background image

5.3.2  Display units  'dEg'

The transmitter display may be in degrees
centigrade or Fahrenheit.  To check or change the
display units select 'dEg' from the sub-menu and
press 

P

 to reveal the current setting.  The setting

may be changed by pressing the 

Up

 or 

Down

button. When the required units are displayed,
press 

E

 to return to the sub-menu.

5.3.3 Display resolution  'rESn'

The output of each type of thermocouple can be
displayed with high or low resolution as shown
below.   Low resolution can improve the readability
of a noisy or rapidly changing display, but does not
degrade the performance of the 4/20mA analogue
output.  High resolution is only available when the
transmitter is displaying temperature in 

o

C. When 

o

F

is selected the resolution is always one degree.

To check or change the display resolution select
'rESn' from the sub-menu and press 

P

 to reveal the

current setting.  The setting may be changed by
pressing the 

Up

 or 

Down

 button. When the required

resolution has been selected, press 

E

 to return to

the sub-menu.

                            Display Resolution
     Type        Low (Lo)            High (Hi)

E

1

o

C

0.1

o

C

J

1

o

C

0.1

o

C

K

1

o

C

0.2

o

C  *

N

1

o

C

0.2

o

C  *

R

1

o

C

0.4

o

C  *

T

1

o

C

0.1

o

C

   Pallaplat

1

o

C

0.2

o

C  *

      * Worst case high resolution figures are

quoted; at most temperatures resolution will
be greater.

5.3.4 Cold junction compensation  'CJC'

The temperature of the transmitter input terminals,
which is the thermocouple cold junction,  is
measured and added to the output from the
thermocouple so that the transmitter displays and
transmits the temperature relative to zero degrees
centigrade or Fahrenheit.  If cold junction
compensation is not required, e.g. for differential
measurement with two thermocouples, this function
enables the cold junction compensation to be turned
off.
To turn the cold junction compensation on or off
select 'CJC' from the sub-menu and press 

P

 to

reveal the current status.  The setting may be
changed by pressing the 

Up

 or 

Down

 button. When

set as required press 

E

 to return to the sub-menu.

5.3.5  Input open circuit drive  'burn'

If the thermocouple fails and becomes open circuit,
the transmitter can be conditioned to drive the
display and the 4/20mA output current up or down
into a safe condition.  Alternatively the drive may be
turned off which will result in the display and the
4/20mA output current drifting towards zero. 
To check or change the input open circuit drive
select 'burn' from the sub-menu and press 

P

 to

reveal the current setting.  The setting may be
changed by pressing the 

Up

 or 

Down

 button. When

the required setting has been selected, press 

E

 to

return to the sub-menu.

5.4  For resistance thermometer inputs

5.4.1 Types of resistance thermometer 'tYPE'

The transmitter may be conditioned to accept
3-wire, 4-wire or differential Pt100 resistance
thermometers.  
After selecting resistance thermometer input from
the 'InPut' sub-menu,  press 

P

 to reveal the 'tYPE'

sub-menu. Press 

P

 again to display the current

type of resistance thermometer which may be
changed by scrolling through the menu using the 

Up

or 

Down

 buttons.  When the required type is

displayed, press 

E

 to return to the sub-menu.

5.4.2  Display units  'dEg'

The transmitter display may be in degrees
centigrade or Fahrenheit.  To check or change the
display units select 'dEg' from the sub-menu and
press 

P

 to reveal the current setting.  The setting

may be changed by pressing the 

Up

 or 

Down

button. When the required unit is displayed, press 

E

to return to the sub-menu.

5.4.3 Display resolution  'rESn'

The output of the resistance thermometer can be
displayed with high or low resolution as shown
below.   Low resolution can improve the readability
of a noisy or rapidly changing display, but does not
degrade the performance of the 4/20mA analogue
output.  High resolution is only available when the
transmitter is displaying temperature in 

o

C. When 

o

F

is selected the display resolution is always one
degree.

To check or change the display resolution select
'rESn' from the sub-menu and press 

to reveal the

current setting.  The setting may be changed by
pressing the 

Up

 or 

Down

 button. When the required

resolution has been selected, press 

E

 to return to

the sub-menu.

      11

Summary of Contents for BA578C

Page 1: ...Issue 4 26th September 2008 BA578C panel mounting indicating temperature transmitter issue 4...

Page 2: ...eferences 5 8 1 Conditioning internal references 5 8 2 Voltage input reference 5 8 3 3 wire RTD reference 5 8 4 4 wire RTD reference 5 8 5 Output current reference 6 Trim Menu 6 1 Calibration procedur...

Page 3: ...ions of Section 5 you will find information on setting up for Section 6 3 Themocouple input Section 6 4 Resistance thermometer input Section 6 5 Voltage input A word of warning Section 5 8 explains ho...

Page 4: ...the 4 20mA output current The transmitter and the optional alarms are powered from the 4 20mA current loop but the optional display backlight requires a separate supply Each time power is applied to...

Page 5: ...sed in a robust aluminium enclosure with a polyester front panel and Noryl bezel The front panel provides IP65 protection and a gasket seals the joint between the instrument and the panel The transmit...

Page 6: ...are contained in section 6 which also describes periodic calibration When the transmitter is fitted with alarms additional functions are added to the programme menu These are described in section 10...

Page 7: ...value Each of the functions in the Programme Menu is described in the following summary with a cross reference to more detailed information Figs 5A and 5B illustrate the location of each function wit...

Page 8: ...8...

Page 9: ...9...

Page 10: ...st be entered to gain access to the programme and the trim menus Default code 0000 disables the security function and allows unrestricted access to all functions in the programme and trim menus See se...

Page 11: ...to the sub menu 5 3 5 Input open circuit drive burn If the thermocouple fails and becomes open circuit the transmitter can be conditioned to drive the display and the 4 20mA output current up or down...

Page 12: ...xt digit When the least significant digit has been adjusted press E to return to the dISP prompt 5 5 3 High input display calibration In HI This function defines the higher voltage input and the corre...

Page 13: ...ned to the display mode If the security code is lost access to the Programme and Trim Menus can be obtained by putting the internal security link in the override position see Fig 6 The security code c...

Page 14: ...mitters may be calibrated in a workshop Select 3rtd from the Cond sub menu and press P The transmitter will display scrolling decimal points while the reference is being updated followed by Ent prior...

Page 15: ...ly trimmed at the bottom of the input range To make the adjust ment connect a calibrator to the transmitter input terminals to simulate minimum input or place the primary element in a vessel at the mi...

Page 16: ...se to full scale The current security code is 1209 The example is divided into two sections Steps 1 to 10 explain how to condition the transmitter and to calibrate the 4 20mA output using the internal...

Page 17: ...may be calibrated by cooling and heating the thermocouple to 10 and 240o C This is the preferred method for routine calibration Step 11 Entering the trim menu Enter the trim menu by simultaneously pr...

Page 18: ...display mode 8 MAINTENANCE 8 1 Fault finding during commissioning If the BA578C transmitter fails to function during commissioning the following procedure should be followed Symptom Cause Solution No...

Page 19: ...any instrument which fails We recommend that suspect instruments are returned to BEKA associates or our local agent for repair 8 4 Guarantee Transmitters which fail within the guarantee period should...

Page 20: ...with a thermally printed tag strip on the rear panel with any legend containing up to 35 alphanumeric characters This strip is not visible from the front of the instrument after installation 10 ALARM...

Page 21: ...alarm parameters See section 10 3 1 SP1 Alarm setpoint 1 Adjusts the alarm setpoint The alarm is activated when the indicator display equals the setpoint The setpoint can also be adjusted directly fro...

Page 22: ...22 Fig 11 Programme structure for optional alarms...

Page 23: ...ut status select no nc from the alarm sub menu and press P to reveal the current setting The function may be changed by pressing the Up or Down buttons followed by the E button to return the no nc pro...

Page 24: ...AcSP prompt in the Programme Menu Code 0000 will disable the security code allowing direct access to the setpoints by pressing the P and Up buttons simultaneously New instruments are supplied with thi...

Page 25: ...installed in a poorly illuminated area The backlight is segregated from the measuring circuit and may be powered from any 18 to 30V dc supply Fig 13 Backlight power supply The brilliance of the displ...

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