Fuji Electric ALPHA7, User Manual

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CHAPTER 2 WIRING
2-38
Description of I/O Signals
2
(9) A travel occurs first at the homing speed by the reverse traveling unit amount for homing.
Thereafter the motion (1) to (5) described above is executed.

Reference signal for shift operation (PA2_11)
In regular cases, a travel occurs by the home position shift unit amount in reference to the
encoder Z-phase signal. Stoppage is caused at an accuracy of a single encoder pulse. If the
Z-phase is not used positively due to a reduction ratio of 2 or similar, the home position LS can
be made the standard.
If the moving range is extremely narrow to install a home position LS signal, the +OT and -OT
signals can be referred as the standard.
If a quick response sensor is used instead of the Z-phase of the encoder, the interrupt input
signal can be applied.

Home position LS signal edge selection (PA2_13)
After the trailing edge of the LS is detected, the Z-phase signal after the home position LS is
detected.

Deceleration operation for creep speed (PA2_15)
Controlled stop is caused during homing upon detection of the home position LS (or reference
signal for shift operation), followed by reverse rotation until the point before the home position LS
is reached, and then homing is performed again at the creep speed.
The home position LS creep speed becomes the same despite the homing speed setting.

Interruption of homing motion
Forced stop (sequence input signal) can interrupt the homing motion.
Positioning cancel (sequence input signal) can interrupt the homing motion.

Interruption of homing motion
While a travel in the opposite direction automatically occurs upon detection of positive over-travel
[+OT] or negative over-travel [-OT], stoppage is caused in the following cases. In every case, the
homing completion signal will not be turned on.

Reverse rotation after a +OT signal, followed by a -OT signal without detecting a home position
LS (reference signal)

Detection of an over-travel signal in the opposite direction to the traveling direction

Detection of an over-travel signal during travel of the home position shift traveling amount