TransCore IT241005422 Manual De Usuario

The host maintains control of the sequence numbers for commands and their associ-
ated responses. 

A command is not complete until a response with a proper sequence number is 
received from the programmer. 

A response is not complete until the host changes the command sequence number 
from the previous command. 

If the command sequence number does not change, the response is retransmitted by 
the programmer.

Sequence numbers for asynchronous response communications sequences are main-
tained by the programmer. 

An asynchronous response transmission sequence is not complete until an ACK is 
received from the host with a proper sequence number. 

An ACK is not complete until the programmer changes the data sequence number. 

If the data sequence number does not change, the ACK is retransmitted by the host.

To prevent asynchronous messages from being interpreted as command responses 
when host and programmer sequence numbers pass each other, the host sequence 
numbers should be odd (1,3,5,7,...,63) and programmer sequence numbers should be 
even (0,2,4,6,...,62).

Tag data or diagnostics data will generate asynchronous responses, that is, responses 
that have no associated commands. If the host begins sending a command during this 
time, the host ignores the asynchronous response. The programmer automatically 
retransmits the asynchronous response following the command execution.

The command list (Table D-5) describes the command requests that are used between 
the programmer and the host computer and/or lane controller. Within the list, the com-
mands are further divided according to their functionality, for example, communica-
tions and real-time clock.