Mitsubishi MELSEC-Q QD77MS, User Manual

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Chapter 9 Major Positioning Control
3) Speed switching condition
If the movement amount is small in regard to the target speed, the
current speed may not reach the target speed even if
acceleration/deceleration is carried out. In this case, the machine
is accelerated/decelerated so that it nears the target speed.
If the movement amount will be exceeded when automatic
deceleration is required (Ex. Operation patterns "00", "01", etc.),
the machine will immediately stop at the designated positioning
address, and a "insufficient movement amount" (warning code:
513) will occur.
[When the speed cannot change over in P2]
For the following relation of the speed
P1 = P4, P2 = P3, P1 < P2
[When the movement amount is small during
automatic deceleration]
The movement amount required to carry out the
automatic deceleration cannot be secured, so the
machine immediately stops in a speed
≠
0 status.
P1 P2 P3 P4
Positioning address.
Pn+1 Pn
(b) Front-loading speed switching mode
1) If the respective command speeds differ in the "positioning data
currently being executed" and the "positioning data to carry out
the next operation", the speed will change over to the speed set in
the "positioning data to carry out the next operation" at the end of
the "positioning data currently being executed".
2) The parameters used in acceleration/deceleration to the
command speed set in the "positioning data to carry out the next
operation" are those of the positioning data to carry out
acceleration/deceleration.
Speed switching will not be carried out if the command speeds
are the same.