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3.10 Precautions for Use of File Registers
This section explains the precautions for use of the file registers in the QCPU.
(1) CPU modules that cannot use file registers
The Q00JCPU and Q00UJCPU cannot use the file registers. When using the file registers,
use the CPU module of other than the Q00JCPU and Q00UJCPU.
(2) Setting of file registers to be used
When using the file registers, the file registers to be used must be set with the PLC
parameter or QDRSET instruction. (The PLC parameters of the Q00CPU and Q01CPU
need not be set since they are preset to "Use file register".) If the file registers to be used
have not been set, normal operation cannot be performed with the instructions that use the
file registers.
Even when file registers to be used are not set in the PLC parameter, a program
that uses file registers can be created. For the CPU module other than the
Universal model QCPU, an error does not occur when that program is written to
the CPU module.
However, note that the correct data cannot be written/read to/from the file register.
For the Universal model QCPU, an error occurs if the program where file registers
are used is executed.
(3) Securing of file register area
(a) High Performance model QCPU, Process CPU, Redundant CPU, Universal model
QCPU
When using file registers, register the file registers to the standard RAM/memory card to
secure the file register area.
(b) Basic Model QCPU (except Q00JCPU)
The file register area has been secured in the standard RAM beforehand. The user
need not secure the file register area.
The following table indicates the memories that can use the file registers in each CPU
module.
: Can be registered, : Cannot be registered.
*1: When the flash memory is used, only read from the file registers can be performed. (Write to the flash ROM
cannot be performed.)
*2: When the E
2
PROM is used, write to the E
2
PROM can be performed with the PROMWR instruction.
*3: Unusable for the Q00UCPU and Q01UCPU.
Memory
High Performance model QCPU
Process CPU
Redundant CPU
Universal model QCPU
Basic Model QCPU
(except Q00JCPU)
Standard RAM
Memory card *1 *2
*3