Mitsubishi Electronics QD75D Loop to Lend loop is repeated by set repeat cycles, Set the Loop

9MAJOR POSITIONING CONTROL

9.2.22 LOOP

MELSEC-Q

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.

Axis 1 Positioning data No. 1

	Setting item	Setting example	Setting details
Da.1	Operation pattern	–	Setting not required. (Setting value is ignored.)
	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	–	Setting not required. (Setting value is ignored.)
	interpolated
Da.6	Positioning address/	–	Setting not required. (Setting value is ignored.)
	movement amount
Da.7	Arc address	–	Setting not required. (Setting value is ignored.)
	Command speed	–	Setting not required. (Setting value is ignored.)
Da.9	Dwell time	–	Setting not required. (Setting value is ignored.)
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".)

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