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Alarm timer functions, Alarm initial blocking, Square root extraction – NOVUS Controller N3000 User Manual

Page 3: Analog retransmission of pv and sp, Remote setpoint, Lbd - loop break detection alarm, Key functions, Extra 24 vdc power supply – auxiliar p.s, Ierr, Difl

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Controller N3000

NOVUS AUTOMATION

3/11

The alarm functions are described in Table 3.

TYPE

PROMPT

ACTION

Disabled

off

No active alarm. This output can be used as a

digital output to be set by the serial

communication.

Sensor Break

(input Error)

ierr

Alarm will be ON if PV sensor breaks, input

signal is out of range or Pt100 is shorted.

Event Alarm

(ramp and

Soak)

rs

Can be activated at a specific segment of ramp

and soak program.

Low Alarm

lo

SPAn

PV

High Alarm

ki

SPAn

PV

LOW

Differential

difl

SV

PV

SV - SPAn

positive SPAn

SV

PV

SV - SPAn

negative SPAn

HIGH

Differential

difk

SV

PV

SV + SPAn

positive SPAn

SV+SPAn

PV

SV

negative SPAn

Differential

dif

SV

PV

SV + SPAn

SV - SPAn

positive SPAn

SV

PV

SV - SPAn

SV + SPAn

negative SPAn

Table 3 - Alarm functions

ALARM TIMER FUNCTIONS
The controller alarms can be configured to perform 4 timer modes:

• Continuous (normal mode).
• One pulse with defined duration;
• Delayed activation;

The illustrations in Table 4 show the behavior of the alarm output for

various combinations of times T1 and T2. The timer functions can be

configured in parameters A1t1, A2t1, A3t1, A4t1, A1t2, A2t2,
A3t2

, A4t2.

ALARM

FUNCTION

T1

T2

ACTION

Normal

0

0

Alarm Event

Alarm

Output

Delayed

0

1 s to 6500

s

Alarm Event

Alarm

Output

T2

Pulse

1 s to 6500

s

0

Alarm Event

Alarm

Output

T1

Oscillator 1 s to 6500

s

1 s to 6500

s

Alarm Event

Alarm

Output

T1

T2

T1

Table 4 - Advanced Timer Alarm

The LEDs associated to the alarms will light when the alarm condition

is recognized, not following the actual state of the output, which may

be temporarily OFF because of the temporization.

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.

SQUARE ROOT EXTRACTION
Available when input type 19 is selected. The indicator displays the

square root of the current signal input applied to terminals 22 and 24.

ANALOG RETRANSMISSION OF PV AND SP
The analog output, when not used for control purposes, is available

for retransmitting the SV and SP values in 0-20 or 4-20 mA. This

analog output is electrically isolated from other inputs and outputs.

The analog output signal is scaleable, with the output range

determined by the values programmed in the parameters “SPLL” and

“SPkL”. To obtain a voltage output, connect a resistor shunt to the

current output terminals.
It is possible to obtain a voltage output by installing a resistor shunt

(550 Ω max.) to the current output terminals (terminals 7 and 8). The

actual resistor value depends on the desired output voltage span.

SOFT START
The soft-start feature avoids abrupt variations in the power delivered

to the load regardless of the system power demand.
This is accomplished by defining a limiting ramp for the control output.

The output is allowed to reach maximum value (100 %) only after the

time programmed in the soft-start parameter has elapsed.
The Soft-start function is generally used in processes that require slow

start-up, where the instantaneous application of 100 % of the available

power to the load may cause damages to parts of the system.
In order to disable this function, the soft-start parameter must be

configured with 0 (zero).
Note:
1- This feature is available only with PID (Proportional Band greater

than zero).
2- This feature is disabed if the parameter is set to 0 (zero)

REMOTE SETPOINT
The controller can have its Setpoint value defined by an analog,

remotely generated signal. This feature is enabled through the

channels I/O3, I/O4 or I/O5 when configured as digital inputs and

configured with the function rsp (Remote SP selection) or through

the parameter E.rsp. The remote Setpoint input accepts the signals

0-20 mA, 4-20 mA, 0-5 V and 0-10 V.
For the signals of 0-20 and 4-20 mA, a shunt resistor of 100 Ω is

required between terminals, as shown in Figure 4d.

LBD - LOOP BREAK DETECTION ALARM
The parameter defines a time interval, in minutes, within which the

PV is expect to react to a control output signal. If the PV does not

react properly within the time interval configured in lbd.t, the

controller interprets this as a control loop break and signals this

occurrence in the display.
A LBD event may be sent to any I/O channel. Simply configure the
LDB function to the desired I/O channel: the selected output will be

activated when a LDB condition is detected. When the lbd.t

parameter is programmed with 0 (zero), the LDB function is disabled.
The LDB is useful in system supervision and troubleshooting, allowing

early detection of problems in the actuator, power source or load.

KEY FUNCTIONS

Both the

key digital input can be programmed to execute

functions RVN , RSP, kPRG, PR1 shown in Table 2. The key

function is configured in parameter (fFvn).

EXTRA 24 VDC POWER SUPPLY – AUXILIAR P.S.
The controller provides a voltage power supply of 24 Vdc to excite

field transmitters with 25 mA current capacity. Available at the back

panel terminals 17 and 18.