Mitsubishi Electric RD77MS2 - Page 58

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3 MAJOR POSITIONING CONTROL
3.1 Outline of Major Positioning Controls
■Speed switching (Standard speed switching mode: Switch the speed when executing the next
positioning data.) (Page 421 [Pr.19] Speed switching mode)
• If the respective command speeds differ in the "positioning data currently being executed" and the "positioning data to carry
out the next operation", the machine will accelerate or decelerate after reaching the positioning point set in the "positioning
data currently being executed" and the speed will change over to the speed set in the "positioning data to carry out the next
operation".
• 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.
■RD77MS4 operation example
• 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 the warning "Insufficient
movement amount" (warning code: 0998H) will occur.
[When the speed cannot change over in P2] [When the movement amount is small during automatic
deceleration]
For the following relation of the speed P1 = P4, P2 = P3, P1 < P2 The movement amount required to carry out the automatic deceleration
cannot be secured, so the machine immediately stops in a speed  0 status.
OFF
ON
OFF
ON
OFF
ON
OFF
ON
Positioning
[Da.1] Operation pattern
11
11 11 01
00
V
Dwell time
t
Speed
switching
Dwell time
Positioning start signal [Y10, Y11, Y12, Y13]
Start complete signal ([Md.31] Status: b14)
BUSY signal [X10, X11, X12, X13]
Positioning complete signal
([Md.31] Status: b15)
P1 P2 P3 P4
Positioning address.
Pn Pn + 1