Hardware Stroke Limit Function - Mitsubishi Electric MELSEC iQ-F Series FX5 User Manual

Hardware stroke limit function

In Hardware stroke limit function, limit switches are set at the upper/lower limits of the physical movement range, and the
control is stopped (by deceleration stop) by the input of a signal from the limit switch.
This function prevents the machine from being damaged by stopping the operation before the workpiece reaches the upper or
lower limit of the physical movement range.
Hardware stroke limit switches are normally installed inside the stroke limit or stroke end on the drive unit side, and the control
is stopped before the stroke limit or stoke end on the drive unit side is reached.
Precautions
When the hardware stroke limit is required to be wired, ensure to wire it in the negative logic using a normally closed contact.
If it is set in the positive logic using a normally open contact, the operation cannot be stopped and a collision occurs when a
failure such as a disconnection occurs, resulting in the damage of the machine.
Control details
The following figure shows the operation of the hardware stroke limit function.
Lower limit
Mechanical stopper
Drive unit
stroke limit
Control range of the positioning module
Direction of
Starting Starting
movement
Decelerates to Decelerates to
a stop after the lower a stop after the upper
limit switch detection limit switch detection
Lower limit switch
Upper limit
Direction of
movement
Positioning
Upper limit switch
module
12 CONTROL SUB FUNCTION
Mechanical stopper
Drive unit
stroke limit
Drive unit
12.4 Function to Limit Control
12
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