Precautions For Using The File Register - Mitsubishi Electric Q01UCPU User Manual

4.7.6

Precautions for using the file register

(1) No registration or use of an invalid file register number
(a) When the file of the file register has not been registered
Writing to or reading from the file register will result in "OPERATION ERROR" (error code: 4101).
(b) When writing to or reading from the file register exceeding the registered size
(points)
"OPERATION ERROR" (error code: 4101) will occur.
(2) File register size check
When writing to or reading from the file register, check the file register size so that data can be written or read
within the size (points) set for the CPU module.
(a) Checking the file register size
The file register size can be checked in the File register capacity area (SD647).
The file register size data in units of 1K points is stored in this SD647.
*1 If a file register file is switched to another, the size of the currently selected file register file is stored in SD647.
The remainder after dividing the file register size by 1K points is discarded.
To ensure an accurate "range of use" check, specify the file register setting in units of 1K points (1024 points).
(b) Checking timing
• In a program using any file register, check the file register size at step 0.
• After execution of the file register file switching instruction (QDRSET), check the file register size.
• Before executing the file register block switching instruction (RSET), check that space of 1K points or more
is ensured in a block after switching. The space can be calculated using the following formula.
(File register size) > [32K points × (Switching block No.) + 1K points]
396
*1