Rack Components
Section 2-3
RAM and EEPROM Cards
Data can be randomly written to and read from RAM or EEPROM Cards, making
it possible to easily stored programs. The memory of a RAM Cards is erased,
however, when power is not supplied to the CPU or when the RAM Card is re
-
moved from the CPU without first being connected to a backup battery. EE-
PROM Cards cannot be written while mounted in the CPU. Data can be written
to RAM Cards while they are mounted in the CPU by using the CVSS or by in
-
structions in the user program.
Both the RAM and EEPROM Memory Cards are equipped with write-protect
switches. Setting the write-protect switch to ON prevents data from being written
to or erased from the Card. Setting the write-protect switch to OFF allows data to
be written to or erased from the Card.
ON
OFF
Four RAM Memory Card models are available, varying in memory capacity from
8K, 16K, 32K to 64K words. Two EEPROM Memory Card models are available,
one containing 8K words of memory and the other 16K words of memory.
RAM Card Backup Battery
Insert a battery into a RAM Memory Card before mounting the Card into the
CPU. Leave the battery in its holder. Battery life expectancies are given below
.
Replace the battery within the time listed. Refer to Section 4 Inspection and
Maintenance for the battery replacement procedure.
Card
HMC-ES641
HMC-ES151
HMC-ES251
HMC-ES551
Capacity
64K bytes
Life
5 years
2 years
1 year
128K bytes
256K bytes
512K bytes
6 months
EPROM Cards
Data contained in the ROM Card is stored on EPROM chips and cannot be al-
tered or erased during the CPU’s operation. The EPROM chip is mounted to the
Memory Card and the entire pack is installed in the CPU. Once data is written to
the chip, the data will not be lost when the power to the PC is OFF.
ROM Cards are shipped unprogrammed. The ROM Card can be programmed
using a CV500-MCWjj Memory Card Writer.
The procedure for erasing EPROM Memory Card data is as follows:
1, 2, 3...
1. Open the memory card cover by pressing at an angle on the catch at the
bottom edge of the card using a pointed object, such as a pen.
2. Erase the data from the EPROM chips by exposing the window of the
EPROM chips to ultraviolet light. Any of a number of commercially available
EPROM erasers may be used. To ensure complete erasure, the Memory
Card should be subject to a minimum exposure as specified by the eraser
manufacturer.
3. Close the cover and slide the catch back into place.
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OMRON [ OMRON ELECTRONICS LLC ]
