MITSUBISHI ELECTRIC Mitsubishi Programmable Logic Controller QD75D - Manual (Page 413)

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MELSEC-Q
9 MAJOR POSITIONING CONTROL
9.2.22 LOOP
The LOOP is used for loop control by the repetition of LOOP to LEND.
Operation
The LOOP to LEND loop is repeated by set repeat cycles.
Positioning data setting examples
The following table shows the setting examples when "LOOP" is set in positioning
data No. 1 of axis 1.
Setting item Setting example Setting details
Da.1 Operation pattern – Setting not required. (Setting value is ignored.)
Da.2 Control system LOOP Set the LOOP.
Da.3 Acceleration time No. – Setting not required. (Setting value is ignored.)
Da.4 Deceleration time No. – Setting not required. (Setting value is ignored.)
Da.5
Axis to be
interpolated
– Setting not required. (Setting value is ignored.)
Da.6
Positioning address/
movement amount
– Setting not required. (Setting value is ignored.)
Da.7 Arc address – Setting not required. (Setting value is ignored.)
Da.8 Command speed – Setting not required. (Setting value is ignored.)
Da.9 Dwell time – Setting not required. (Setting value is ignored.)
A
x
is 1 Positioning data N
o
. 1
Da.10 M code 5 Set the LOOP to LEND repeat cycles.
Refer to Section 5.3 "List of positioning data" for information on the setting details.
Restrictions
(1) An error "Control system LOOP setting error (error code: 545)" will occur if a
"0" is set for the repeat cycles.
(2) Even if LEND is absent after LOOP, no error will occur, but repeat processing
will not be carried out.
(3) Nesting is not allowed between LOOP-LEND's. If such setting is made, only the
inner LOOP-LEND is processed repeatedly.
POINT
The setting by this control system is easier than that by the special start "FOR loop" of "High-level
Positioning Control" (refer to Chapter 10).
<Setting data>
• For special start: Positioning start data, special start data, condition data, and positioning data
• For control system : Positioning data
For the special start FOR to NEXT, the positioning data is required for each of FOR and NEXT
points. For the control system, loop can be executed even only by one data.
Also, nesting is enabled by using the control system LOOP to LEND in combination with the special
start FOR to NEXT.
However LOOP to LEND cannot be set across block. Always set LOOP to LEND so that the
processing ends within one block.
(For details of the "block", refer to Section 10.1 "Outline of high-level positioning control".)