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11 SUB FUNCTIONS
11 - 10
[2] Precautions during control
When utilizing the target position change function, pay attention to the following:
(1) The target position can be changed any number of times during a control.
When changing the target position several times during 1-axis linear control
(INC), a newly specified target position is always identified as the movement
amount from the start address.
(2) If the work is under acceleration to the commanded speed at the point where
the target position request is input, after the commanded speed is reached,
perform positioning for the newly specified target. (Actions shown in (1) or
(2))
After acceleration, however, if deceleration to stop is started without
switching to the commanded speed, positioning for the newly specified target
must be done after completion of the deceleration stop.
(3) If the target position change request is input several times during
acceleration or during deceleration stop, positioning is performed to the
target position set in " Cd. 11 Target position change value" at the last time
the request is input.
(4) When using the target position change function and the speed change
function together, pay attention to the following:
(a) When " Cd. 10 Target position change request" turns ON during speed
control, the processing for the target position change is performed after
completion of the speed change.
If the speed change value is 0pps, however, only the target position is
changed with no movement. When the speed is changed to other than
0pps next time, positioning is performed to the target position.
(b) When " Cd. 6 Speed change request" and " Cd. 10 Target position
change request" turn ON at the same time, "Speed change not
possible" (Warning code: 22) is generated.
(5) At the point where " Cd. 10 Target position change request" turns ON, the
software stroke limit check is performed on the value set for " Cd. 11 Target
position change value".
If the " Cd. 11 Target position change value" is more than the upper limit
value or less than the lower limit value, the target position is not changed and
the positioning performed before the change request is continued.
In this case, " Cd. 6 Speed change request" and " Cd. 10 Target position
change request" will not be accepted after that.
(6) The target position change function is not allowed in the following cases:
(a) While the axis operation is stopped or is in standby status, "Cd.10
Target position change request" is ignored.
(b) When the target position change is requested after restart, "Target
position change not possible" (Warning code: 25) is generated.
(c) When the target position change is requested in other than position
control (Operation pattern: Positioning termination), "Target position
change not possible" (Warning code: 25) is generated.
MELSEC-Q
11 - 10
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