Examples For Protocol Sequence - Balluff BIS C-60 3 Serie Handbuch

C60_3-025_825645_1310_e.p65
49
CRC initialization
50
Example No. 1
For parametering
with 8-byte buffer
size!
... To be continued
until the complete
memory range is
written. See next .
50 english
Function Description
Mode 1: Processing data carriers
To be able to use the CRC check, the data carrier must first be initialized with the command
identifier 12 (see 50). The CRC initialization is used like a normal write job. The latter is
Hex
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 replaced.
If the CRC error is however due to a failed write request, you must reinitialize the data carrier
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 36 for Mode 1 and
number of bytes is reduced:
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
*) The last data carrier page for these EEPROM-based data carriers is not available.
Function Description
Mode 1: Examples for protocol sequence
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.
Host:
1.) Process subaddresses of the output buffer in the
order shown:
01 Command designator 12
Hex Hex
02 Start address 00
Hex Hex
03 Start address 00
Hex Hex
04 No. of bytes 78
Hex Hex
05 No. of bytes 00
Hex Hex
00 Set AV-Bit, CT-Bit to 0
Hex
3.) Process subaddresses of the output buffer:
01...07 Enter first 7 bytes of data
Hex
00 Invert TI-Bit
Hex
5.) Process subaddresses of the output buffer:
01...07 Enter the second 7 data bytes
Hex
00 Invert TI-Bit
Hex
65 for Mode 2). This means that the actual usable
english
BIS C-60_3 Identification System:
2.) Process subaddresses of the input buffer in the
order shown:
00 Set AA-Bit, invert TO-Bit
Hex
4.) Process subaddresses of the output buffer:
01...07 Copy first 7 data bytes
Hex
Process subaddress of the input buffer:
00 Invert TO-Bit
Hex
6.) Process subaddresses of the output buffer:
01...07 Copy second 7 data bytes
Hex
Process subaddress of the input buffer:
00 Invert TO-Bit
Hex
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