Mitsubishi Electronics fx3u

/FX

3UC

PLC User's Manual - Positioning Control Edition

Built-in Positioning Functions

4 Before Programming

4.7 Items To Be Observed in Programming

B - 70

4.7 Items To Be Observed in Programming

This section describes various programming items that will not be affected by any pulse output destination

devices (hardware).

For information on the pulse output destination devices (hardware) that are affected by programming items,

refer to the following sections.

→ To use the transistor output of the main unit, also refer to Section 4.8.

→ To use the high-speed output special adapter, also refer to Section 4.9.

4.7.1 Positioning Instruction Activation Timing

The following positioning instructions can be programmed as many times as needed. However, observe the

items shown in the following table to determine the instruction activation timing.

3: If the pulse output destination device is now outputting pulses, the instruction cannot be activated. Refer

to the "Note" below.

: For the absolute position detection system, activate the ABS (FNC155) instruction after turning the

power ON for the servo amplifier. After executing this instruction, the current value will be read out from

the servo amplifier*1 only once.

Turning this instruction OFF will turn the servo amplifier OFF*1.

*1. The ABS (FNC155) instruction can be used with the absolute position detection system of the

MELSERVO-J3, -J2(S), and -H Series.

*2. Only available for FX3U and FX3UC PLCs.

Caution:

If the "pulse output monitor" (BUSY/READY) flag is on, and if a positioning instruction (excluding the ABS

instruction) or pulse output instruction (PLSR, PLSY) specifies the same pulse output destination device

as the one being used, the instruction cannot be executed.

Even after turning the instruction activation contact OFF, if the "pulse output monitor" (BUSY/READY)

flag is still on, do not execute a positioning instruction (including the PLSR and PLSY instructions) for an

output with the same output number.

Before activating such an instruction, check that the "pulse output monitor" (BUSY/READY) flag is off,

and then wait until 1 cycle or more of operation has been completed.

→ For examples of programs, refer to Chapter 12.

Description

Instruction to be used

DSZR DVIT

*2 TBL ABS ZRN PLSV DRVI DRVA

Instruction to be used

DSZR(FNC150) Zero return instruction with

DOG search function 3333333

DVIT(FNC151)*2 Interrupt Positioning

(interruption fixed-feed) 3333333

TBL(FNC152) Positioning by batch setting

method 3333333

ABS(FNC155) Current ABS value read-out

from servo amplifier*1 

ZRN(FNC156) Zero return (without DOG

search function) 3333333

PLSV(FNC157) Variable speed Pulse Output 3333333

DRVI(FNC158) Drive to Increment 3333333

DRVA(FNC159) Drive to Absolute 3333333

Pulse output destination device "Pulse output monitor" flag

Y000 M8340

Y001 M8350

Y002*1 M8360

Y003*2 M8370