Balluff BML-S1F Series, User Manual, Page: 34 / 130

8
3
Construction and function (continued)
3.1.2 Positioning
BML-S1F1… (lengthwise direction)
Right
Left
End of magnetic tape Start of magnetic tape
Rear
Fr
ont
Reference point
BML-S1F2… (crosswise direction)
Reference point
End of magnetic tape Start of magnetic tape
Rear Front
Right
Left
Incremental sensor
Reference sensor
Fig. 3-4: Positioning of the two BML types BML-S1F1… and
BML-S1F2…
3.2 Function
The BML is a magnetically coded, non-contact,
incremental position measuring system consisting of a
sensor head and magnetic tape. The sensor head and
magnetic tape are mounted on the machine. The magnetic
tape contains alternating north and south poles.
The incremental sensor in the sensor head measures the
magnetic alternating field. Moving without any contact over
the magnetic tape, the sensor senses the magnetic
periods, allowing the controller to detect the travel range.
– To function correctly, the bottom of the
sensor head must always be above the
magnetic tape (see Distances and tolerances
on page 10).
– For a complete technical description and
assembly instructions for magnetic tapes,
please see the magnetic tape user’s guide at
www.balluff.com .
The system is available with or without a reference point
function. In a system with a reference point function, the
reference position is integrated in the magnetic tape and
the function is implemented via magnetic sampling.
Not all variants cover the illustrated functions
and deviations from the illustrations shown may
occur.
3.2.1 Sensor head and magnetic tape
The magnetic tape is not included in the scope
of delivery and must be ordered separately.
When selecting the magnetic tape, make sure
the magnetic tape and sensor head are
compatible. This particularly applies to the
following factors:
– Pole width (1 or 2 mm), see below
– Reference points (none, one, two or more
(fixed periodic)), see section 3.3
Magnetic tape
Pole width
Sensor head
BML-S1F_-_ _ _ _-M_ _0-…
Pole width Reference signal
3 = 1 mm 0 = No reference signal
5 = 2 mm 1 = With single, double, or fixed
periodic reference signal
(not with 2 mm pole width)
2 = Pole-periodic reference
signal (only with
BML-S1F…-Q61… (digital),
not with 2 mm pole width)
BML-S1F_-A/Q _ _ _ -M_ _ 0- _ 0-…
Incremental Magnetic Linear Encoder
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