ThingMagic Autonomous Configuration Tool - Manual (Page 26)

Processing Data from the Reader
Autonomous Configuration Tool v1.0 User Guide 26
Read-Cycle Reset/Keep-Alive
The Read-Cycle Reset/Keep-Alive message are sent once per second and always have a
non-0x0000 Status Word, with 0x0400 indicating normal.
Table 7: Read-Cycle Reset Packet Format
Message Example
A sample Read-cycle Reset/Keep-alive message indicating normal:
A sample Read-cycle Reset/Keep-alive message indicating over-temperature, RF being
throttled temporarily:
Field Value Description
Header (Hdr) 0xFF Defines the start of the packet.
Data Length (Len) 0x00 Cycle reset contains no additional data after the status code.
OpCode 0x22 Autonomous reader message
Status Word [2 bytes]
• 0x0400 indicates a read-cycle start message...also acts
as a heartbeat when the reader is reading but no tags are
in the field.
• 0x0504 indicates the maximum temperature of the
module (85C as reported by Temperature Status
Message ) has been exceeded and reading has been
temporarily throttled.
• Other non-0x0000 fault code. See readerʼs Hardware
Guide for list of fault-codes.
CRC-16
Checksum [2 bytes] See CCITT CRC-16 Calculation .
FF 00 22 04 00 84 E0
SOH Length OpCode Status Word CRC
FF 00 22 05 04 85 E4
SOH Length OpCode Status Word CRC