
2408
i Indicator Engineering Manual
4.6.9
DC input Module
The DC Input module can only be fitted in slot 3. The following parameters appear:-
Module Parameters
Option
Meaning
Customer settings
3B
id
Identity of
module
dC.iP
DC input
Read only
Func
Function
nonE
No function. Input used for monitoring and alarm only
rSP
Remote setpoint input. When selected this becomes the setpoint for deviation alarms.
In
<
FuLL
>
access level, set Remote SP Enable,
<
L-r
>
=
<
rmt
>
(Remote SP selected)
Hi
Process Value = the highest of Input 1 and input 2 is displayed in normal operation. In
normal operation the display cannot be switched between ‘front’ and ‘back’ views. The
reading shows the highest or lowest value only.
Lo
Process Value = the lowest of Input 1 and input 2 is displayed in normal operation. In
normal operation the display cannot be switched between ‘front’ and ‘back’ views. The
reading shows the highest or lowest value only.
Ftn
Derived value. Process Value = (
<
F.1
>
x Input 1) + (
<
F.2
>
x input 2), where
<
F.1
>
and
<
F.2
>
are scalars found in the
<
ip
>
list in Full Access level. Refer to section 3.3.4. for an
example of differential measurement.
SEL
Select input 1 or input 2 via comms, a digital input, or in the Operator
<
ip
>
list. If a
digital input is configured use the parameter
<
PV.SL
>
. If the input is selected through
the Operator list in Full Access use the parameter
<
PV.iP
>
tran
Transition region between
<
iP.1
>
and
<
iP.2
>
, set by
<
Lo.IP
>
and
<
Hi.IP
>
in
Operator Level. See example 4.6.7.1.
If
<
Func
>
=
<
nonE
no further parameters are shown.
When
<
Func
>
≠
<
nonE
>
, input 2 parameters are shown in the Input List in Full access level
The parameters that follow are the same as those in the
<
iP
>
configuration list plus
<
HiLn
>
- the high impedance input
option
inPt
Refer to
<
iP
>
list section 4.5.2. plus the following parameter
Customer settings
HiIn
0 to 2volt high impedance input
CJC
Refer to
<
iP
>
list
Imp
InP.L
ImP.H
VAL.L
VAL.H
tYPe
Type of
calibration
off
Off
Shnt
Shunt
Ld.C
Load Cell
CmP
Comparison
man
Manual
bAnd
Settling
band.
0-
99.99
(Default
0.5
)
The indicator automatically determines when the input has become
stable by continuous sampling. When the average value between
two consecutive samples is within the settling band the indicator will
then allow calibration to take place. If readings are not stable within
this period the indicator will abort the calibration
The DC input module has a single input so the above parameters are shown under list
<
3A
>
only
4.6.9.1
Example: Input 1 and Input 2 are Configured for Transition
An example of the use for this could be the measurement of temperature over a wide range. The lower
temperatures may be measured by a base metal thermocouple connected to Input 1 and higher temperatures
may be measured by a pyrometer or precious metal thermocouple connected to input 2. The reason for such a
combination is to provide the most accurate readings over the full temperature range where the thermocouple
cannot be used at high temperatures and the pyrometer is too insensitive at low temperatures to provide an
accurate reading.
The thermocouple may be withdrawn, to prevent damage to it, using a high alarm set around the upper limit of
the thermocouple.
Figure 4-8: Input 1/Input 2 Transition
Hi.iP
Lo..iP
PV = Input 1
↓
PV = Input 2
↑
During the transition stage the display
reads a combination of Input 1 and input 2.
If
<
Hi.iP
>
=
<
Lo.iP
>
the displayed
reading will switch from input 1 to input 2
Event set at the upper limit of the thermocouple
on input 1 to signal withdrawal.
Part Number HA027240 Issue 5.0 Feb 2015
53