9 - 103
MELSEC-Q
9 MAJOR POSITIONING CONTROL
POINTS
•The machine recognizes the presence of a com mand speed change request when the data is
written to " Cd.25 Position-speed switching con trol speed change register" with the sequenc e
program.
•The new command speed is validated after exec ution of the position-speed switching contr ol before
the input of the position-speed switching si gnal.
•The command speed change can be enabled/disab led with the interlock function in speed contro l
using the "position-speed switching latch flag" ( Md.31 Status: b5) of the axis monitor area.
Restrictions
(1) An axis error (error code: 516) will occur and the operation cannot st art if
"continuous positioning control" or "continuous path control" is s et in
"Da.1 Operation pattern".
(2) "Position-speed switching control" cannot be set in " Da.2 Control system" of
the positioning data when "continuous path control" has been set in
"Da.1 Operation pattern" of the immediately prior positioning data. (For
example, if the operation pattern of positioning data No. 1 is "conti nuous path
control", "position-speed switching control" cannot be set in posit ioning data
No. 2.) An axis error (error code: 516) will occur and the machine will carry
out a deceleration stop if this type of setting is carried out.
(3) The software stroke limit range is only checked during speed contro l if the "1:
Update current feed value" is set in " Pr.21 Current feed value during speed
control".
The software stroke limit range is not checked when the control uni t is set to
"degree".
(4) An error (error code: 507 or 508) will occur and the operation cannot star t if
the start point address or end point address for position control excee ds the
software stroke limit range.
(5) Deceleration stop will be carried out if the position-speed switc hing signal is
not input before the machine is moved by a specified movement am ount.
When the position-speed switching signal is input during automatic
deceleration by positioning control, acceleration is carried out again to the
command speed to continue speed control.
When the position-speed switching signal is input during deceleration t o a stop
with the stop signal, the control is switched to the speed control to s top the
machine.
Restart is carried out by speed control using the restart command.
(6) A warning (warning code: 501) will occur and control is continue d by
"Pr.8 Speed limit value" if a new speed exceeds " Pr.8 Speed limit value" at
the time of change of the command speed.
(7) If the value set in "Da.6 Position ing address/movement amount" is negative,
an error (error code: 530) will occur.