User's Manual

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CRC data check with

BIS L-405-037-... Processor

Initialize data carrier

The BIS L-405-037-... processor checks for correctness of the data read using a CRC_16

checksum. This CRC_16 checksum is located in Byte 3 and Byte 4 of the data carrier. This

ensures especially high data integrity.

In order to use the CRC_16 procedure, data carriers of type BIS L-10_-05/L must first be

initialized using a BIS L-60_ _ processor and the BISCOMRW.exe PC software. Only 3

bytes of user data are then available on the data carrier.

The BIS L-405-037-... processor can only be operated with initialized data carriers

of type BIS L-10_-05/L.

☞

Data carriers of type BIS L-10_-05/L should not be used with the BIS L-405-033-...

processor, because there is no CRC-16 check.

BIS L-405-03_-00_-05-MU_834487_E_0709.p65

english14

t1 t1 t1 t1 t1

t2 t2 t2 t2 t2

CRC data check with

BIS L-405-037-...

CRC error

If the BIS L-405-037... processor detects a data carrier with an incorrect CRC_16 checks-

um, the output TP remains Low. The output STR is inverted to indicate the CRC error. The

"Tag present" LED flashes slowly.

The incorrect data can only be retrieved by changing ADR (see p. 8). The processor sets

the CRC_16 checksum to 0x00 0x00.

If you do not begin with retrieving the incorrect data, the new data will be output

the next time a data carrier with a correct CRC_16 checksum is detected.

Timing

Data carrier

with CRC error

ADR

Data

STR

= Read time ≈ 100 ms t1 = Data output before strobe ≈ 6 ms t2 = Response to address change ≤ 15 ms

Data value = 0 Byte 0 Byte 1 CRC0=0 CRC1=0 Data value = 0