Mitsubishi Electronics FX1S Index Registers, Use of Modifiers with Applied Instruction Parameters

FX Series Programmable Controllers Devices in Detail 4

4.13Index Registers

FX1S FX1N FX2N FX2NC

Device Mnemonic: V,Z

Purpose: To modify a specified device by stating an offset.

Alias: (V/ Z) Register

Index (register/ addressing/ modifier)

Offset(s) (register/ addressing/ modifier)

Indices

Modifier

Available forms:

For 16bit data V or Z (2 devices)

For 32bit data V and Z combined (1 device - Z is specified)

Operation is similar to data registers.

16 Bit	16 Bit
V	Z
	32 Bit
V	Z

Devices numbered in: FX1S, FX1N, there are two devices V and/ or Z.

For FX2N and FX2NC there are 16 devices V0 - V7 and Z0 - Z7

Further uses: Can be used to modify the following devices under certain conditions; X, Y, M, S, P, T, C, D, K, H, KnX, KnY, KnM, KnS

Example device usage:

The program shown right transfers data from D5V to D10Z.

If the data contained in register V is equal to 8 and the data in register Z is equal to 14, then:

V = 8

D5V

D5 +8 =13 ➭ D13

Z = 14

D10Z

D10 + 14 = 24 ➭ D24

Hence, the actual devices used after the modifiers V and Z have been taken into account are; D13 and D24 and not D5 and D10 respectively.

Use of Modifiers with Applied Instruction Parameters:

•All applied instruction parameters should be regarded as being able to use index regis- ters to modify the operand except where stated otherwise.

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