3-2SectionData Carrier Memory Map
25
The following are responses to Read and Auto Read commands sent to a DC
with a low battery:
RD 0 0 0 9 9 5 *
AR 0 0 0 9 9 5 *
Low battery completion code
Read data
Production date: Sept., 1995
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
DC contains a thionyl chloride-type lithium battery
. One characteristic 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 resistance 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 ef
fect on the useful life of
the battery.
EEPROM DC without Battery
The
MDL command makes it possible to check whether or
not the EEPROM of a
DC
has been overwritten 100,000 times or more by
adding the data on overwrit
-
ing operations to the management area designated by the user.
Command Format
Start
address number specification range (
jjj
0H to
jjj
5H or
jjj
8H to
jjjDH)
MDL1/2XXXXXX*s
∗
R/W Head number
(1 for head 1 and 2 for head 2)
Designate the number to be added in HEX
(hexadecimal) code (00H, 01H, 02H, ..., FFH).
Response Format
MD 7 5 *s
∗
Note: The
unit number is required in
the 1 to N procedure.
End code
75: Within 100,000 times
76:
Exceeded 100,000 times
The
management area consists of the first three bytes. If the EEPROM is
over
-
written 100,000 (0186A0) times or more, an end code warning of 76 will be
returned.
The number of overwriting
operations is written in hexadecimal code in
the
management area. It is possible to read the data from the management area
using the read command.