LRI2K Request format
The request consists of:
• an SOF
• flags
• a command code
• parameters and data
• a CRC
• an EOF
Table 10. General request format
S
O
F
Request flags Command code Parameters Data CRC
E
O
F
In a request, the "flags" field specifies the actions to be performed by the LRI2K and whether corresponding fields are present or not.
The flags field consists of eight bits.
The bit 3 (Inventory_flag) of the request flag defines the contents of the 4 MSBs (bits 5 to 8).
When bit 3 is reset (0), bits 5 to 8 define the LRI2K selection criteria.
When bit 3 is set (1), bits 5 to 8 define the LRI2K Inventory parameters.
Bit No Flag
Table 11. Definitions of request flags 1 to 4
Level Description
Bit 1
Bit 2
Bit 3
Subcarrier_flag
Data_rate_flag
Inventory flag
(1)
(2)
0 A single subcarrier frequency is used by the LRI2K
1 Two subcarriers are used by the LRI2K
0 Low data rate is used
1 High data rate is used
0
The meaning of Flags 5 to 8 is described in Table 12
1
The meaning of Flags 5 to 8 is described in Table 13
0 No Protocol format extension Bit 4 Protocol Extension flag
1.
Subcarrier_flag refers to the LRI2K-to-VCD communication.
2.
Data_rate_flag refers to the LRI2K-to-VCD communication.
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Request format LRI2K
Bit No.
Flag
Table 12. Request flags 5 to 8 when bit 3 = 0
Level Description
Bit 5
Bit 6
Select_flag
(1)
Address_flag
(1)
0
0 -
0 -
Request is executed by any LRI2K according to the setting of
Address_flag
1 Request is executed only by the LRI2K in Selected state.
0
Request is not addressed. UID field is not present. The request is executed by all LRI2Ks.
1
Request is addressed. UID field is present. The request is executed only by the LRI2K whose UID matches the UID specified in the request.
Bit 7 Option flag
Bit 8 RFU
1. If the Select_flag is set to 1, the Address_flag is set to 0 and the UID field is not present in the request.
Bit No.
Bit 5 AFI flag
Bit 6 Nb_slots flag
Bit 7 Option flag
Bit 8 RFU
Flag
Table 13. Request flags 5 to 8 when bit 3 = 1
Level Description
1
0
0
0
1
0
AFI field is not present
AFI field is present
16 slots
-
-
1 slot
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