Message packet formats chapter 5 – Rockwell Automation 1770-KF2 Data Highway or Highway Plus Interface Module User Manual User Manual

Page 110

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Message Packet Formats

Chapter 5

5-31

7.

WORD OFFSET — Contains the word offset between the desired
word and the beginning of the addressed file. The offset is zero for
the first word of a file. In word-range read and write commands, this
field can be combined with a symbolic file address to specify a word
address.

Bit Writes

This is a bit write command to modify the bits at the address specified by
either a word symbol, a file symbol plus a word offset, or a logical
address. This address must point to a word within a file. The function
code is 2. Unlike the current unprotected and protected bit writes in the
basic command set, this command can change the bits in a single word
only.

Command Packet:

TNS

DST

SRC

CMD

00

FNC

0F

02

00

ASCII SYMBOL
(8 CHARS. MAX.)

SET
MASK

W/F
00

TNS

STS

CMD

4F

SRC

DST

TNS

STS

CMD

4F

SRC

DST

EXT

STS

Reply Format:

(EXT STS Byte Is Optional)

B.

Format When Reporting an Error

A.

Format When Successful Execution

B.

File Symbol Address Plus Word Offset

A.

Word Symbol Address

STS

C.

Logical Address

RESET
MASK

TNS

DST

SRC

CMD

00

FNC

0F

02

00

ASCII SYMBOL
(8 CHARS. MAX.)

WORD
OFFSET

W/F
01

STS

SET
MASK

RESET
MASK

TNS

DST

SRC

CMD

FNC

0F

02

PLC-3 LOGICAL ADDRESS
(2 -51 Bytes)

STS

SET
MASK

RESET
MASK

NOTE:
This is the same as the reply packet
format for all current unprotected,
protected, and privileged bit writes.

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