Mitsubishi Electric MELSEC iQ-R Series User Manual page 485

Error code Error
(hexadecima
l)
7F20H ASCIIBIN
conversion error
7F21H Receive header
area error
7F22H Command error
7F23H MC protocol
message error
7F24H Sum check error
Description Signal
name
• When the nonprocedural PRO
or bidirectional protocol is
used, an ASCII code that
cannot be converted to
binary code was received.
• When the nonprocedural
or bidirectional protocol is
used, an odd number of
bytes of data was
received during data
communications using
ASCII  BIN conversion.
• When data is received by
PRO
Conversion Variable of the
predefined protocol
function, the data
corresponding to the
Conversion Variable
cannot be converted to
binary numbers.
• When data is received by
a Check code (ASCII
hexadecimal or ASCII
decimal) of the predefined
protocol function, the data
corresponding to the
check code cannot be
converted to binary
numbers.
• The command (frame) PRO
part designation has an
error.
• An ASCII code that
cannot be converted to
binary code was received.
• A nonexistent command, PRO
subcommand, or device
was designated.
• The remote password
length is incorrect.
• There is no data (ETX, PRO
CR-LF, etc.) following the
character area, or the
designation was incorrect.
• The sum check code P/S
calculated does not match
the sum check code
received.
• The horizontal parity code
calculated does not match
the horizontal parity code
received.
• The calculated check
code does not match the
received check code.
Corrective action Protocol
MC
• Check and correct the
transmission message from
the target device and restart
data communications.
• When the nonprocedural or
bidirectional protocol is used
and data is communicated
using ASCII  BIN
conversion, be sure to send
data in units of even bytes.
■If the predefined protocol was
edited, check if the following
values match the packet format
of the target device:
• Conversion, sign character,
number of decimals, delimiter,
number of digit for conversion
variable
• Code type and data length of
check code

• Check and correct the
transmission message from
the target device and restart
data communications.

• Check and correct the
transmission message from
the target device and restart
data communications.
• Check and correct the 
transmission message from
the target device and restart
data communications.

• Review the sum check code of
the target device.
• Review the horizontal parity
code of the target device.
• Review CRC-16 of the target
device.
■If the predefined protocol was
edited, check if the following
values match the packet format
of the target device:
• Processing method or code
type of the check code
• Data length
• Data flow
• Complement calculation
• Calculating range
Nonpr Bidire Prede
ocedu ctiona fined
ral l
 

 
27 TROUBLESHOOTING
483
27.4 Error Code List
27