- 35 -
Use of the Green Keys - TRIM - Loop Test Option
The scope of this procedure is to test the transmitter output at fixed
values, 4 or 20 mA, or at a value selected by the user, and so to test the
integrity of the transmission loop and the operation of receiving instruments
like controllers, recorders, etc. This option is useful during the plant
commissioning when a transmitter fixed value is required.
Use the LOOP TEST function key to select this procedure from the
TRIMMING and SETUP submenu. The screen will display the warning
message:
"WARNING - Control loop should be in manual".
Press the PROCEED key to acknowledge the message and continue.
Use F1 or F2 to select 4mA or 20 mA output. If you select F3 (OTHER)
then the following display appears allowing any value from 3.875 to 21 mA
to be entered. In this case the last set value is displayed within square
brackets with the first figure blinking: using the F1 and F2 and the
numerical keypad a new value in the range 3.875 to 21 mA can be
introduced.
The Hand Held Communicator is now ready to set the transmitter to the
required current (12.5 in the example): press F4 to PROCEED.
The blinking T appears in the upper right corner of the display signalling
that the communication is on course and after some seconds the next
display appears with the output set to the required value.
At this time, the user may verify the current by reading an appropriate
meter or can check the functionality of the instruments connected to the
control loop.
Pressing F4 (END) returns to the Loop Test main menu enabling the
execution of the procedure with a different setting, whereas pressing
ESCAPE forces the exit from the procedure: in this case the next display
will appear notifying the user of the restoration of the original output.
After some seconds a new display warns to return the control loop in auto.
Pressing F4 to PROCEED the Communicator returns to the Trimming
Main Menu.
S e l e c t o u t p u t
[ 1 2 . 5 0 0 ] mA
< - - - - - - > C L R E N T R
A b o u t t o s e t X m t r T
o u t p u t to 12.5 m A
P R O
C E E D
L o o p t e s t : X m t r
o u t p u t i s 12.5 m A
E N D
T R I M M I NG A N D S E T U P
SNSR 4 - 20 LOOP CALI
TR I M TR I M TEST BRA
L O O P T E S T - C H O O S E
CURRENT OUTPUT LEVEL
4 mA 20mA OTHER
R e t u r n i n g X m t r T
t o o r i g i n a l o u t p u t
W A R N I N G - loop may be
returned to auto
PRO
CEED
