Operation Manual

2.8.1 Counter for Control of the Underthread Reserve
The decrementer, which can be preset in program
P41,
monitors the
underthread reserve.
It is decreased by the value 1 after every 10 stitches.
The height of the initial value to be selected depends
–
on the thickness of the underthread used
–
on the amount of thread wound onto the bobbin.
Example:
With an 100/2 underthread 18 000 stitches can be sewn with one
bobbin filling.
The initial value to be set thus results from:
18 000 stitches : 10 = 1 800 stitches
The exact initial value to be set can best be arrived at during operation:
–
Insert a full bobbin.
–
Preset the initial value in program
P41
.
See Short Description Microcontrol.
ATTENTION !
The underthread monitoring through the counter is turned off by
setting the initial value to
0000
.
–
Start the sewing sequence.
–
If, when the counter reaches
0000,
there is still a large quantity of
thread remaining on the the bobbin, then the set initial value can
be increased.
–
When the counter reaches
0000
the already begun seam is still
securely sewn to the end.
The display shows the symbol (bobbin empty).
The sewing unit can not be started.
–
Turn the main switch off.
Caution Risk of Injury !
Turn the main switch off.
Change the bobbin only with the sewing unit turned off.
In order to start a new sewing sequence after a bobbin change, it is
essential that the main switch be turned off.
–
Change the bobbin.
–
Turn the main switch on.
When the unit is turned on the initial value of the counter is
automatically loaded.
Display of the counter for the underthread reserve
The monitoring of the underthread counter is turned on or off by
program 44.
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