lri2k STMicroelectronics, lri2k Datasheet - Page 42

• Manufacturer Part Number: lri2k
• Description: 13.56 Mhz, 2048-bit Eeprom Tag Ic With 64-bit Uid And Kill Code, Iso 15693 And Iso 18000-3 Mode 1 Compliant
• Manufacturer: STMicroelectronics

Explanation of the possible cases
17
Note:
42/89
Explanation of the possible cases
Figure 40
sequence when the slot number is 16.
The different steps are:
The decision to interrupt the anticollision sequence is made by the VCD. It could have
continued to send EOFs until Slot 16 and only then sent the request to LRI2K 1.
The VCD sends an Inventory request, in a frame terminated by an EOF. The number of
slots is 16.
LRI2K 1 transmits its response in Slot 0. It is the only one to do so, therefore no
collision occurs and its UID is received and registered by the VCD;
The VCD sends an EOF in order to switch to the next slot.
In slot 1, two LRI2Ks, LRI2K 2 and LRI2K 3 transmit a response, thus generating a
collision. The VCD records the event and remembers that a collision was detected in
Slot 1.
The VCD sends an EOF in order to switch to the next slot.
In Slot 2, no LRI2K transmits a response. Therefore the VCD does not detect any
LRI2K SOF and decides to switch to the next slot by sending an EOF.
In slot 3, there is another collision caused by responses from LRI2K 4 and LRI2K 5
The VCD then decides to send a request (for instance a Read Block) to LRI2K 1 whose
UID has already been correctly received.
All LRI2Ks detect an SOF and exit the anticollision sequence. They process this
request and since the request is addressed to LRI2K 1, only LRI2K 1 transmits a
response.
All LRI2Ks are ready to receive another request. If it is an Inventory command, the slot
numbering sequence restarts from 0.
summarizes the main possible cases that can occur during an anticollision
LRI2K