Filter
Top Products
21
2-6 Operating without a Backup Battery
An EEPROM or EPROM Memory Cassette can be used together with various
memory settings to enable operation without a backup battery. The following
conditions must be met.
1, 2, 3... 1. The user program must be written to an EPROM or EEPROM Memory Cas-
sette.
2. The clock cannot be used. (A battery is required to run the internal clock.)
3. The PC Setup must be set to not detect low battery voltage.
4. The system must be designed to run properly even if DM area data is lost.
5. The Output OFF Bit (SR 25215) must be programmed to remain OFF. (The
status of this bit will be unstable without a battery.)
25314 (Always OFF Flag)
25215
6. The Forced Status Hold Bit (SR 25211) and Data Retention Control Bit
(SR 25212) must be set to be cleared in the PC Setup. (The status of these
bits will be unstable without a battery.)
7. The DIP switch on the CPU Unit must be set so that pin 1 is OFF and pin 2 is
ON.
If these conditions can be met, use the following procedures to operate without a
backup battery.
1, 2, 3... 1. Allocate UM area using the SYSMAC Support Software (SSS) if you want to
use Expansion DM for Special I/O Units or if you want to store I/O comments
in the PC.
2. Write and transfer the user program, including a line using the Always OFF
Flag (SR 25314) to ensure that the Output OFF Bit (SR 25215) remains
OFF.
25314 (Always OFF Flag)
25215
3. Set the following in the PC Setup
DM 6601 = 0000 (To reset Forced Status Hold Bit (SR 25211) and I/O Status
Hold Bit (SR 25212) at startup)
DM 6655 bits 12 to 15 = 1, bits 4 to 7 = 0 (To not detect low battery voltage)
DM 6600 and DM 6602 to DM 6654 = As required by the application.
4. Set Fixed DM (including the Communications Board settings in DM 6144 to
DM 6599) and Expansion DM as required by the application.
5. Check operation.
6. Mount the Memory Cassette in the CPU Unit.
7. Switch to PROGRAM mode.
8. Turn ON SR 27000 to transfer the program, Fixed DM, and the PC Setup to
the Memory Cassette. (This bit will automatically reset itself if turned ON
from a Programming Console. It will need to be turned OFF by clearing
forced status if it is set from the SSS.)
9. Turn ON the write protect switch on the Memory Cassette.
10. Turn OFF pin 1 and turn ON pin 2 on the DIP switch on the CPU Unit to auto-
matically transfer the program, Fixed DM, and the PC Setup from the
Memory Cassette when power is turned ON.
EEPROM Memory Cassette
Operating without a Backup Battery Section 2-6