SMRI2
7 - Output signals
Standard counting direction
Figure 5 - Example with interpolation factor 4x
As the sensor reads the magnetic ring whilst it
turns, it detects the displacement and issues an
output signal equivalent to the one of an
incremental encoder or a linear scale. The output
signal frequency is proportional to the measuring
speed while the number of output pulses is
proportional to the mechanical displacement of the
ring.
Please consider that the “R” reference signal is
provided once per revolution of the magnetic ring
(see the section “7.1 Reference “R””).
The order code indicates the interpolation factor, if
you want to know the number of edges per
revolution (intended after multiplying by 4),
multiply the interpolation factor by the number of
magnetic poles in the magnetic ring.
The number of edges per revolution results from:
interpolation * number of ring poles
EXAMPLE
SMRI2-L-1-
32
-N-L2-J: interpolation = 32;
MRI/114-
182
-2-100: number of poles = 182.
Hence:
32 * 182 = 5,824 edges per revolution
Encoder PPR result from the following calculation:
Encoder PPR =
edges/rev.
=
5,824
= 1,456 PPR
4
4
NOTE
The
standard counting direction
(the
channel A leads the channel B) is to be
intended with ring rotating as indicated
by the arrow in Figure 2.
7.1 Reference “R”
Optional “R” reference signal is provided once per
revolution of the magnetic ring (see -R- order code;
with -N- order code the Reference signal is not
provided). It provides a datum position for use at
power-up or following a loss of power. When the
sensor detects the Reference mark, the R led lights
up green. The Reference signal has a duration of one
measuring step (90 electrical degrees ± 30°). The
Reference signal can be provided only using
magnetic rings having a 10 mm / 0.4” wide
magnetic surface. The 5 mm / 0.2” magnetic surface
rings cannot be fitted with the Reference track.
8 - Maintenance
The magnetic measurement system does not need
any particular maintenance; please always consider
it is a delicate electronic equipment and therefore it
must be handled with care. From time to time we
recommend the following operations:
•
Check the mounting tolerances between the
sensor and the magnetic ring are always met
MAN SMRI2 I_E 1.3.odt
13
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