9MAJOR POSITIONING CONTROL

POINT

MELSEC-Q

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)An axis error (error code: 516) will occur and the operation cannot start if "continuous positioning control" or "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.) 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 speed control is made only when the following (a) and (b) are satisfied:

(a)" Pr.21 value".

Current feed value during speed control" is "1: Update current feed

If the movement amount exceeds the software stroke limit range during speed control in case of the setting of other than "1: Update current feed value", an error (error code: 507 or 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, an error (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). A warning (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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Image 388
Mitsubishi Electronics QD75P, QD75D user manual Status b1 of the axis monitor area, Pr.21 value