Nett FLSH
(nett value display mode)
The nett value is only seen when the remote input or
P
button is set to
tARE
. The
NEtt FLSH
function can be set to
on
or
OFF
. If set to
on
then the message
NEtt
will flash briefly approximately every 6
seconds when the operator toggles to a nett display to remind the operator that a nett value is being viewed. If
set to
OFF
then the message
NEtt
will flash briefly once only when the operator toggles to the nett value.
ACCS
(access mode)
The access mode function
ACCS
has four possible settings namely
OFF
,
EASY, NONE
and
ALL
.
If set to
OFF
the mode function has no effect on alarm relay operation. If set to
EASY
the easy alarm access
mode will be activated, see details at the beginning of this chapter preceding the
A1Lo
function. If set to
NONE
there will be no access to any functions via
FUNC
mode, entry via
CAL
mode must be made to gain
access to alarm and calibration functions. If set to
ALL
then access to all functions, including calibration
functions, can be gained via
FUNC
mode.
SPAC
(setpoint access)
Sets the access to the alarm relay set points. The following choices are available:
A1
- Allows setpoint access to alarm 1 only.
A1-2
- Allows access to alarms 1 and 2 only.
A1-3
- Allows access to alarms 1, 2 and 3 only (requires optional relays to be fitted).
A1-4
- Allows access to alarms 1, 2, 3 and 4 (requires optional relays to be fitted).
The remote input function (
R.INP
) must be set to
SP.AC
for this function to operate .
Note:
Only the
setpoints which have been given a value will be accessible e.g. if
A1Hi
is set to
OFF
then there will be no
access to the
A1Hi
function when
SPAC
is used.
Sqrt
(square root)
Selects the square root scaling to
on
or
OFF
. When set to on a square root function is applied to the
input. When set to
OFF
the calibration is a linear function. Note: It is essential that the display is rescaled,
using
CAL1
and
CAL2
or
USEREn4
and
USEREN20
, whenever the square root function is turned on or
off.
When the square root facility is used the scaled displayed value follows the square root of the
percentage of the full scale input value. The upper and lower input limits are set as normal as are the values to
be displayed at these limits. For example if, for a 4 - 20mA input, you wish to display
0
at 4mA and
1000
at
20mA the square root function will calculate as follows:
At 20mA (100%) the display will be
1000
i.e. 1
1000
x
.
At 16mA (75%) the display will be
866
i.e. 0 75
1000
.
x
.
At 12mA (50%) the display will be
707
i.e. 0 50
1000
.
x
and so on.
4 .2
Lineariser functions
The following five functions are used to set up the lineariser table. The lineariser is of the X,Y type
with space for up to 50 points to be programmed and stored. All points are stored in battery backed memory
and will be retained when power is removed. Chapter 6 contains a table in which you can make a permanent
written record of the points entered.
The X values for each point will actually be indicated as
p
(e.g.
p1, p2
etc.) since the seven
segment display cannot show an X. The
p
values are normally entered either as a percentage of full scale
input or as a direct representation of the input signal e.g. for a 4-20mA input you could either enter 4mA =
0.0
and 20mA =
100.0
or 4mA =
4.0
and 20mA =
20.0
. The value entered into the table must correspond with
the initial calibration values (
CAL1
&
CAL2
or
USEREn4
&
USEREn20
). For example if a 4-20mA input is
initially scaled to read from
0.0
to
100.0
then you cannot enter these values as
4.0
to
20.0
in the table
(without causing errors in the reading). The number of decimal points available for entering
P
values is 1
decimal place.
The Y values are indicated as
Y
(e.g.
Y1, Y2
etc.) . These
Y
values represent the display required
for the given
P
value entered. For example if
P3
=
25.0
and
Y3
=
1500
then
1500
will be displayed
whenever that input is present.
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