ABB 691HT Operating Instructions Manual page 42

T R I M M I NG A N D S E T U P
SNSR 4 - 20 LOOP RERAN
TR I M TR I M TEST
L a s t t r i m : f a c t o r y
S n s r : T / C T y p e J N B S
U S E R F A C
T O R Y
N E W T R I M : U S E R
L A S T T R I M V A L U S E D
LoV a l = 0
H iV a l = 1 4 . 0 0 0
Lo V a l = 0
H i V a l = 1 4 . 0 0 0
L O W H I G H D I S P
T R I M T R I M L I M I T
L R L = - 7 . 4 0 2
U R L = 4 2 . 2 8 3
A p p l y a L o V a l
l o w e r t h a n H i V a l
E n t e r a p p l i e d L o V a l
[ - 5 . 0 1 5 ] m V
< - -- - - > C L R
- 42 -
Use of the Green Keys - TRIM - Sensor Trimming - S N S R T R I M
- ( for KST temperature transmitters )
Starting from the top display press the F1 key ( SNSR TRIM ) a warning
message is displayed:
G I NG
"WARNING - Control loop should be in manual " and the label
PROCEED for the key F4.
Pressing F4 to proceed the following display appears, giving indication
about the type of trimming presently in use and the type of the selected
sensor. The F1 and F2 keys are respectively labelled to select the user
or the factory trim.
If you wish to change either the type of trim or the trim values press the
appropriate key.
As explained above the factory trim cannot be modified: nevertheless if
you press F2 for Factory Trim while presently in use the display gives the
indication " NEW TRIM : factory ". When you press F4 the following
message appears: " WARNING - Loop may be returned to auto -
P R O
PROCEED ". Pressing F4 to proceed you will return to the Trimming and
C E E D
Setup Main Menu.
Let now us assume that you wish to change your trim to USER. This
operation requires that a suitable reference source is connected to
the K-ST terminals as explained in the previous section. Pressing F1 the
display indicates that the new trim is now User.
m V
m V
Pressing F4 to proceed a new display gives indication about the input
values used during the last trimming operation. This indication lasts for
some seconds and is then replaced by the new display below.
m V
The same values are displayed but the function keys F1 and F2 are
m V
activated for LOW TRIM and HIGH TRIM operations while F3 gives the
opportunity to read the LOWER and UPPER RANGE LIMITS (LRL and
URL). The values are displayed accordingly to the type of sensor either
in mV or in ohms. Pressing F4 to proceed you will return to the previous
screen.
m V
m V
Press the Low Trim key and a screen prompting the user to apply the low
P R O
value is displayed. The input reference must be within the range of the
C E E D
specified sensor and displayed under DISP LIMIT. To obtain the best
results the input reference should be equal to zero, for zero based
measurement, or as close as possible to the Lower Range Value.
When the input has been applied press F4 to proceed.
P R O
CE E D
The value of the input read by the transmitter is then displayed within
square brackets : this value can differ from the value read in the reference
meter. A blinking cursor is present in the most significant digit : using the
F1, to move left, or the F2, to move right, and the numerical keypad
introduce the value read on the reference meter. When the value is
E N T R
correctly introduced press F4 to ENTER the value. If, the value is incorrect
or out of limits then an appropriate messages will be issued: see the
relevant section of this manual.