COMECO TI08 Bedieningshandleiding - Pagina 10

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Input Filtration

Peak filter

This filter is intended for eliminating

pulse spikes (peaks), which can appear

in the input signal, in the following way:

♦

TI08 measures the input signal value

every 120 ms (sample time).

♦

The measured values are compared

subsequently. The filter checks

the difference between the last

2 samples. If it does not exceed

Gradient value, the device accepts

the signal as normal.

♦

If the last measured value differs

from the previous one by more than

the Gradient value, the filter output

is held until the device determines

a presence of a normal signal.

It is possible only if the input signal

has not been changed with more than

the Gradient value for 4 subsequent

samples.

♦

If the device has not determined

a normal signal for 20 subsequent

samples, noiS appears on the display

(see 'Basic level').

Low-pass filter

This first-order filter acts ONLY within

a certain band around filter output value.

This has been designed to cut periodic

noises outside the communication signal

spectrum.

♦

Filter operation is defined by two

parameters:

Filter Time (defines filter time constant) and

Filter Band (defines filter active band

around filter output value).

♦

If the newly measured value differs

from the filter output by more than

Filter Band, the filter resets

with a new initial output value

(newly measured value).