Sram Data Carrier Battery Check - Omron V600-CA8A-V Series Operation Manual

Data Carrier Memory Map

3-2-4 SRAM Data Carrier Battery Check

1, 2, 3...
4. If start address is greater than the end address (start address > end ad-
dress), the write-protected area will wrap through 0006, so that addresses
from 0006 through the end address,and from the start address through
07FF will be write-protected.
Address
0000
É É É É É
0006
É É É É É
É É É É É
07FF
É É É É É
The life of the battery of the DC that incorporates SRAM can be checked with the
Parallel Interface Controller.
The record of the number of overwriting operations of the DC that incorporates
EEPROM should be managed by the user's program. Unlike the Serial Interface
Controller, however, the MDL command cannot be used with the DC.
Data Carrier battery checks are not performed automatically, only when the con-
tents of the production date area (addresses 0000 and 0001) are read. Too much
power would be consumed if a battery check was performed automatically every
time DC memory was accessed. When a battery check is performed, a small
current is passed through the DC's internal circuitry.
To execute a battery low check, set page 0 with DIP switches 1 and read address
00 (the month area of the production date (month, year) area).
Low battery check command:
1. Read command
2. Auto read command
C1 C0
0 0
1 0
7B (hexadecimal) is output as a low battery response to the ID Controller's RD0
to RD7.
RD7 RD6
0 1
At that time, the read data of address 00 will not be output. The ID Controller indi-
cates an error by turning OFF the error line "ERR."
Under ordinary operating conditions the DC can be used for about 1 month after
a low battery completion code is received. However, it is recommended that the
Data Carrier battery be replaced with a new one as soon as possible.
Note The SRAM DC contains a thionyl chloride-type lithium battery. One characteris-
tic of this type of battery is its tendency to develop a higher internal resistance
when it is not used. If the battery isn't used for several months, the internal resis-
tance can increase enough to cause a low battery response, even if the battery is
good.
Consequently, after several months of disuse it is recommended to transmit data
to/from the DC for about 10 minutes to "warm up" the battery and decrease its
internal resistance. This operation will have almost no effect on the useful life of
the battery.
End address
Start address
RD5 RD4 RD3
1 1 1
7
Section
RD2 RD1 RD0
0 1 1
B
3-2
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