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Sts byte, Local sts error codes – Rockwell Automation 1770, D17706.5.16 Ref Mnl DF1 Protocol Command User Manual

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Message Packet Status Codes (STS, EXT STS)

Publication 1770Ć6.5.16 - October 1996

The STS byte provides information about the execution or failure of
the corresponding command that was transmitted from the computer.
If the reply returns a code of 00, the command was executed at the
remote node. All other codes can be divided into two types:

This error type

Occurs when

local

the local node is unable to transmit a message to the remote node.

The local node interface turns the command around, stuffs the STS

byte with the appropriate code, and returns it to the computer.

remote

the command is successfully transmitted to a remote node, but the

remote node is unable to execute the command. The remote node

formats a reply message with the appropriate remote error code in

the STS byte.

The STS byte is divided into two nibbles (4 bits each):

Bit:

7

6

5

3 2

1

0

4

Remote Error
Nibble

Nibble

Local Error

contains errors found by the

remote node receiving the

command

contains errors found by

the local node

Local STS Error Codes

The local STS error code nibble contains errors found by the local
node. Error codes (in hex) that you may find in the local error code
nibble include:

Code

Explanation

00

SuccessĊno error

01

DST node is out of buffer space

02

Cannot guarantee delivery: link layer

(The remote node specified does not ACK command.)

03

Duplicate token holder detected

04

Local port is disconnected

05

Application layer timed out waiting for a response

06

Duplicate node detected

07

Station is offline

08

Hardware fault

Local STS codes 09 through 0F (hex) are not used.

STS Byte