User Guide

Table Of Contents
Allegro/Title-21 Tag Commands
74
No Response
TDMA Read Request (28h; E003h)
The TDMA Read Request command returns the tag ID from the first tag to respond
only. This command contains the following request fields:
TDMA Read Request Fields
Examples
An example command is:
ACK Response
FF 00 28 04 00 25 AA
SOH Length TM
OpCode
Status CRC
Field Value Description
TM OpCode 0x28 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 0xE003 Allegro/Title-21 code indicating operation to per-
form.
Options [1 byte] Command specific options
Number of Slots [1 byte] Specifies how many slots are available for the tags
to choose from. Valid values from 0x01-0xFF
FF ?? 28 ?? ?? 00 E0 03 ?? ?? ?? ??
SOH Length TM
OpCode
Timeout
(ms)
TM
Option
Transaction
Type Code
Option Number
of Slots
CRC
FF 0B 28 00 00 00 E0 03 ?? ?? ?? ?? ?? ?? ??
SOH Length TM
OpCode
Status TM
Option
Transaction
Type Code
Option Tag ID CRC