Mitsubishi Electric MELSEC iQ-R Series Programming Manual page 953

Operation error
Error code Description
(SD0)
2840H A numerical value other than 2 is specified for the drive number in (s).
For the error code stored in the completion status of the operand, refer to the following.
Page 986 Error codes related to database access instructions
7 APPLICATION INSTRUCTIONS
7.21 Database Access Instructions
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