User Guide

Table Of Contents
Allegro/Title-21 Tag Commands
66
No Response
General ACK Request (24h; F00Fh)
The General ACK Request, or Sign Off Request, command informs the tag that it should
not respond to any commands from the reader for the specified time period. This
command contains the following request fields:
General ACK Request Fields
FF 00 24 04 00 E4 26
SOH Length TM
OpCode
Status CRC
Field Value Description
TM OpCode 0x24 TM OpCode for tag modification operations
Timeout [2 bytes] Indicates how long the command should spend
attempting the operation, in milliseconds.
TM Options 0x00 Reserved for Future Use.
Transaction Type Code 0xF00F Allegro/Title-21 code indicating operation to per-
form.
Options [1 byte] Command specific options
Tag ID [4 bytes] Indicates the ID of the tag to operate on.
Time Out [1 byte] Indicates the amount of time the tag shall ignore
commands from the reader, in seconds from 0-127.
Condition Code Bits [1 byte] Represents a condition applicable to a tolling envi-
ronment.
LCD Message Page Pointer [1 byte] Tag memory page where the LCD message to be
displayed is stored in ASCII. Valid range = 0x02 -
0x0F.