User Manual

September 2001 S6350 Reader Reference Guide
29
Response Packet Format
Standard reader Response Packet Format (See Section 3.1)
ISO Response
Data
Header Packet
Length
Node
Address
Response
Flags
Command Checksum
‘01
hex
’ LSB MSB LSB MSB Flags ‘60
hex
’
Data
bytes
0 - ‘m’
Byte 1 Byte 2
1 byte 2 bytes 2 bytes 1 byte 1 byte ‘m’ bytes 2 bytes
Response Packet Description
Field Length Description
Header 1 byte Defines the start of the packet (01
hex
).
Packet
Length
2 bytes Defines the length of the packet, including checksum.
Node
Address
2 bytes Defines the Node address of the reader.
Response
Flags
1 byte Defines the response of the reader to the request. Bit 4 defines the
error status; a set value indicates that an error has occurred. (Other
values reserved for future use)
Command 1 byte Defines the command that the reader executed (60
hex
for ISO 15693-3
commands)
Data 0-m
bytes
Defines the data returned by the reader in response to a command.
Checksum 2 bytes Byte 1 is an XOR checksum of all elements from the header to the
last byte of the data field. Byte 2 is calculated as (FF
hex
) XOR (byte 1)