Mitsubishi Electric MELSEC iQ-F FX5 Programming Manual page 451

Operation error
Error code Description
(SD0/SD8067)
3401H The number of digits specified by (s1) is smaller than the number of digits plus 2 of the 16-bit binary data in the device specified by (s2).
(The additional 2 digits indicate the sign (+/-) and the decimal point.)
The total number of digits specified by (s1) is out of the valid range (2 to 8).
The number of digits in the decimal part specified by (s1)+1 is out of the valid range (0 to 5).
The relationship between the total number of digits specified by (s1) and the number of digits in the decimal part specified by (s1)+1 does
not satisfy the following.
(Total number of digits)-3  Number of digits in the decimal part
3406H The device areas storing the character string specified by (d) exceed the corresponding device range.
2820H The device range specified by (s1) exceeds the corresponding device range.
8 APPLICATION INSTRUCTION
8.8 Character String Operation Instruction
8
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