from within the
configuration menu by operating the or button.
To enter the function press Pwhich will reveal the
existing setting which may be changed using the 
or button. When set as required, press Eto enter
the selection and return to the ‘CJC’ prompt in the
configuration menu.

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6.2.6 Sensor fault analogue indication ‘FAuLt’
The sensor fault analogue indication function appears
in the menu when the transmitter is configured for a
resistance thermometer or a thermocouple input.
When a fault is detected the transmitter’s 4/20mA
output current is set to the specified under or over
range fault value and the transmitter’s digital display
flashes as shown below. One of three fault currents
may be selected, or the fault indication may be turned
off. Irrespective of how the function is set the
transmitter display will flash when a sensor fault is
detected.
Selected Output Transmitter
fault current current display
‘oFF’ No fault indication Flashes
‘dn3.6’ 3.6mA *Flashes
‘dn3.8’ 3.8mA Flashes
‘uP 21’ 21.0mA Flashes
* Not recommended when HART
communication is used.
The ‘FAuLt’ function may be selected from within the
configuration menu by operating the or button.
To enter the function press Pwhich will reveal the
existing setting which may be changed using the 
or button. When set as required, press Eto enter
the selection and return to the ‘FAuLT’ prompt in the
configuration menu.
The typical detection thresholds and approximate
response times are:
Thermocouple > 5k10 sec
RTD sensor < 5>5001 sec
RTD sense leads > 5010 sec
In the time between a fault developing in an RTD
sense lead or a thermocouple and the fault being
detected, the transmitter output and display may drift
from the last correct measured value.
6.2.7 Configuration of 4/20mA output ‘CAL’
This function defines the relationship between the
transmitter input and the 4/20mA output current.
‘Zero’ defines the transmitter input at which the
output is 4mA and ‘Span’ defines the input at which
the output is 20mA.
This function does not affect the transmitter display
which is fixed for thermocouple and resistance
thermometer inputs and adjusted via the ‘in-Lo and
‘in-Hi’ functions for resistance and voltage inputs.
The ‘CAL’ function may be selected from within the
menu by operating the or button. To enter the
function press Pwhich will display the ‘ZEro’ function
in the sub-menu, pressing Pagain will reveal the
existing transmitter input at which the transmitter
output current is 4mA. Input is shown in units which
depend upon how the transmitter input ‘InPut’ and
display ‘dEG’ have been configured, as shown
below:
Configured Input
transmitter input shown as
Thermocouple oC, oF, K or r
Resistance thermometer oC, oF, K or r
Voltage mV
Resistance Ohms
The input, at which the transmitter output current is
4mA, may be changed using the or button to
adjust the flashing digit and the Pbutton to move
control to the next digit. When the required input has
been selected, press Eto enter the selection and
return to the ‘ZEro’ prompt in the sub menu.
The ‘SPAn’ function, which defines the input at which
the transmitter current output is 20mA, may be
selected from within the sub-menu by operating
either the or button. To enter the function press
Pwhich will reveal the existing transmitter input at
which the transmitter output current is 20mA. Again
the input will be shown in units which depend upon
how the transmitter has been configured.
The input, at which the transmitter output current is
20mA, may be changed using the or button to
adjust the flashing digit and the Pbutton to move
control to the next digit. When the required input has
been selected, press Etwice to enter the selection
and return to the ‘CAL’ prompt in the configuration
menu.
Note: When configured for a voltage input, operating
the Pbutton when the 0.1mV digit is flashing in the
‘Zero’ or ‘SPAn’ sub-menus increases the input
resolution to 0.01mV which is indicated by the display
colon being activated. When the required input has
been selected, pressing Eenters the selection and
returns the transmitter to the ‘ZEro’ or ‘SPAn’ prompt
in the sub-menu.
If, when configured for a voltage or resistance input
the displayed decimal point has been set to
autorange, it may be necessary to manually position
the decimal point before adjusting ‘ZEro’ or ‘SPAn’.
This can be achieved by repeatedly operating the P
button until the activated decimal point flashes, the
decimal point can then be positioned using either the
or button. Pressing the Pbutton again will
return control to one of the digits.

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6.2.8 Configuration of bargraph display ‘bAr’
This function contains three sub-functions that justify
the bargraph display and define the relationship
between the bargraph and the transmitter digital
display.
Sub-function ‘b.tYPE’ enables the bargraph to be left,
centre or right justified, or to be turned off. Sub-
functions ‘bArLo’ and ‘bArHi’ define the transmitter
digital display at which the bargraph starts and is at
full scale.
The ‘bAr’ function may be selected from within the
configuration menu by operating the or button.
To enter the function press Pwhich will display the
‘b.tYPE’ sub-function, pressing Pagain will reveal the
existing bargraph justification. The or button
will scroll through the four options, when the required
justification is displayed, pressing Ewill enter the
selection and return the display to the ‘b.tYPE’
prompt in the sub-menu from which ‘bArLo’ may be
selected using the or button.
‘bArLo’ defines the transmitter digital display at which
the bargraph starts, to enter the function press P
which will reveal the existing setting. The display
may be changed using the or button to adjust
the flashing digit and the Pbutton to move control to
the next digit. When the required starting display has
been selected, press Eto return to the ‘bArLo’ prompt
in the sub-menu from which the ‘bArHi’ function may
be selected.
‘bArHi’ defines the transmitter digital display at which
the bargraph is full scale, to enter the function press
Pwhich will reveal the existing setting. The display
may be changed using the or button to adjust
the flashing digit and the Pbutton to move control to
the next digit. When the required display has been
selected, press Etwice to return to enter the new
values and return to the ‘bAr’ prompt in the
configuration menu.
Note: If, when configured for a voltage or resistance
input the displayed decimal point has been set to
autorange, it may be necessary to manually position
the decimal point before adjusting ‘bArLo’ or ‘bArHi’.
This can be achieved by repeatedly operating the P
button until the activated decimal point flashes, the
decimal point can then be positioned using either the
or button. Pressing the Pbutton again will
return control to one of the digits.
6.2.9 Access code for configuration menu
‘CodE’
Access to the configuration menu may be protected
by a four digit security code which must be entered to
gain access. New instruments are supplied
configured with the default code 0000 which allows
unrestricted access to the menu.
To enter a new access code select ‘CodE’ in the
configuration menu by operating the or button.
To enter the function press Pwhich will reveal the
current access code with one digit flashing. The code
may be changed using the or button to adjust
the flashing digit and the Pbutton to move control to
the next digit. When the required code has been
selected, press Eto enter the selection and return to
the ‘CodE’ prompt in the configuration menu. The
revised access code will be activated when the
transmitter is returned to the operating mode.
If the access code is lost please contact BEKA
associates.
6.2.10 Resistance thermometer type ‘r.tYPE’
This function configures the BA678C to operate with
a Pt100 or Pt1000 resistance thermometer input.
The ‘r.tYPE’ function may be selected from within the
configuration menu by operating the or button.
To enter the function press Pwhich will reveal the
existing setting which may be changed using the 
or button.
Resistance Transmitter
thermometer display
Pt100 100r
Pt1000 1000r
When the required resistance thermometer has been
selected, press Eto enter the selection and return to
the ‘r.tYPE’ prompt in the configuration menu.
6.2.11 Decimal point position ‘dP’
This function defines the position of the displayed
decimal point when the transmitter is configured for a
voltage or a resistance input.
This function does not appear in the configuration
menu when the transmitter is configured for a
thermocouple or a resistance thermometer input.
The ‘dP’ function may be selected from within the
menu by operating the or button. To enter the
function press Pto reveal the existing position of the
decimal point which may be moved to the required
fixed position, omitted, or set to autorange by
operating the or button. Autorange, which is
selected when all the decimal points are activated,
ensures that the transmitter numeric display is always
shown with maximum resolution irrespective of the
value. When set as required, press Eto enter the
selection and return to the ‘dP’ prompt in the
configuration menu.

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6.2.12 Lower input & display ‘in-Lo’
This function, which only appears in the menu when
the transmitter is configured for a voltage or
resistance input, defines the transmitter lower input
voltage or resistance ‘inVAL’ and the corresponding
transmitter digital display ‘diSP’.
This function does not affect the transmitter output
current which is defined by the ‘CAL’ function.
The ‘in-Lo’ function may be selected from within the
configuration menu by operating the or button.
To enter the function press Pwhich will display
‘inVAL’ in the sub-menu, pressing Pagain will reveal
the existing transmitter lower input voltage or
resistance. ‘InVAL’ is shown in units that depend
upon how the transmitter input ‘inPut’ has been
configured, as shown below:
Configured ‘inVAL’
transmitter input units resolution
Voltage mV 0.1 or 0.01mV
Resistance 0.1
‘inVAL’ may be adjusted using the or button to
adjust the flashing digit and the Pbutton to move
control to the next digit. When configured for a
voltage input, operating the Pbutton when the 0.1mV
digit is flashing increases the resolution to 0.01mV
which is indicated by the display colon being
activated. When the required input has been
selected, press Eto enter the selection and return to
the ‘inVAL’ prompt in the sub-menu.
‘diSP’ which is the transmitter display corresponding
to ‘inVAL’ may be selected from within the sub-menu
by operating either the or button. To enter the
function press Pwhich will reveal the existing lower
transmitter display. The display may be changed
using the and buttons to adjust the flashing digit
and the Pbutton to move control to the next digit.
When the required transmitter display has been
selected, press Etwice to enter the selection and
return to the configuration menu.
Note: When the displayed decimal point has been
set to autorange, it may be necessary to manually
position the decimal point before adjusting ‘inVAL’.
This can be achieved by repeatedly operating the P
button until the activated decimal point flashes, the
decimal point can then be positioned using either the
or button. Pressing the Pbutton again will
return control to one of the digits.
6.2.13 Higher input & display ‘in-Hi’
This function which only appears in the menu when
the transmitter is configured for a voltage or
resistance input, defines the transmitter higher input
voltage or resistance ‘inVAL’ and the corresponding
transmitter digital display ‘diSP’.
This function does not affect the transmitter output
current which is defined by the ‘CAL’ function.
The ‘in-Hi’ function may be selected from within the
configuration menu by operating the or button.
To enter the function press Pwhich will display
‘inVAL’ in the sub-menu, pressing Pagain will reveal
the existing transmitter higher input voltage or
resistance. ‘InVAL’ is shown in units which depend
upon how the transmitter input ‘inPut’ has been
configured, as shown below:
Configured ‘inVAL’
transmitter input units resolution
Voltage mV 0.1 or 0.01mV
Resistance 0.1
‘inVAL’ may be adjusted using the or button to
adjust the flashing digit and the Pbutton to move
control to the next digit. When configured for a
voltage input, operating the Pbutton when the 0.1mV
digit is flashing increases the resolution to 0.01V
which is indicated by the display colon being
activated. When the required input has been
selected, press Eto enter the selection and return to
the ‘inVAL’ prompt in the sub-menu.
‘diSP’ which is the transmitter display corresponding
to ‘inVAL’ may be selected from within the sub-menu
by operating either the or button. To enter the
function press Pwhich will reveal the existing higher
transmitter display. The display may be changed
using the or button to adjust the flashing digit
and the Pbutton to move control to the next digit.
When the required transmitter display has been
selected, press Etwice to enter the selection and
return to the configuration menu.
Note: When the displayed decimal point has been
set to autorange, it may be necessary to manually
position the decimal point before adjusting ‘inVAL’.
This can be achieved by repeatedly operating the P
button until the activated decimal point flashes, the
decimal point can then be positioned using either the
or button. Pressing the Pbutton again will
return control to one of the digits.

12

13

14

15
6.3 Default configuration
If the transmitter’s configuration is not specified at the
time of ordering, the instrument will be configured as
follows but can easily be reconfigured on-site.
Function Factory default
Transmitter input ‘InPut’ 3 wire RTD
Sensor type ‘t.tYPE’ Pt100
Units of digital display ‘dEG’ ºC
Display resolution ‘rESn’ Low
Sensor fault ‘FAuLt’ Off
4/20mA output ‘CAL’ 0.0 to 100.0
Bargraph display ‘bAr’ Left hand
justification.
Bargraph starts at
digital display 0.0
and finishes at
digital display
100.0
Access code ‘CodE’ 0000 which
disables this
function.

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7. CONFIGURATION EXAMPLE
In this example a BA678C indicating temperature
transmitter is required to display temperature in
degrees Celsius with maximum resolution. The
temperature sensor is a 3 wire Pt100 resistance
thermometer and the 4/20mA transmitter output is
required to representing –10 to +250oC. . A left hand
justified bargraph representing 100.0 to 200.0oC is
required. Resistance thermometer failure is to be
indicated by an overrange output current of 21.0mA.
After configuration access to the configuration menu
is to be protected by code 1209.
Configuration is performed using the front panel push
buttons – see Fig 3.
The transmitter configuration may also be performed
via HARTcommunication from a local or remote
configurator. The HARTcommunication protocol
includes additional functions allowing the complete
temperature loop, including the temperature sensor
and the transmitter load, to be calibrated - see the
BA47X/67X Indicating Temperature Transmitter
HARTInterface Guide which may be downloaded
from www.beka.co.uk/manuals
Step 1 Access the configuration menu &
select the type of input.
See: Fig 6 and section 6.2.1
New BA678C indicating temperature
transmitters are supplied conditioned
with default access code ‘0000’ that
allows unrestricted access to the
configuration menu.
To enter the configuration menu press
buttons Pand Esimultaneously which
will cause the first prompt ‘InPut’ to be
displayed. Press Pto enter the function
and the transmitter will display the
current type of input. To configure the
transmitter to operate with a three wire
resistance thermometer press the or
button until ‘3rtd’ is displayed. When
selected press Eto enter the selection
and return to the ‘InPut’ prompt in the
configuration menu.
Step 2 Select resistance thermometer type
See: Fig 6 and section 6.2.10
Using the or button select the
‘r,tYPE’ prompt from the configuration
menu and press Pto enter the function
which enables the type of resistance
thermometer to be selected. The
transmitter will display the existing type
of resistance thermometer, using the 
or button select ‘100r’ which is the
required Pt100 sensor. Enter the
selection by pressing the Ebutton that
will return the display to the ‘r.tYPE’
prompt in the configuration menu.
Step 3 Select units of digital display
See: Fig 6 and section 6.2.3
Using the or button select ‘dEG’
from the configuration menu and press P
to enter the function which enables the
digital display units of measurement to
be selected. Using the or button
scroll through the options and select ‘ºC’
which represents degrees Celsius.
Press Eto enter the selection and return
the transmitter display to the ‘dEG’
prompt in the configuration menu.
Step 4 Select display resolution
See: Fig 6 and section 6.2.4
Using the or button select ‘rESn’
from the configuration menu and press P
to enter the function which determines
the resolution of the digital display.
Using the or button select ‘Hi’ to
provide the required 0.1 resolution
display. Press Eto enter this selection
and return the display to the ‘rESn’
prompt in the configuration menu.
Step 5 Sensor fault detection
See: Fig 6 and section 6.2.6
Using the or button select ‘FAuLt’,
the input sensor fault detection function,
from the configuration menu and press
P. Using the or button scroll
through the options and select ‘uP 21’
which forces the output current to
21.0mA when a sensor failure is
detected. Enter the selection by
pressing Ewhich will also return the
transmitter display to the ‘FAuLt’ prompt
in the configuration menu.

17
Step 6 Configuration of 4/20mA output
See: Fig 6 and section 6.2.7
The BA678C transmitter digital display
at which the transmitter output current is
4mA and 20mA is defined by the ‘CAL’
function which contains two sub-
functions.
Using the or button select ‘CAL’
from the configuration menu and press P
which will show the ‘ZEro’ sub-function
prompt. Press Pagain to enter this sub-
function, which will reveal the existing
digital display at which the transmitter
output current is 4mA. Adjust the
display to the required –0010.0 using the
or button to adjust the flashing digit
and the Pbutton to move control to the
next digit. A negative display is
achieved by scrolling the most
significant digit below zero using the 
button. When set press Eto enter the
new value and return to the ‘ZEro’ sub-
function prompt from which the ‘SPAn’
sub-function, which defines the display
at which the output is 20mA, may be
selected using the or button.
Press Pto enter this sub-function, which
will reveal the existing digital display at
which the transmitter output current is
20mA. Adjust the display to 0250.0
using the or button to adjust the
flashing digit and the Pbutton to move
control to the next digit.
Finally press Etwice, first to enter the
selection and return to the ‘SPAn’ sub-
function prompt, and again to return to
the ‘CAL’ function prompt in the
configuration menu.
Step 7 Configuration of bargraph display
See: Fig 6 and section 6.2.8
This function contains three sub-
functions that justify the bargraph
display and define the transmitter digital
display at which the bargraph starts and
finishes.
Using the or button select ‘bAr’
from the configuration menu and press P
which will show the ‘b.tYPE’ sub-function
prompt. Press Pagain to enter this sub-
function, which will reveal the existing
bargraph justification. Using the or 
button scroll through the options and
select ‘LEFt’ which will start the
bargraph on the left hand side of the
display. Press Eto enter the selection
and return to the ‘b.tYPE’ sub-function
prompt from which, using the or 
button, the ‘bArLo’ sub-function may be
selected. Press Pto enter the ‘bArLo’
sub-function which will reveal the
existing digital display at which the
bargraph starts. Set the display to
0100.0 using the or button to
adjust the flashing digit and the Pbutton
to move control to the next digit. When
set, press Eto enter the new value and
return to the ‘bArLo’ sub-function prompt
from which the ‘bArHi’ sub-function may
be selected. Press Pto enter the
‘bArHi’ sub-function which will reveal the
existing digital display at which the
bargraph finishes. Set the display to
0200.0 using the or button to
adjust the flashing digit and the Pbutton
to move control to the next digit.
Finally press Etwice, first to enter the
selection and return to the ‘bArHi’ sub-
function prompt, and again to return to
the ‘bAr’ function prompt in the
configuration menu.
Step 8 Enter the configuration
menu access code.
See Fig 6 and section 6.2.9
This function defines the four digit code
that must be entered to obtain access to
the BA678C transmitter’s configuration
menu.
Using the or button select the
‘CodE’ prompt from the configuration
menu and press Pwhich, for a new
instrument, will show the default code
‘0000’ with the first digit flashing. Using
the or button to adjust the flashing
digit and the Pbutton to transfer control
to the next digit, set the display to 1209.
Press Etwice to enter the new access
code and return the BA678C to the
display mode via the ‘CodE prompt.
This completes the instrument
configuration. The BA678C transmitter
will now function as specified at the
beginning of this example. Access to
the configuration is protected by code
1209 which must be entered each time a
change is made.

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8. MAINTENENCE
The BA678C indicating temperature transmitter
should only be maintained by trained competent
personnel.
8.1 Fault finding during
commissioning
If a BA678C fails to function during commissioning
the following procedure should be followed:
Symptom Cause Check
No display or
output current
Incorrect wiring
Low supply
voltage
Wiring
That voltage
between terminals
5 & 6 is between 9
& 28V at all output
currents. Terminal
5 positive.
or between
15 .5 & 28V at all
output currents if
optional backlight
is fitted.
Digital display is
over or under
range showing
9.9.9.9.9
or
-9.9.9.9.9
with all decimal
points flashing.
Incorrect wiring of
THC or RTD input
Input is outside
specified range for
voltage or
resistance input.
Wiring and input
configuration.
Reconfigure digital
display.
Bargraph is over
or under range.
with scale flashing,
bargraph
displaying all or
just one segment.
Input is outside
specified range for
bargraph.
Reconfigure
bargraph display.
Digital display &
bargraph flashing
and 4/20mA fixed
at 3.6, 3.8 or
21.0mA
Sensor fault
detection has
been activated.
Sensor and input
wiring.
8.2 Fault finding after
commissioning
ENSURE PLANT SAFETY BEFORE STARTING
MAINTENANCE
If a BA678C fails after it has been functioning
correctly the following procedure should be followed:
Symptom Cause Check
No display or
output current
Wiring or power
supply fault.
Wiring
That voltage
between terminals
5 & 6 is between 9
& 28V. Terminal 5
positive.
or
15 .5 & 28V if
optional backlight
is fitted.
Digital display &
bargraph flashing
and 4/20mA fixed
at 3.6, 3.8 or
21.0mA
Sensor fault
detection has
been activated.
Sensor and input
wiring.
If this procedure does not reveal the cause of the
fault we recommend that the transmitter is replaced.

19
8.3 Servicing
We recommend that faulty BA678C indicating
temperature transmitters are returned to BEKA
associates or to our local agent for repair.
8.4 Routine maintenance
The mechanical and electrical condition of the
transmitter should be regularly checked. Initially an
annual inspection is recommended, but the
inspection frequency should be adjusted to suit the
environmental conditions.
8.5 Guarantee
Transmitters which fail within the guarantee period
should be returned to BEKA associates or our local
agent. It is helpful if a brief description of the fault
symptoms is provided.
8.6 Customer comments
BEKA associates is always pleased to receive
comments from customers about our products and
services. All communications are acknowledged and
whenever possible, suggestions are implemented.
9. ACCESSORIES
9.1 Scale marking
BA678C transmitters are fitted with a blank
escutcheon around the liquid crystal display. If
specified when the instrument is ordered, this can be
supplied printed with units of measurement and a
scale for the horizontal bargraph.
9.2 Tag number
The BA678C can be supplied with a thermally printed
tag number on the rear panel adjacent to the
terminals.
9.3 Alarms
The BA678C can be supplied with two solid state
single pole alarm outputs that may be independently
programmed as high or low alarms with normally
open or normally closed outputs. Fig 8 illustrates the
conditions available and shows which are fail safe,
i.e. in the alarm condition the output is open.
WARNING
Alarms should not be used for critical
safety applications such as a shut down
system.
Fig 8 Alarm outputs
When an alarm is activated an annunciator appears
on the left hand side of the BA678C display. This
shows which alarm has been activated and will flash
if the alarm is delayed or silenced.
Programmable functions for each alarm include
adjustable setpoint, hysteresis, alarm delay and
alarm accept.

20
9.3.1 Solid state output
Each alarm has a galvanically isolated single pole
solid state switch output as shown in Fig 9. The
outputs are polarised and current will only flow in
one direction. Terminals 8 and 10 should be
connected to the positive side of the supply.
Ron = 5ohms + 0.6V
Roff = greater than 180k
Note: Because of the series protection diode some
test meters may not detect a closed alarm output.
Fig 9 Equivalent circuit of each alarm output
Fig 10 Typical alarm application
9.3.2 Alarm configuration
Alarm configuration may be performed via the
HARTdigital communication, see the BA47X/67X
Indicating Temperature Transmitter HARTInterface
Guide which may be downloaded from
www.beka.co.uk/manuals for details. Alternatively
configuration may be performed using the
configuration menu which is accessed via the front
panel push buttons, see Fig 3.
When a BA678C indicating temperature transmitter is
supplied with optional alarms the conditioning menu
is extended as shown in Fig 11. The additional
alarm functions appear between 'bAr' and 'CodE' in
the configuration menu. For simplicity Fig 11 only
shows the additional sub-functions for alarm 1, but
alarm 2 has identical sub-functions.
The following table summarises each of the alarm
configuration functions and includes a cross
reference to more detailed information. Again only
the functions for alarm 1 are listed, but alarm 2 has
identical functions.