Diagnosis (Function 8)
The diagnosis function provides a series of tests for checking the communication system between the master and the slave and for examining a variety of internal error states within the slave. A broadcast telegram is not supported.
The function uses two bytes in the query to specify a sub function code defining the test that is to be carried out. The slave returns the function code and the sub function code in the response.
The diagnostic queries use a two-byte data field to send diagnostics data or control information to the slave.
Query
|
Byte Name |
Modbus RTU |
Modbus ASCII | ||
|---|---|---|---|---|
|
Start - Frame |
- |
- |
":" |
0x3A |
|
Address |
11 |
0x0B |
"0B" |
0x30, 0x42 |
|
Function-Code |
8 |
0x08 |
"08" |
0x30, 0x38 |
|
Sub function high |
0 |
0x00 |
"00" |
0x30, 0x30 |
|
Sub function low |
0 |
0x00 |
"00" |
0x30, 0x30 |
|
Data high |
2 |
0x02 |
"02" |
0x30, 0x32 |
|
Data low |
3 |
0x03 |
"03" |
0x30, 0x33 |
|
Error Check, LRC/CRC |
|
0xA1, 0xC0 |
"E8" |
0x45, 0x38 |
|
End - Frame |
|
t1-t2-t3 |
CRLF |
0x0D, 0x0A |
Response
|
Byte Name |
Modbus RTU |
Modbus ASCII | ||
|---|---|---|---|---|
|
Start - Frame |
- |
- |
":" |
0x3A |
|
Address |
11 |
0x0B |
"0B" |
0x30, 0x42 |
|
Function-Code |
8 |
0x08 |
"08" |
0x30, 0x38 |
|
Sub function high |
0 |
0x00 |
"00" |
0x30, 0x30 |
|
Sub function low |
0 |
0x00 |
"00" |
0x30, 0x30 |
|
Data high |
2 |
0x02 |
"02" |
0x30, 0x32 |
|
Data low |
3 |
0x03 |
"03" |
0x30, 0x33 |
|
Error Check, LRC/CRC |
|
0xA1, 0xC0 |
"E8" |
0x45, 0x38 |
|
End - Frame |
|
t1-t2-t3 |
CRLF |
0x0D, 0x0A |
Echo a request (Sub function 0)
Sub function 0 causes the data that is sent to the slave by the master to be returned.
Coupler reset (Sub function 1)
Sub function 1 re-initializes the BC9000/BK9000. Error counters are reset, and the Bus Terminal Controller executes a self-test. No telegrams are either received or sent while the Bus Terminal Controller is being reset. The IP socket is closed.
Note Before the Controller will restart, it will send a response with Sub function 1. |
Note The BC8150 support the sub function 0 and 1. All other sub function answer with the value "0". |
Sub function | Data field (query) | Data field (response) |
|---|---|---|
0x0001 | 0x0000 | 0x0000 |
Delete All Counter Contents (Sub function 10)
Calling this sub function deletes the contents of all error counters in the Bus Terminal Controller.
|
Sub function |
Data field (query) |
Data field (response) |
|---|---|---|
|
0x000B |
0x0000 |
Echo query data |
Bus Communication Answer Counter (Sub function 11)
Returns the number of communication answers.
|
Sub function |
Data field (query) |
Data field (response) |
|---|---|---|
|
0x000C |
0x0000 |
Counter value |
Error Answer Counter (Sub function 13)
This counter contains the number of error answer telegrams that the coupler has sent.
|
Sub function |
Data field (query) |
Data field (response) |
|---|---|---|
|
0x000D |
0x0000 |
Counter value |
The following functions contain the counter states for various units. This means that the Modbus telegrams can be distinguished through their units, if, for example, a Bus Coupler is accessed by different masters.
Slave Answers (Sub function 14)
Contains the number of answers that the slave has sent.
|
Sub function |
Data field (query) |
Data field (response) |
|---|---|---|
|
0x000E |
0x0000 |
Counter value |
Number of unanswered telegrams (Sub function 15)
Contains the number of answers that the slave has not sent.
|
Sub function |
Data field (query) |
Data field (response) |
|---|---|---|
|
0x000F |
0x0000 |
Counter value |
Number of Error Answers (Sub function 16)
Contains the number of error answers that the slave has sent.
|
Sub function |
Data field (query) |
Data field (response) |
|---|---|---|
|
0x0010 |
0x0000 |
Counter value |