CONTREX M-Traverse - Manual (Page 92)

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HOME SET
Home Set is one of two ways in which you can establish “Home” (Home Seek is the
other way). When the Home Set input is closed, it sets the current position of the
Follower mechanism as “Home”. Home Set will establish “Home” at any arbitrary
position that you choose. You can use the Jog input to position the Follower
mechanism or you can position it manually.
Home Set enables the Drive Enable logic output, which allows the Follower mechanism
to hold its position at “Home” despite any outside force (such as gravity). The Home
Set is a momentary input that is edge triggered and is activated through the Home Set
input (J3, pin 14,16).
NOTE: “Home” must be established before the Follower mode can be used. “Home”
is identified by a Follower position of zero. In the Follower mode, “Home” is
the position from which the profile traverses in the Forward direction.
HOME SEEK
Home Seek also establishes “Home”. Home Seek finds and sets “Home” by locating
the Home Sync Sensor. When the Home Seek input is closed, the Follower
mechanism makes a profiled move at jog speed, until it aligns with the Home Sync
sensor, which then becomes “Home”.
Home Seek enables the Drive Enable logic output, which allows the Follower
mechanism to hold its position at “Home” despite any outside force (such as gravity).
Home Seek is a momentary input that is edge triggered and is activated through the
Home Seek input (J4, pin 1, 2). Home Seek is internally latched and does not need to
be maintained by an operator device.
NOTE: “Home” must be established before the Follower mode can be used. “Home”
is identified by a Follower position of zero. In the Follower mode, “Home” is
the position from which the profile traverses in the Forward direction.
Home Seek will always begin to move the Follower mechanism in the reverse direction
(towards the reverse limit). When Home Seek locates the Home Sync sensor, it
ramps down at the Accel/Decel rate (CP-60) to zero. This causes the Follower
mechanism to overshoot the Home Sync sensor and the M–Traverse compensates with
a triangulated forward Accel/Decel move that aligns the Follower mechanism with the
Home Sync sensor. There are a variety of profile possibilities, since Home Seek can
find home from any position on the traverse length. The following examples will
illustrate four possible Home Seek profiles.