165
(2) Exceptional code field
Exceptional responses from slaves are returned as exceptional response which indicates exceptional content
with the query.
Exceptional
code
Description and sample queries
01h
Incorrect FC (An incorrect FC is specified.)
・
An FC other than 01h, 03h, 05h, 08h, 0Fh, and 10h, which are supported, is specified.
02h
Incorrect address (An incorrect address is specified)
When FC 03h or 10h is specified
・
An address not listed in data addresses list is specified.
・
The address that is listed only for FC 03h in data addresses list is specified for FC 10h.
When FC 01h, 05h or 0Fh is specified
・
An address not listed in coil data addresses list is specified.
・
The address that is listed only for FC 01h in coil data addresses list is specified for FC
05h or 0Fh.
03h
Incorrect data (An abnormal value is specified in the information field.)
When FC 03h or 10h is specified
・
The following value is specified as the no. of registers: zero, odd number, or a value
exceeding the maximum value.
・
A value different from the no.of registers is specified to the no. of data bytes.
・
A value out of range is specified to a write data.
When FC 01h, 05h or 0Fh is specified
・
The following value is specified as the no. of coil data: zero, or a value exceeding the
maximum value.
・
A value different from the no. of coil data is specified to the no. of data bytes.
・
A value not specified as ON/OFF values is specified to a coil data in FC 05h.