Omron V600 Series Operation Manual page 29

Data Carrier Memory Map
3-2-5 DC Memory Check Function
Command Format
M D
Specification
(C for collation and K for calculation)
R/W Head number
(1 for head 1 and 2 for head 2)
Start address number specification range
(0000H to FFFD)
Response Format
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
C/K 1/2 X X X
M D 0 0
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-
∗
* s
X X X
Check block byte number in HEX (hexadecimal) code
(03H, 04H, ..., 00H (256 bytes) )
Note: The unit number is required in the 1
∗
* s
to N procedure.
End code
00: Normal response (for calculation processing time only)
75: Normal data (for collation processing time only)
76: Warning code (for collation processing time only)
Section 3-2
16 12 5
+ X + X + 1.
27