User`s guide

Operation Theorem • 49
4.3 The Limit Switch Interface and I/O Status
In this section, the following I/O signals’ operations are described.
• ±SD: Ramping Down sensor
• ±EL: End-limit sensor
• ORG: Origin position
• SVON and RDY
I/O status readback
In any operation mode, if an ±EL signal is active during moving condition, it
will cause PCI-8134 to stop output pulses automatically. If an SD signal is
active during moving condition, it will cause PCI-8134 to decelerate.
4.3.1 SD
The ramping-down signals are used to slow-down the control output signals
(OUT and DIR) when it is active. The signals are very useful to protect the
mechanism moving under high speed toward the mechanism limit. PSD
indicates ramping-sown signal in plus (+) direction and MSD indicates
ramping-down signal in minus (-) direction.
During varied speed operation in the home return mode or continuous
operation mode, the ramping-down signal in the moving direction lets the
output control signals (OUT and DIR) ramp down to the pre-setting starting
velocity.
The ramping-down function can be enable or disable by software function:
set_sd_logic(). The input logic polarity, level operation mode, or latched
input mode can also be set by this function. The signals status can be
monitored by get_io_status().
4.3.2 EL
The end-limit signals are used to stop the control output signals (OUT and
DIR) when the end-limit is active. PEL signal indicates end-limit in positive
(plus) direction. MEL signal indicates end-limit in negative (minus) direction.
When the output pulse signals (OUT and DIR) are toward positive direction,
the pulse train will be immediately stopped when the PEL signal is inserted,
while the MEL signal is meaningless in this case, and vise versa. When the
PEL is inserted and the output pulse is fully stop, only the negative (minus)
direction output pulse can be generated for moving the motor to negative
(minus) direction.
The end-limit signals can be used to generate the IRQ by setting the bit 0 of
INT. factor in software function: set_int_factor().