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