Reference Mark Selector And Limit Magnet Installation - Renishaw Vionic RTLC20/FASTRACK Installation Manual

Reference mark selector and limit magnet installation

For accuracy and ease of positioning of reference mark selector and limit magnets, the applicator tool
(A-9653-0201) should be used. The magnet should be attached to the applicator tool as shown below and
aligned with the outer edge of the FASTRACK carrier. Limit magnets can be positioned at any user‑defined
location along the FASTRACK carrier, but the reference mark selector magnet should be positioned adjacent
to the selected IN-TRAC reference mark as shown below.
As the VIONiC readhead passes the reference mark selector magnet or limit switch magnet, a force of up to
0.2 N is generated between the magnet and the concentrators on the readhead. The design of the bracket
should be sufficiently stiff so that it is able to tolerate such force without distorting. Following the clamping
instructions on the scale installation will prevent this magnetic force from disturbing the scale.
Limit trigger point
The limit output is nominally asserted when the readhead limit
switch sensor passes the limit magnet leading edge, but can
trigger up to 3 mm before that edge (see 'RTLC20/FASTRACK
carrier installation drawing' on page 4).
NOTES:
X Reference and limit magnets may creep when influenced
by magnetic materials in close proximity. In such cases,
they should be held in place using an additional fillet of
epoxy glue or similar along the outer edge of the magnet
assembly.
X The reference mark selector and limit actuator locations are
correct for the readhead installation shown.
X All limit and reference selector magnets should be aligned
with the outer edges of the FASTRACK carrier.
X External magnetic fields greater than 6mT, in the vicinity of
the readhead, may cause false activation of the limit and
reference sensors.
VIONiC RTLC20/FASTRACK installation guide
P limit
magnet
Applicator tool
(A-9653-0201)
Remove
self-adhesive
backing paper
Selected IN-TRAC
reference mark
Reference mark
selector magnet
Q limit
magnet
7