9 - 12
MELSEC-Q
9 MAJOR POSITIONING CONTROL
(4) Speed switching (Refer to " Pr.19 Speed switching mode".)
(a) Standard speed switching mode
1) If the respective command speeds differ in the "positioning data
currently being executed" and the "position ing data to carry out
the next operation", the machine will acceler ate or decelerate
after reaching the positioning point set in the "positioning da ta
currently being executed" and the speed will change over to the
speed set in the "positioning data to carr y out the next operation".
2) The parameters used in acceleration/decelerat ion to the
command speed set in the "positioning data to carry out the next
operation" are those of the positioning data to c arry out
acceleration/deceleration.
Speed switching will not be carried out if the c ommand speeds
are the same.
OFF
ON
OFF
ON
OFF
ON
OFF
ON
11 11 11 01 00
VDwell time
t
Speed
switching
Da. 1 Operation pattern
Positioning
Start complete signal
BUSY signal
Positioning complete signal
Positioning start signal
[XC, XD, XE, XF]
[X10, X11, X12, X13]
[Y10, Y11, Y12, Y13]
Dwell time
[X14, X15, X16, X17]
Fig. 9.4 Operation for the standard speed swit ching mode
3) Speed switching condition
If the movement amount is small in regard to t he target speed, the
current speed may not reach the target speed ev en if
acceleration/deceleration is carried out. In this case, the m achine
is accelerated/decelerated so that it nears t he target speed.
If the movement amount will be exceeded when automatic
deceleration is required (Ex. Operation patt erns "00", "01"), the
machine will immediately stop at the designated positio ning
address, and a "insufficient movement distance warnin g (warning
code: 513)" will occur.