User Manual

Chapter 8 System Parameters and Comm ands
- 212 - Hi-G-Tek Ltd. Micro electro nic s & A sset Tra cking Techno logy
the 2
nd
bit in the DataSeal's Fl ags parameter should be on. If the Au tom ati c
Acknowledge Random Delay flag (Reade r.AckBurstRandomDelay
property) in the DataReader is on too, the DataReader will randomly
choose 1 of 4 windows in which it will send its acknowledge.
The advantages of the automatic Burst acknowledge are:
 The acknowledge is very short (about 50ms).
 The application doesn't have to take care of it.
The disadvantages of the automatic Burst acknowledge are:
 The acknowledge does not ensure that the application received the
message.
 If the Au to ma ti c Ackn o wle dge Ran dom De la y flag is off, if more
than one DataReader receives the message, and both will try to send an
acknowledge, the RF transmissions of these acknowledges will collide.
 If Automatic Acknowledge Random Delay flag is on, for 2
DataReaders there's a chance of 25% for collision, for 3 DataReaders
35%, and for 4 DataReaders or more the probability rises to about 50%
or more.
The manual acknowledge is a normal RF command initiated by the
application. Note that DataSealLib sends this command by default when the
application gets the Burst messages from a DataReader (using the
Reader.GetBurstMessages met hod), but you have t he opport unity t o
cancel it, and/or send it when most appropriate to you. See the online
documentation for more information.
The advantages of the manual Burst acknowledge are: