KB 0026
Device error 0x00000005 is returned when reading or writing an S7 data block.


CATEGORY

ASComm.NET

 

SYMPTOMS

When reading from or writing to an S7 Data block the following device error is returned:

  •0x00000005 - Address does not exist or is out of range. The combination of starting register plus number of elements requested are beyond the CPU's address range.

 

CAUSE

Indicates that the data block exists on the controller, but in the Step 7 programming software the data block's 'Optimized block access' setting must be unchecked to allow external access using absolute addressing.

Data blocks with standard access have a fixed structure. In the declaration, the data elements are assigned both a symbolic name and a fixed address within the block. The address is shown in the "Offset" column. Tags in these data blocks can be addressed in both symbolic and absolute form.

Data blocks with optimized access have no fixed defined structure. In the declaration, the data elements are assigned only a symbolic name and no fixed address within the block.

ASComm.NET does not currently support symbolic addressing; only absolute addressing is supported.

Step7DB

 

RESOLUTION

Uncheck 'Optimized block access' to enable absolute addressing, re-compile the PLC program, and download to the controller.