Near-Point Dog Method - Mitsubishi Electric MELSEC iQ-R-RD75P4 User Manual

Near-point dog method

The following shows an operation overview of the near-point dog method, one of the OPR methods.
Operation chart
Machine OPR start
(Positioning start signal)
[Y10, Y11, Y12, Y13]
OPR request flag
Md.31
Status: b3
OPR complete flag
Md.31 Status: b4
Deviation counter clear output
Axis operation status
Md.26
Movement amount
Md.34
after near-point dog ON
Md.20 Current feed value
Md.21 Machine feed value
(1) The machine OPR is started.
(The machine starts accelerating according to the setting of [Pr.51] OPR acceleration time selection in the direction specified in [Pr.44] OPR direction, and
moves at the speed set in [Pr.46] OPR speed when the acceleration is completed.)
(2) When the on state of the near-point dog is detected, the machine starts decelerating.
(3) The machine decelerates to the speed set in [Pr.47] Creep speed and moves at the creep speed after that.
(During the deceleration, the near-point dog must be on. Otherwise the deceleration stop will occur.)
(4) After the near-point dog turns off and at the first input of zero signals, the RD75 stops outputting pulses and produces Deviation counter clear output to the
drive unit.
(Deviation counter clear signal output time is set in [Pr.55].)
(5) After Deviation counter clear output is completed, OPR complete flag ([Md.31] Status: b4) turns on and OPR request flag ([Md.31] Status: b3) turns off.
Restrictions
A pulse generator with a zero signal is required. When using a pulse generator without a zero signal, produce a zero signal
using an external signal.
2 OPR CONTROL
42
2.2 Machine OPR
V
Pr.46 OPR speed
(1)
OFF
Near-point dog
Zero signal
ON
OFF
ON
OFF
OFF
OPR
Standby
0
Inconsistent
A value of the movement amount is stored.
Inconsistent
Deceleration at the near-point dog ON
Pr.47 Creep speed
t
(2) (3) (4)(5)
Md.34 Movement amount after near-point dog ON
Adjust so that the near-point dog OFF position
ON
is as close as possible to the center of the zero
signal HIGH level.
If the near-point dog OFF position overlaps
with Zero signal, the machine OPR stop position
may deviate by one servomotor rotation.
One servomotor rotation
ON
Pr.55 Deviation counter clear signal output time
Standby
Value of *1
OP address
*1