BEKA BA574C - Page 18

Step 2 Enter the Programme Menu
Enter the Programme Menu by
simultaneously pressing the P and E
buttons. The transmitter will respond by
displaying 'COdE'. Press P to clear this
prompt and set the display to the
security code 1209 using the Up, Down
and P push-buttons. Pressing E will
enter the code. After a few seconds
during which all the decimal points will
be activated, the first parameter 'InPut'
will be displayed.
Step 3 Define input
With 'InPut' displayed press P which
will reveal the current transmitter sensor
type. Using the Up or Down button
scroll through the menu until
thermocouple input 'tHC' is displayed.
Step 4 Define type of thermocouple
With 'tHC' displayed press P to enter
the thermocouple sub-menu. The first
parameter 'tYPE' will be displayed,
pressing P again will give access to the
seven different types of thermocouple.
Select 'J' using the Up or Down button
and then press E to return to the
sub-menu.
Step 5 Define units of display
Using the Up or Down button select
'dEg', from the sub-menu and press P
to reveal the current units. Pressing the
Up or Down button will toggle between
o
C and
o
F. Select
o
C and press E to
return to the sub-menu.
Step 6 Resolution
Using the Up or Down button select
'rESn' from the sub-menu and press P.
Pressing the Up or Down button will
toggle between high and low resolution,
select 'Hi' and press E to return to the
sub-menu.
Step 7 Cold junction compensation
In this example only one thermocouple
is connected so cold junction
compensation is required. Using the Up
or Down button select 'CJC' from the
sub-menu and press P. The Up and
Down buttons will turn the cold junction
'On' or 'OFF'. Select 'On' and press E
to return to the sub-menu.
Step 8 Input open circuit drive
Using the Up or Down button select
'burn' from the sub-menu and press P to
reveal the current status. Select 'uP'
using the Up or Down button and press
E three times to return to the 'InPut'
prompt via the 'burn' and 'tHC' prompts.
Step 9 Calibrating the 4/20mA output
'CAL' defines the display at which the
output current is 4mA and 20mA.
Select 'CAL' from the menu using the
Up or Down push-button, and enter the
sub-menu by pushing P. The
transmitter will display a 'ZEro' prompt
requesting the display at which the
output is to be 4mA. Press P and
enter -10.0 using the Up, Down and P
buttons. Press E to return to the 'ZEro'
prompt. Select 'SPAn' from the
sub-menu and press P. Enter 240.0
which is the display at which the output
current is to be 20mA and press E
twice to return to the 'CAL' prompt.
Step 10 Return to the display mode
With the 'CAL' prompt displayed, press
E to store the conditioning and
calibration information and return to the
display mode. All the display decimal
points will be activated while the
information is being stored. This
completes the calibration of the
transmitter using the internal
references.
The following steps explain how, using the Trim
Menu, the BA574C transmitter may be calibrated
against an external reference, such as a voltage
source or temperature calibrator. Alternatively, the
complete loop including the primary element may
be calibrated by cooling and heating the
thermocouple to -10 and +240
o
C.
Step 11 Entering the Trim Menu
Enter the trim menu by simultaneously
pressing the P and Down buttons - see
Fig 7. The transmitter will respond by
displaying 'COdE' . Press P to clear
this prompt and set the display to the
security code 1209 using the Up, Down
and P push-buttons. Pressing E will
enter the code. After a few seconds
during which all the decimal points will
be activated, the first parameter 'ZEro'
will be displayed.
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