Balluff BIS C-6002, Manual

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35
35 english
To be able to use the CRC check, the data carrier must first be initialized with the com-
mand identifier 12
Hex
(see 36). The CRC initialization is used like a normal write job. The
latter is rejected (with an error message) if the processor recognizes that the data carrier
does not contain the correct CRC. Data carriers as shipped from the factory (all data are 0)
can immediately be programmed with a CRC check.
If CRC_16 data checking is activated, a special error message is output to the interface
whenever a CRC error is detected.
If the error message is not caused by a failed write request, it may be assumed that one
or more memory cells on the data carrier is defective. That data carrier must then be re-
placed.
If the CRC error is however due to a failed write request, you must reinitialize the data car-
rier in order to continue using it.
The checksum is written to the data carrier as a 2-byte wide datum. Two bytes per page
are 'lost', i.e., the page size becomes 30 bytes or 62 bytes depending on data carrier type
(setup of page size see 17). This means that the actual usable number of bytes is re-
duced:
Data carrier type Usable bytes
128 bytes = 120 bytes
256 bytes = 240 bytes
511 bytes *) = 450 bytes
1023 bytes *) = 930 bytes
2047 bytes *) = 1922 bytes
2048 bytes = 1984 bytes
8192 bytes = 7936 bytes
CRC initialization
Function Description
Processing data carriers
*) The last data carrier page for these EEPROM-
based data carriers is not available.
C60_2-019_818217_0806-e.p65
36
english 36
Initializing the Data carrier for the CRC_16 data checking
The processing of this command is similar to a write command. Start address and number
of bytes have to correspond to the maximum number of data to be used.
In this example the complete memory range of a Data carrier with 128 bytes shall be used
(BIS C-1_ _-03/L with 32 byte block size). Because 2 bytes are used for the CRC only
120 bytes can be used as data bytes, hence: start address = 0, number of bytes = 120.
5.) Process subaddresses of the output buffer:
BIS C-60_2 Identification System:
2.) Process subaddresses of the input buffer in the
order shown:
3.) Process subaddresses of the output buffer: 4.) Process subaddresses of the output buffer:
6.) Process subaddresses of the output buffer:
Host:
1.) Process subaddresses of the output buffer in the
order shown:
...To be continued
until the complete
memory range is
written. See next .
01
Hex
Command designator 12
Hex
02
Hex
Start address 00
Hex
03
Hex
Start address 00
Hex
04
Hex
No. of bytes 78
Hex
05
Hex
No. of bytes 00
Hex
00
Hex
/07
Hex
Set AV-Bit, CT-Bit to 0
00
Hex
/07
Hex
Set AA-Bit, invert TO-Bit
01...06
Hex
Enter first 6 bytes of data
00
Hex
/07
Hex
Invert TI-Bit
01...06
Hex
Copy first 6 data bytes
Process subaddress of the input buffer:
00
Hex
/07
Hex
Invert TO-Bit
01...06
Hex
Enter the second 6 data bytes
00
Hex
/07
Hex
Invert TI-Bit
01...06
Hex
Copy second 6 data bytes
Process subaddress of the input buffer:
00
Hex
/07
Hex
Invert TO-Bit
Example No. 1
For configuring with
double bit header
and 8-byte buffer
size!
Function Description
Examples for protocol sequence