NOVUS N1500G - Manual (Page 2)

Indicator N1500G
NOVUS AUTOMATION 2/5
3.1.3. High alarm
The alarm relay will be ON whenever the measured value is above
the alarm set point.
3.1.4. Differential (Band)
For differential alarm 2 parameters must be set: Differential Alarm
Reference value (ALrEF) or alarm setpoint and Alarm Deviation
(Band).
For a positive deviation the alarm will switch on whenever the
measured value is out of the band defined as:
(ALrEF - Deviation) and (ALrEF + Deviation)
For a negative deviation the alarm will be switched on whenever the
measured value is within the band defined above.
3.1.5. Differential Low
The alarm relay will be ON whenever the measured value is below
the band defined as:
(ALrEF - Deviation)
3.1.6. Differential High
Alarm relay will be ON when the measured value is above the band
defined as:
(ALrEF + Deviation)
3.2. ALARM INITIAL BLOCKING
The initial blocking option inhibits the alarm from being recognized if
an alarm condition is present when the controller is first energized.
The alarm will actuate only after the occurrence of a non alarm
condition followed by a new occurrence for the alarm.
The initial blocking is disabled for the sensor break alarm function.
3.3. ALARM TIMER
The alarms can be programmed to have timer functions where the
user can set a delayed alarm action, just one pulse in an alarm
event, or an oscillator function with sequential pulses.
Table 3 shows these advanced functions. Times T1 and T2 can be
programmed from 0 to 6500 seconds (refer to item 8.2). Set 0 (zero)
at the T1 and T2 prompt for a normal non-timer alarm operation.
The LEDs alarm anunciators will go ON whenever there is an alarm
condition regardless of the present alarm status which may be
temporarily off because of timer action.
Advanced
Function
T1 T2 ACTION
Normal
Operation
0 0
Alarm Event
Alarm
Output
Delayed 0 1s to 6500s
Alarm Event
Alarm
Output
T2
Pulse 1s to 6500s 0
Alarm Event
Alarm
Output T1
Oscillator 1s to 6500s 1s to 6500s
Alarm Event
Alarm
Output T1 T2 T1
Table 3 - Timer Alarm Functions
4. SPECIAL FUNCTIONS
4.1. MAXIMUM AND MINIMUM
The indicator memorizes the measured maximum and minimum
values (peak and valley). These two values are shown by pressing
either the MAX or MIN key. Pressing both keys simultaneously will
clear the memory for a new peak and valley detection.
4.2. SPECIAL FUNCTION KEY AND DIGITAL INPUT
The F key and the optional digital input can execute special functions
according to the user selection.
These functions can be chosen independently to the F key or to the
digital input. Figure 10 shows how to activate the digital input. A
closed contact or a short circuit at terminals 8 and 9 is recognized as
activating the digital input.
The special functions for the F key and for the digital input are
explained as follows.
4.2.1. Hold
The hold function freezes the measured value in the display. Each
touch at the F key or closing the digital input alternates from hold to
normal mode.
Whenever the indicator is in the hold mode a “HoLd” message is
briefly displayed to show the operator that the displayed value is the
frozen value and not the present reading.
4.2.2. Peak Hold
The indicator turns automatically to Peak Hold mode whenever the F
key or the digital input are programmed for “PHoLd”
This operation mode makes the indicator display only the maximum
reading value from the time the key was pressed of the digital input
was activated.
Each activation of the F key or digital input triggers a new Peak
Hold cycle and the display resets with a new peak value.
4.2.3. Reset (clears maximum and minimum)
This function works the same way as the MAX and MIN keys pressed
simultaneously, as explained in the 5.1 section.
If this “rESEt” function is programmed, for every touch of the F key or
activation of the digital input the memory will be cleared and a new
cycle of maximum and minimum will start.
4.2.4. AL.oFF - Alarm blocking
This function allows the user to block or inhibit the alarm relays by
pressing the F key or by activating the digital input. Each touch of
the key or activation of the digital input will alternate the function from
ON to OFF and vice-versa.
If an alarm situation occurs, the respective alarm status LEDs in the
front panel will light regardless of the relay alarm blocking status.
4.2.5. Tare
This function is used to zero the display. The tare residual values is
subtracted or added to the total measured value. This function is
generally used with load cells and strain gauges and applies to linear
4-20 mA, 0-50 mV and 0-5 V inputs.
4.3. PROCESS VARIABLE RETRANSMISSION
As an option, the indicator can be supplied with an isolated 0-20 mA
or 4-20 mA analog output for Process Variable (PV) retransmission.
The PV values which define the range of the 0-20 mA or 4-20 mA
retransmission can be programmed by the user in the high and low
indication limits.
When available, this current output will be always active.
For a voltage output signal an external shunt (calibrated resistor)
should be installed at the analog output terminals.
5. INSTALLATION
5.1. PANEL ASSEMBLY
The indicator is composed of two parts: the fixing base and the front
part with main circuits. The base must be removed from the front and
fixed onto a wall by means of four designed holes as shown in figure
2.
90
266
4X 4mm
3X 12mm
Figure 2 - Mounting the indicator in the panel cut-out.
The front part is only attached to the fixing base after all electrical
wire connections are done.