Mitsubishi Electric MELSEC Q Series Programming Manual page 318

6 POSITIONING CONTROL
[Caution]
Travel value of one operation cycle
[control unit]
Time required from satisfaction of trigger
conditions until reaching end point of the loop
[Program]
(1) During a FOR-ON loop, or a FOR-OFF loop, if the travel value of the specified
pass point is smaller than the travel value of one operation cycle shown below, it
will not loop-out even when trigger conditions are satisfied.
To perform a loop-out, make the travel value of the pass point larger than the
travel value of one operation cycle, or set a smaller speed command.
The travel value for which positioning is completed in one operation cycle is
shown below.
<Example> Command speed: 100.00[mm/min], Operation cycle: 0.44[ms]
100
6 [mm/s] × 0.44[ms] = 0.74[µm]
If the travel value of the pass point exceeds 0.74[ µm ], it will loop-out
normally.
(2) During a FOR-ON loop, or a FOR-OFF loop, if the time from satisfaction of trigger
conditions until reaching end point of the loop is shorter than the indicated time
below, positioning operations are not normal. Set the trigger conditions so that the
time from satisfaction of trigger conditions until reaching end point of the loop is
longer than the indicated time below.
(3) When the last positioning address is detected and the deceleration distance is not
enough for the output speed, an overrun, and a minor error (error code:211) occur.
However, a minor error does not occur if a movement amount of 0 is the last point.
Program for repetition constant-speed control is shown as the following conditions.
(1) System configuration
Constant-speed control for Axis 2 and Axis 3.
Q61P Q03UD Q172D
CPU CPU
AMP
Axis
1
M
Command speed per second
=
[control unit/s]
=
Main cycle + Time required for deceleration stop
Motion CPU control module
QX41 QY41P Q172D
LX
Start command (PX000)
AMP AMP AMP
Axis Axis Axis
2 3 4
M M
6 - 131
× Operation cycle [s]
M