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Soft-start, Remote setpoint, Control mode – NOVUS Controller N1100 User Manual

Page 3: Pid automatic mode

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N1100 Controller

NOVUS AUTOMATION

3/11

PROMPT

TYPE

ACTION

Off

Disabled

Output is not used as alarm.

Ierr

Sensor Break

(input Error)

Activated when the input signal of PV is

interrupted, out of the range limits or Pt100

in short-circuit.

Rs

Event

(ramp and Soak)

Can be activated at a specific segment of

program.

rfail

-

Reserved

Lo

Minimum value

(Low)

SPAn

PV

Ki

Maximum value

(High)

SPAn

PV

Difl

Minimum

Differential

(differential

Low)

Positive SPAn Negative SPAn

SV

PV

SV - SPAn

SV

PV

SV - SPAn

Difk

Maximum

Differential

(differential

High)

SV

PV

SV + SPAn

SV

PV

SV + SPAn

Positive SPAn

Ngative SPAn

Dif

Differential

(differential)

SV

PV

SV + SPAn

SV - SPAn

SV

PV

SV - SPAn

SV + SPAn

Positive SPAn

Nagative SPAn

Table 3 – Alarm functions

Where SPAn refers to Setpoints of Alarm “SPA1”, “SPA2”, “SPA3”

and “SPA4”.

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

• Continuous (normal mode).

• One pulse with defined duration;

• Delayed activation;
• Repetitive pulses;

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, A1t2, A2t1 and A2t2.

OPERATION

T 1

T 2

ACTION

Normal

operation

0

0

Alarm Event

Alarm

Output

Activation for

a defined time

1 s to

6500 s

0

Alarm Event

Alarm

Output

T1

Activation with

delay

0

1 s to

6500 s

Alarm Event

Alarm

Output

T2

Intermittent

activation

1 s to

6500 s

1 s to

6500 s

Alarm Event

Alarm

Output

T1

T2

T1

Table 4 - Temporization Functions for the Alarms

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 be enabled only after the occurrence of a non-alarm

condition followed by a new occurrence for the alarm.
The initial blocking is useful, for instance, when one of the alarms is

configured as a minimum value alarm, causing the activation of the

alarm soon upon the process start-up, an occurrence that may be

undesirable.
The initial blocking is disabled for the sensor break alarm function.

SQUARE ROOT EXTRACTION
When the input type is configured as SQRT the controller assumes

the input as a 4-20 mA while extracting the square root of the applied

input signal.

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

for retransmitting the PV 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 scalable, with the output range defined by

the values programmed in the parameters “SPLL” and “SPkL”.
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).

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 4c.

CONTROL MODE
The controller can operate in two different manners: Automatic mode

or Manual mode.
The parameter “

avto

” defines the control mode to be adopted.

In Automatic mode the controller defines the amount of power to be

applied on the process.
In Manual mode the user himself defines this amount of power. The

user can then adjust the MV percentage while displaying PV/MV.

PID AUTOMATIC MODE
For the Automatic mode, there are two different strategies of control:

PID automatic control and ON/OFF automatic control.
PID control has its action based on a control algorithm that takes into

account the deviation of PV with respect to SP, the rate of change of

PV and the steady state error. These parameters are particular to a

system and can be obtained automatically by the controller’s Auto

Tune feature (Atvn parameter).
On the other hand, the ON/OFF control (obtained when Pb=0)

operates with 0 % or 100 % of power, when PV deviates from SP.
The determination of parameters Pb, Ir and Dt is described in

the item DETERMINATION OF PID PARAMETERS of this manual.