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MELSEC-Q
9 MAJOR POSITIONING CONTROL
POINT
•
The machine recognizes the presence of a movement amount change request when the data is
written to "
Cd.23
Speed-position switching control movement amount change register" with the
sequence program.
•
The new movement amount is validated after execution of the speed-position switching control (INC
mode), before the input of the speed-position switching signal.
•
The movement amount change can be enable/disable with the interlock function in position control
using the “speed-position switching latch flag” (
Md.31
Status : b1) of the axis monitor area.
Restrictions
(1) The axis error "Continuous path control not possible" (error code: 516) will
occur, and the operation cannot start if "continuous path control" is set in
"
Da.1
Operation pattern".
(2) "Speed-position 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 "continuous path control",
"speed-position switching control" cannot be set in positioning data No. 2.) The
axis error "Continuous path control not possible" (error code: 516) will occur
and the machine will carry out a deceleration stop if this type of setting is
carried out.
(3) The error "No command speed" (error code: 503) will occur if "current speed (-
1)" is set in "
Da.8
Command speed".
(4) The software stroke limit range check during speed control is made only when
the following (a) and (b) are satisfied:
(a) When "
Pr.21
Current feed value during speed control" is "1: Update
current feed value"
If the movement amount exceeds the software stroke limit range during
speed control in cases of settings other than the one above, the error
"Software stroke limit+" (error code: 507) or "Software stroke limit–" (error
code: 508) will occur as soon as speed control is changed to position control,
and the axis will decelerate to a stop.
(b) When "
Pr.1
Unit setting" is other than "2: degree"
If the unit is "degree", the software stroke limit range check is not performed.
(5) If the value set in "
Da.6
Positioning address/movement amount" is negative,
the error "Outside address range" (error code: 530) will occur.
(6) Deceleration processing is carried out from the point where the speed-position
switching signal is input if the position control movement amount set in
"
Da.6
Positioning address/movement amount" is smaller than the
deceleration distance from the "
Da.8
Command speed".
(7) Turn ON the speed-position switching signal in the speed stabilization region
(constant speed status). The warning "Speed-position switching (during
acceleration) signal ON" (warning code: 508) will occur because of large
deviation in the droop pulse amount if the signal is turned ON during
acceleration.
During use of the servomotor, the actual movement amount after switching of
speed control to position control is the "preset movement amount + droop
pulse amount". If the signal is turned ON during acceleration/deceleration, the
stop position will vary due to large variation of the droop pulse amount. Even
though "
Md.29
Speed-position switching control positioning amount" is the
same, the stop position will change due to a change in droop pulse amount
when "
Da.8
Command speed" is different.
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