Error response, Specification – Beijer Electronics NA-9379 User Manual

Page 18

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NA-9379

Specification

Revision 1.02

FnBus PIO N/A

Page 18

Quantity of Write Hi

0x00

Quantity of Write Lo

0x02

Byte Count

0x04

Write Reg. Value#0 Hi

0x11

Write Reg. Value#0 Lo

0x22

Write Reg. Value#1 Hi

0x33

Write Reg. Value#1 Lo

0x44

Response

Field name

Example

Function Code

0x17

Byte Count

0x04

Read Reg. Value#0 Hi

0x11

Read Reg. Value#0 Lo

0x22

Read Reg. Value#1 Hi

0x33

Read Reg. Value#1 Lo

0x44

- In case of address 0x0800, 0x0801 output register value: 0x0000, 0x0000 changes to 0x1122, 0x3344.

3.1.11. Error Response

In an exception response, the server sets the MSB of the function code to 1. This makes the function code value in an
exception response exactly 80 hexadecimal higher than the value would be for a normal response.

Exception Response Example

Field name

Example

Function Code

0x81

Exception Code

0x02

Exception Codes

Exception
Code

Name

Description

01

Illegal Function

The function code received in the query is not an allowable
action for the server (or slave).

02

Illegal Data Address

The data address received in the query is not an allowable
address for the server (or slave).

03

Illegal Data Value

A value contained in the query data field is not an allowable
value for server (or slave).

04

Slave Device Failure

An unrecoverable error occurred while the server (or slave)
was attempting to perform the requested action.

05

Acknowledge

The server (or slave) has accepted the request and is processing
it, but a long duration of time will be required to do so.

06

Slave Device Busy

Specialized use in conjunction with programming commands.
The server (or slave) is engaged in processing a long–duration
program command. The client (or master) should retransmit the
message later when the server (or slave) is free.

PRELIMINARY

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