Conf - Change I/O - Root Xfer Function Option; Conf - Change I/O - Sqr(X) Cut Linear Option - ABB 691HT Operating Instructions Manual

ROOT XFER FUNCTION :
Undefined
N E X T L A S T CHNG
O P T N O P T N
W A R N I N G - Control l o o p
s h o u l d be i n m a n u a l
ROOT XFER FUNCTION :
[ Undefined
N E X T L A S T
O P T N O P T N
ROOT XFER FUNCTION :
[ Linear 20 % output ]
N E X T L A S T CHNG
O P T N O P T N
W A R N I N G - l o o p m a y be
r e t u r n e d to a u t o
SQR(x) CUT LINEAR :
10.0%
NEXT LAST CHNG
OPTN OPTN
W A R N I N G - Control l o o p
s h o u l d be i n m a n u a l
SQR(x) CUT LINEAR :
[ 12.0 ]%
<-- --> CLR
- 24 -

CONF - Change I/O - ROOT XFER FUNCTION option

(600T and Deltapi K Pressure Transmitter)
When the Square Root option is active and SQR (x) selected, two output
modes are available in the 600T transmitters:
a) when the input varies from 0% to 4% the output varies linearly from 0%
to 20%. At input's values greater than 4% the output follows the applied
transfer function .
b) when the input varies from 0% to 4% the output varies linearly from 0%
to 4% too. At input's values greater than 4% the output jumps to 20%
P R O
and then follows the applied transfer function. To avoid transition
C E E D
problems a hysteresis of 4% of the output signal is applied when the
output decreases below the 20%.
The option a) is the default option.
]
From the Configuration main menu press the F1 ( CHNG-I/O ) and then
E N T R
F1 ( NEXT-OPTN ) until the Root Xfer Function display is present.To
change the Root Transfer function press CHNG (F3): the warning
message will be displayed.
Press PROCEED, use the F1 (NEXT OPTN) or F2 (LAST OPTN) key
select one of the required function:
[ Lin. 1:1 20% oput ] or [ Linear 20% output ]
and then press the ENTER key. The display returns to the previous one
but with the required option. Press NEXT OPTN if you want to stay in the
Change Output option or ESCAPE to return to the Configuration main
P R O
menu. In this case a warning message is displayed to warn to change the
C E E D
loop in Auto, if necessary.

CONF - Change I/O - SQR(x) CUT LINEAR option

(600T EN Pressure Transmitter)
When the output transfer function is set to Square root, the SQR(x) CUT
LINEAR option can be used to configure to Square root function.
The user is asked to verify that the control loop is in manual.
With F4 (PROCEED) a screen displays the current CUT LINEAR value:
12.0% in the esample.
Acceptable values are between 10% and 20%.
P R O
C E E D
As already explained in the 600T EN Series Instruction Manual, this value
represents the percentage of output where it is used the Square root
function. Before this percentage the output varies linearly.
Refer to 600T EN Series Instruction Manual for more information.
ENTR
Press ENTR to accept the new value.