Mitsubishi Electric MELSEC-Q/L Programming Manual page 130

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■Restrictions

The restrictions when specifying file registers to refresh devices are as follows.

• On QCPU, Refresh cannot be performed correctly if the use of file register which has the same name as the program is

specified by the PLC parameter. When the file register which has the same name as the program is used, refresh is

performed to the data of the file register having the same name as the program that is set at the last number in the

[Program] tab page of PLC parameter. To read/write the refresh data, specify the file register to the refresh device after

switching the file register to the corresponding one with the QDRSET instruction.

• Refresh cannot be performed correctly if the file name of file register or the drive number is changed by the QDRSET

instruction. (QDRSET instructions are not available with LCPU.) If the file name of file register or the drive number is

changed by the QDRSET instruction, link refresh is performed to the data of the setting file at the time of the END

instruction execution. To read/write the refresh data, specify the file register of the setting file at the time of the END

instruction execution. If the drive number is changed by the QDRSET instruction when "ZR" is specified for the device in the

CPU modules other than the Universal model QCPU, an error (LINK PARA ERROR (3101)) occurs. (Note that an error

does not occur when "R" is specified for the device.)

• When a block number is switched by the RSET instruction, refresh is performed to the data of the file register (R) in the

switched block number. When a block number is switched by the RSET instruction, refresh is performed to the data of the

file register (R) in the block number at the time of the END instruction execution. To read/write the refresh data, specify the

file register of the block number at the time of the END instruction execution.

Precautions when file registers in the flash memory are used

This section explains the precautions for use of the flash memory.

■Applicable flash memory

• Flash card

■Precautions

File registers in the flash memory can be only read in a sequence program.

(Write to the flash memory cannot be performed in a sequence program.)

Sequence program

When using the flash memory for the file registers, write data in advance.

Using GX Developer or GX Works2, write data to the flash card.

3 CONFIGURATION OF INSTRUCTIONS

3.10 Precautions for Use of File Registers

Flash memory

File register