3-2SectionData Carrier Memory Map
27
3-2-5 DC Memory Check Function
The
MD command enables memory check. By designating the check block, it is
possible to calculate, write, and collate the CRC (Cyclic Redundancy Check)
code. The CRC code is calculated using the formula X
16
+ X
12
+ X
5
+ 1.
Command Format
Check
block byte number in HEX
(hexadecimal) code
(03H,
04H, ..., 00H (256 bytes) )
Start
address number specification range
(0000H
to FFFD)
R/W Head number
(1 for head 1 and 2 for head 2)
Specification
(C for collation and K for calculation)
MDC/K1/2XXXXXX*s
∗
Response Format
MD 0 0 *s
End
code
∗
00: Normal response (for calculation processing time only)
75: Normal data (for collation processing time only)
76: W
arning code (for collation processing time only)
Note:
The unit number is required in the 1
to N procedure.
In a check block, which is designated by the first address and the number of
bytes,
the area excluding the last two
bytes can be calculated. The check code
area is the last two bytes.
If
the user designates to write a check code (using processing code
K), the CRC
of
the data in the area to be calculated will be processed and the result will
be
written
to
the check code area. If the user designates to data collation (using pro
-
cessing code C), the CRC of the data in the area to be calculated will be pro-
cessed
and compare the result with the data in the check code area. If they coin
-