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Rockwell Automation 1770, D17706.5.16 Ref Mnl DF1 Protocol Command User Manual

Page 104

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7–17

Communication Commands

Publication 1770Ć6.5.16 - October 1996

protected typed logical read with three address fields

Reads data from a logical address in a SLC 500 module.

CMD

0F

STS

FNC

A2

TNS

DST SRC

Ele.

No.

File

Type

C

Byte

Size

File

No.

S/Ele.

No.

CMD

4F STS

TNS

SRC DST

R

DATA

EXT

STS

Field

Description

Byte Size

The size of data to be read (in bytes), not including the address

fields or other overhead bytes.

File Number

Addresses files 0Ć254 only. For higher addresses, setting this

byte to FF expands this field to three bytes total. Use the

second and third bytes for the expanded file address (low

address byte first).

File Type

Use one of the these values for this field. Do not use any other

values; doing so may result in unpredictable results.

80Ć83 hex: reserved

84 hex: status

85 hex: bit

86 hex: timer

87 hex: counter

88 hex: control

89 hex: integer

8A hex: floating point

8B hex: output logical by slot

8C hex: input logical by slot

8D hex: string

8E hex: ASCII

8F hex: BCD

Element Number

Addresses elements 0Ć254 only. For higher addresses, setting

this byte to FF expands this field to three bytes. Use the second

and third bytes for the expanded element address (low address

byte first).

SubĆelement Number

Addresses subĆelements 0Ć254 only. For higher addresses,

setting this byte to FF expands this field to three bytes. Use the

second and third bytes for the expanded subĆelement address

(low address byte first).

DATA

For SLC 5/01 or 5/02 = 82 bytes (41 words).

For SLC 5/03 or 5/04

= 225 bytes with IP (does not apply to DF1 drivers)

= 236 bytes without IP (applies to DF1 drivers)

SLC 500

SLC 5/03

SLC 5/04