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MELSEC-Q
10 DEVICES
(1) Designating file registers for use
The standard RAM or the memory card file registers which are to be used in the
sequence program are determined at the "PLC file" tab screen in the “(PLC)
Parameter" dialog box.
(b)
(c)
(a)
(a) When selecting "Not used"
This setting should be selected for the following cases:
• When not using the file registers
• When designating the file registers to be used in the sequence program.
The QDRSET instruction is used to designate which file registers are to
be used.
(b) When selecting "Use the same file name as the program"
1) This setting should be selected when the file registers having the same
file name as the sequence program are to be used.
2) If the program is changed, the file registers are automatically changed
to conform to the new program name.
There are also cases where it is convenient to use the file registers as
local devices which can only be used with the program currently being
executed.
3) The number of file register to use can be set by writing to PLC online.
When file registers (A to C) having the same name as the programs (A to C) are to be used,
operation is as shown below.
Example
Program A execution
Program B execution
Program C execution
File register A
File register B
File register C
R0
R0
R0
Synchronized
Synchronized
Synchronized
At program A execution --- File register A is accessed.
At program B execution --- File register B is accessed.
At program C execution --- File register C is accessed.