53
7 OPTION
53
OPTION
Chapter
7
17 (0x0011) Return slave busy count (not counted up by the F331)
The count of slave-busy issued by slave is sent back.
18 (0x0012) Return bus character overrun count (not counted up by the F331)
The number of times of detecting a character overrun error in frames consistent in slave address is
read.
20 (0x0014) Clear overrun counter and flag
The overrun counter and the error flag are cleared.
■About error response
If there is any problem with request from the master, each slave will not execute the command but
return error response. In function code, the value of the requested function code + 0x80 is used.
Exception code judgment is made after the received frame.
The order of priority of exception code judgment is 1→3→2.
[Request]
Function 1 byte 0x08
Subfunction 2
bytes 0x00, 0x11
Data 2
bytes 0x00, 0x00
[Response]
Function 1 byte 0x08
Subfunction 2
bytes 0x00, 0x11
Data 2
bytes Busy
[Request]
Function 1 byte 0x08
Subfunction 2
bytes 0x00, 0x12
Data 2
bytes 0x00, 0x00
[Response]
Function 1 byte 0x08
Subfunction 2
bytes 0x00, 0x12
Data 2
bytes Character, overrun, count
[Request]
Function 1 byte 0x08
Subfunction 2
bytes 0x00, 0x14
Data N×2 bytes 0x00, 0x00
[Response]
Echo of request
Exception code No.
1 Function code error
2 Address out-of-range error
3 Data value error
To Next Page
Loading...
