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MELSEC-Q
9 MAJOR POSITIONING CONTROL
POINT
•The machine recognizes the presence of a mov ement amount change request when the data is
written to " Cd.23 Speed-position switching c ontrol movement amount change register" with the
sequence program.
•The new movement amount is validated after ex ecution of the speed-position switching co ntrol (INC
mode), before the input of the speed-position s witching signal.
•The movement amount change can be enable/dis able with the interlock function in position co ntrol
using the “speed-position switching latch fl ag” ( Md.31 Status : b1) of the axis monitor area.
Restrictions
(1) An axis error (error code: 516) will occur and the operation cannot s tart if
"continuous positioning control" or "continuous path control" is s et 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 exam ple, if
the operation pattern of positioning data No. 1 is "continuous path c ontrol",
"speed-position switching control" cannot be set in position ing 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) An error (error code: 503) will occur if "current speed (-1)" is set in " Da.8
command speed".
(4) The software stroke limit range check during sp eed control is made only when
the following (a) and (b) are satisfied:
(a) " Pr.21 Current feed value during speed control" is "1: Upd ate cu rre nt fe ed
value".
If the movement amount exceeds the software st roke limit range during
speed control in case of the setting of other th an "1: Update current feed
value", an error (error code: 507 or 508) will oc cur 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 strok e limit range check is not performed.
(5) If the value set in " Da.6 Positionin g address/movement amount" is negative,
an error (error code: 530) will occur.
(6) Deceleration processing is carried out from the point where the speed-po sition
switching signal is input if the position control movement am ount 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 stabilizat ion region
(constant speed status). A warning (warning code: 508) will occur because of
large deviation in the droop pulse amount if the signal is turned O N during
acceleration.
During use of the servomotor, the actual movement amount after switching of
speed control to position control is the "preset movement am ount + droop
pulse amount". If the signal is turned ON during acceleration/decel eration, the
stop position will vary due to large variation of the droop pulse am ount. Even
though "Md.29 Speed-position s witching control positioning amount" is the
same, the stop position will change due to a change in droop pulse am ount
when "Da.8 Command speed" is different.