Mitsubishi Electric MELSEC iQ-R RD75P4, User Manual

Page: 243 / 598

7 CONTROL SUB FUNCTIONS
7.4 Function to Limit Control
241
7
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.
Control details
The following figure shows the operation of the hardware stroke limit function.
WARNING
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.
RD75
Machine stopper Machine stopper
Movement
direction Movement
direction
RD75 control range
Start Start
Stroke limit
of the drive unit
Lower limit
Upper limit
Deceleration stop is carried
out with the detection
of lower limit switch. Deceleration stop is carried
out with the detection
of upper limit switch.
Lower limit switch Upper limit switch
Stroke limit
of the drive unit
Drive unit