AMALGAMATED INSTRUMENT RM4-IV, Operation And Instruction Manual

Page: 29 / 49

5.33 Square root mode
Display:
SQrt
Range:
on
or
OFF
Default Value:
OFF
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. 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.
Note: It is essential that the display is rescaled, using
CAL1
and
CAL2
or
USER En4
and
USER
En20
, whenever the square root function is turned on or off. The
CAL OFSt
function cannot
be used when the
SQrt
function is set to
on
. Example:
For a 4–20mA input if 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.
At 16mA (75%) the display will be
866
i.e.
√
0 . 75
×
1000.
At 12mA (50%) the display will be
707
i.e.
√
0 . 5
×
1000 and so on.
5.34 Alarm relay operation mode
Display:
A1, A2
etc.
Range:
LiuE, tARE, P.HLd, d.HLd, Hi, Lo
or
dISP
Default Value:
LiuE
Alarm relay operation mode for relays 1, 2 etc. The following choices are available for alarm
operation mode:
LiuE
- live input mode. The alarm relay operation will always follow the electrical input at
that time irrespective of the 7 segment display value. e.g. assume the remote input is set
to
tARE
and
A1Hi
is set to
100
. If the instrument is tared at a display reading of
30
then the alarm will now activate at a display reading of
70
. Note that the
LIUE
mode
does not follow the electrical input if a remote input or
P
button
ZERO
operation has been
undertaken. This is due to the fact that the
ZERO
operation shifts the display calibration.
tARE
- tare mode. The alarm relay operation will follow the tare function. e.g. in the example
above (
LiuE
) if
A1
is set to
tARE
then the alarm would activate at a display reading of
100
(the setpoint value) rather than
70
.
P.HLd
- peak hold mode. When
P.HLd
is selected and the remote input is set to peak hold
(
P.HLD
) then once the peak display goes above any alarm high setpoint the alarm relay will
activate and will not de-activate until the peak hold is released and the display value falls
below the setpoint value.
d.HLd
- display hold mode. When
d.HLd
is selected and the remote input is set to display hold
(
d.HLd
) then the alarm relay will be held in its present state (activated or de-activated)
until the display hold is released and the display is free to change.
Hi
- peak (max.) memory mode. When
Hi
is selected and the remote input is set to peak
memory (
Hi
) then the alarm will be activated if the peak memory value is above the high
setpoint value. The alarm will not de-activate until the memory is reset.
RM4IVMAN-2.1-0 29 of 49