Customized linearization, Retransmission, Alarms – NOVUS N1500FT Indicator User Manual

Page 2: Alarm functions, Alarm timer, Alarm hysteresis, Initial alarm block, Special functions, Maximum and minimum

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N1500FT Flow Indicator

NOVUS AUTOMATION

2/9

CUSTOMIZED LINEARIZATION
When the flow rate is read through a 4-20 mA input, it is possible to

apply a customized linearization composed of 30 input points and 30

output points. Whenever the reading falls between two input points, it

will be normalized to the range defined by the respective points in the

output range.
The input range considered as an input to the linearization table is

the range defined by the user in the InLL and InKL parameters (it is

not the current in mA). In case user wants to enter the values directly

in mA to convert to the desired viewing unit, parameter 1n LL must

be set as 4 (mA) and parameter 1n xl

as 20 (mA), using as many

decimal places as needed to the desired precision. It will be possible

then to enter values between 4-20 (mA) as input points for the

customized linearization.
The search for framing the value read is done while the list of input

points is incrementally declared. The search is terminated if the next

point in the list is lower than the current one. If the input value is

lower than the first value in the list of input points, linearization will

return the first output value. Similarly, if the input value is greater

than the highest value in the list of input points, linearization will

return the highest value in the output list.
IMPORTANT: At least two pairs of input-output points are required

for adequate customized linearization.

RETRANSMISSION

Flow rate retransmission can be done via 4-20 mA output and pulse

output.
The 4-20 mA output may be used regardless of the type of flow input.

To use it, just set the retransmission range to RTLL and RTKL,

associating the flow rates to 4-20 mA.
In the case of retransmission via pulse output, one must choose

between volumetric pulse output and frequency pulse output. The

former may be used regardless of the type of input, while the latter is

available only for pulse inputs.
In the volumetric mode, a pulse of configurable length is generated

every time the totalizer accumulates a preset volume. For example,

for a period of 1 second and volume of 10 liters, a 1-second pulse will

be generated for every 10 liters totalized. The counting to the output

pulse will be reset every time the user resets the totalizer or

whenever a feeding process is finished.

Note: In case the feeding process is running and the totalizer is reset

by the user, the process will remain running normally, but the output

pulse will not be synchronized with this process anymore, which can

lead to a missing pulse informed at the end of the feeding process.

As it is always reset at the end of the process, output pulse counter

will synchronize again for a new feeding process.
In the frequency mode, the pulse output will divide the input

frequency by a programmable constant whose value is equal to or

higher than 2.
IMPORTANT: Maximum output frequency has hardware limitation.

See Specifications. Check the “Specifications”.

ALARMS

The indicator’s basic version has 2 alarm outputs, with the option of

up to 4 alarms. Whenever an alarm is on, a corresponding light

signal will be displayed on the front panel.

ALARM FUNCTIONS
The alarms can be programmed to operate with four different

functions, described below. They may also be turned off.
Alarms use only the instantaneous flow rate reading. Totalization

readings cannot be used as input for alarms. The auxiliary 4-20 mA

input (when it is not being used for flow rate measurement) may be

used only as input for the open sensor alarm.
• Open Sensor – I.error
The open sensor alarm operates whenever the input sensor is badly

connected or broken. Valid only for 4-20 mA inputs.

• Minimum Value – Lo
It sets off when the reading is below the value determined by the

alarm Setpoint.
• Maximum Value – Ki
It sets off when the reading is above the value determined by the

alarm Setpoint.
• Feeder Function – FEEDER
It activates the output relay when it is started by pressing

or

via the auxiliary digital input (according to setup) and deactivates

when the reading reaches the value determined by the alarm setpoint
or when the

key or digital input is pressed/closed again,

putting the process on hold. In case of pressing the

key or

digital input more than 3 seconds, process is reset and stays waiting

to be started.
Further details in the

Feeder

section.

ALARM TIMER
The indicator allows setting up an Alarm Timer, where users can set

the alarm to go off with a delay, to go off in only one pulse or to go off

in sequential pulses.
Figures in Table 1 show these functions. There, times T1 and T2

may vary from 0 to 32000 seconds and are defined while

programming the indicator. For regular (no timers) operation of

alarms, simply set T1 and T2 to 0 (zero).
He alarm light signals will be displayed whenever there is alarm

condition, regardless of the current status of the output relay, which

may be temporarily out of power because of the timer function.

ADVANCED

FUNCTION

T1

T2

ACTION

Regular

Operation

0

0

Delay

0

1 to 32000

Pulse

1 to 32000

0

Oscillator 1 to 32000 1 to 32000

Table 1 - Alarm timer functions

ALARM HYSTERESIS
Hysteresis
defines the difference between the value measured when

the alarm is triggered and the value at which it is deactivated.

INITIAL ALARM BLOCK
The initial block option prevents the alarm from going off in case there

is alarm condition at the time the indicator is being energized. The

alarm may be triggered only after a non-alarm condition is followed by

an alarm condition. This function is not valid for alarms programmed as

Open Sensor.

SPECIAL FUNCTIONS

MAXIMUM AND MINIMUM
The flow indicator continuously records the minimum and maximum

values of instantaneous flow rate. These values can be viewed on

the first screen of the main cycle by pushing

and

,

respectively. The

key can be set to zero maximum and

minimum values.

Alarm Event

Alarm

Output

Alarm Event

Alarm

Output

T2

Alarm Event

Alarm

Output

T1

Alarm Event

Alarm

Output

T1

T2

T1

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