btsr IS3F-485, Operating Manual

Operation 

SMART KNIT 

- 3.7 - 

Settings that affect the sensor detection features 

The 

IS3

 sensors do not simply detect the presence of the yarn, but they work as 

true micro-computers. They provide a digital signal output, which reflects the 
condition of the yarn within the detection area: 

! 

Normal yarn running condition 

! 

Yarn missing or broken condition 

The functioning of the sensor is based on the principle of image variation related to 
the shape of the yarn, detected by the small “camera”, which is implemented inside 
the sensor. Such a variation of image 

normally

 occurs only if the yarn is in actual 

movement inside the detection area, i.e. only if the yarn is running.  
Nevertheless, in certain cases, there may be some variation of image even though 
the yarn is not running normally, this is the case of a broken yarn oscillating inside 
the detection area. 
Finally there are other factors that can affect the detection activity of the sensors, 
like the size and type of yarn 

(silk, wool, acrylic, Lycra®, single filament nylon)

, 

as the variation of the image depends on these factors as well. 
That’s why the microcomputer embedded in the sensor, processes the images 
provided by the “camera” by means of the sensor memory, which takes into 
account also these other influencing factors. 
The variables of this program are represented by the settings connected to the type 
of yarn used and to the specific application. 

! 

Non-control time 

(D_CNTR)

! 

Signaling tolerance for broken yarn

 (BROKE)

! 

Signaling tolerance for uncut yarn 

(UNCUT)

! 

Sensitivity 

(SENS)

! 

Reaction Time 

(DELAY)

! 

Start Frequency 

(F_START)

! 

Stop Frequency 

(F_STOP)

Non-control time 

(D_CNTR) 

This parameter allows you to delay the beginning of the actual control process 
after the activation of SLOW EXT and FAST EXT inputs. It can be programmed 
to a value ranging between 

100

 ms and 

20 

s. 

Signaling tolerance for broken yarn 

(BROKE) 

This parameter allows you to establish the minimum duration of “broken or 
missing yarn” anomaly, to signal the 

(BROKE)

 condition. Such duration is tightly 

related to the actual machine operating speed. It can be programmed to a value 
ranging between 

10

 ms and 

1000 

ms with steps of 

10

 ms and between 

1000

 ms and 

16000

 ms with steps of 

100

 ms, or it can be disabled 

(OFF)

. 

Signaling tolerance for uncut yarn 

(UNCUT) 

This parameter allows you to establish the minimum duration of “uncut yarn” 
anomaly, to signal the 

(UNCUT)

 condition. Such duration is tightly related to the 

actual machine operating speed. It can be programmed to a value ranging between 

10

 ms and 

1000 

ms with steps of 

10

 ms and between 

1000

 ms and 

16000

 ms with 

steps of 

100

 ms, or it can be disabled 

(OFF)

. 

Sensitivity 

(SENS)

The SENS parameter allows the control of the sensor sensitivity level, depending 
on the article to be processed. 
It can be programmed to a value ranging between 

1

 and 

10

. The default value is 

4

.