6
5.3.8. Look-up Table Programming (F = 3..30)
If the value of set-up parameter
F
is selected equal to or
greater than 3, a sub-menu
LIn
is invoked. Through this
sub-menu all the required look-up table values can be
entered, except the first and last pairs of table values (re-
spectively corresponding to
MA
and
ME
). This sub-menu
has its own entry and exit points, the latter being the last
of the value pairs to be entered. The table is stored only
when the user exits to the sub-menu prompt
LIn
, by pres-
sing
û
. If the table is not correctly entered, the display
will indicate
Err
, indicating an error condition. If this hap-
pens, it is not possible to exit this sub-menu mode until
the error is corrected.
The table entries consist of 1 to 28 pairs of values. Valu-
es
I02
through
I29
(or
u02
through
u29
) specify the
amplitude of the signal output, and the values
P02
throu-
gh
P29
are the corresponding pressure values.
Entering or changing table values through the instru-
ment's membrane keyboard is a tedious and error-prone
method. It should only be used as a stopgap method
when a PC and/or the PC Interface Module is not availa-
ble.
The table is accepted as correct if each output value is
larger than its preceding value. Pressure values can be
steadily increasing or steadily decreasing. However, a
transition from falling to rising pressure values is not per-
mitted; nor are pressure values allowed to turn back alo-
ng the same curve.
5.3.9. Limit Setting
The two limit switching outputs
(relay contacts or
solid-state switches) are each configured by four set-up
parameters:
Switching output 1 is configured by parameters
R1A,
R1E, R1D
and
R1F
.
Switching output 2 is configured by parameters
R2A,
R2E, R2D
and
R2F
.
The turn-on and turn-off points of switching output 1 are
defined respectively by parameters
R1A
and
R1E
. The
values for these are set in the currently valid unit of mea-
surement (indicated by the lighted symbol to the right of
the digital display).
The two parameters
R1A
and
R1E
together determine the
logic of switching output 1:
If
R1A
is smaller than
R1E
, the output turns on when the
measured value exceeds
R1E
. It turns off again only
when the measured value falls below
R1A
(hysteresis
function).
If
R1A
and
R1E
have the same value, there is no hystere-
sis: the switching output turns on when the measured va-
lue exceeds
R1A
/
R1E
, and turns off again when the
measured value falls below
R1A
/
R1E
.
If
R1A
is larger than
R1E
, the switching output turns on
when the measured value falls between
R1A
and
R1E
:
i.e., when
R1E
< measured value <
R1A
(window limit
function).
Both parameters can be independently adjusted over the
full measuring range.
If the unit of measurement is changed, the switching
points are changed accordingly. In this event, rounding
error can cause a deviation in the least significant (right-
most) digit.
The value of the set-up parameter
R1D
determines the
delay time for switching output 1, after the measured va-
lue reaches the switching point. The delay value can be
selected in the range 0.0 to 100.0 secs. This value app-
lies equally to turn on and turn off.
The set-up parameter
R1F
determines the action of the
switching output. If
R1F
= 1, the switching output acts as
normally open (NO) contacts. If
R1F
= 2, it acts as nor-
mally closed (NC) contacts.
5.3.10.Password
The last set-up parameter allows a password to be en-
tered. A password value of 001 to 999 can be selected.
A value of 000 disables the password function.
If a password was set previously the digital display indi-
cates
PAS
after
Esc
is displayed and
û
is pressed. The
password is then entered, by pressing
û
and then
þ
,
ÿ
. Only then will the set-up menu options be accessible.
If an incorrect password is entered, the display jumps
back to beginning of the menu (i.e.,
Esc
).
New Functions! (as of April 2008)
5.3.11.
D0
– Display options
This parameter allows smoothing the displayed values in
cases where they are frequently deviating. The filter
function is similar to the
dAM
function, but acts only upon
the display, having no impact on the output signal. Addi-
tionally the display can be turned off partially (
D0
= -1,
only the setpoint LEDs are driven) or completely
(
D0
= -2).
5.3.12.
res
– Reset to default values
This function will reset all parameters to default when ac-
tivated. Default values can be defined only by using the
PC interface.
5.3.13.
MAF, MEF, dPF
– Free Unit
If the device is configured to have a free third unit (sym-
bol:
) then the display can be scaled as desired by
using these three parameters.
The measuring range as defined by parameters
MA
and
ME
is rescaled to
MAF
and
MEF
. If the table function (
F
)
is enabled, table values will be taken into account too.
The
dPF
value controls the position of the decimal point.
Contact: EK Engineering (India)
Web: www.ekeindia.com
Email: [email protected]
