Mitsubishi Electric MELSEC iQ-R Series Programming Manual page 1059

• If the read data (n) is 0, no processing is performed.
• An instruction which has been executed will result in non-processing if it fails to access the target module because the
module is faulty or busy in processing.
Operation error
Error code Description
(SD0)
2820H The module with the I/O number specified by (U) does not have buffer memory.
2823H The module with the I/O number specified by (H) does not have buffer memory.
The address specified by (s) is outside the range of buffer memory or CPU buffer memory.
The (n) points of data starting from the address specified by (s) are not within the range of buffer memory or CPU buffer memory.
(FROMD(P) instruction)
The (n)2 points of data starting from the address specified by (s) are not within the range of buffer memory or CPU buffer memory.
(DFROMD(P) instruction)
• If refresh settings are not made for the refresh area of the read/write enabled area in the CPU buffer
memory, the area can be used as a read/write specifiable area. Even when refresh settings are made, the
area can be used as a read/write specifiable area in the reference send range and later.
0
2048
524287
• A CPU buffer memory access device can be used to write data to the CPU buffer memory. ( MELSEC
iQ-R CPU Module User's Manual (Application))
• The FROMD(P) and DFROMD(P) instructions can read data from the buffer memory address with a
capacity exceeding 64K.
System area
Read/write enabled
Refresh area
7 APPLICATION INSTRUCTIONS
7.27 Module Access Instructions
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