Mitsubishi A1SH, Руководство пользователя, Страница: 60 / 186

4. AnSHCPU MODULE
4 - 20
MELSEC-A
4.4.2 I/O control switch setting
The I/O control system uses either the direct mode or the refresh mode. Use the
DIP switch (SW1) to switch the I/O control mode.
On shipment from the factory, the direct mode is set for both inputs and outputs
(SW1 : ON).
ON OFF
ON
2
1
2
1
Controls both inputs and outputs in the
direct mode
ON OFF
ON
2
1
2
1
Controls both inputs and outputs in the
refresh mode
POINT
Make sure that the power is OFF be to reswitching the I/O control mode.
4.4.3 Memory write protect switch setting
The memory write protect switch is designed to protect data in the RAM memory
from being overwritten due to incorrect operation or malfunction of a peripheral
device.
It is used to prevent overwriting or deletion of created programs.
To modify data in RAM memory, the memory write protect switch must be turned
OFF.
The memory write protect switch is set to OFF (SW2 : OFF) before shipment from
the factory.
(1) When the A1SJHCPU(S8)/A1SHCPU is used
With the A1SJHCPU(S8)/A1SHCPU, ON/OFF of memory write protection is
set using a DIP switch (SW-2). The first 32 Kbytes in the user memory area
of 64 Kbytes are fixed.
When operating using an E
2
PROM, the setting of the memory write protect
switch is effective with respect to the E
2
PROM if a memory cassette is
installed.
Programs cannot be written to the internal RAM using peripheral devices
while operating the E
2
PROM.
By selecting the ON position on this switch, the parameters, the program and
a part of extension file register will be write-protected in the memory. (See
Section 4.1.9.)
ON OFF
ON
2
1
2
1
Memory write protect switch ON
ON OFF
ON
2
1
2
1
Memory write protect switch OFF