User`s guide

Polling Mode
10-9
Restrictions Introduced by Polling Mode
As explained above, polling mode executes the Simulink-based target
application in real time exclusively. While the target application is executing
in polling mode, the background tasks, mainly the ones for host-target
communication and target screen updating, are inactive. This is because all
interrupts of the target PC are fully disabled during the execution of the target
application. On one hand this ensures the highest polling performance; on the
other hand, as a consequence the background tasks are not serviced.
Here is a list of all relevant restrictions of polling mode, which are otherwise
available in the default interrupt mode.
Host-Target Communication Is Not Available During the Execution of the
Target Application
If the target application execution is started in polling mode, e.g., with
start(tg)
host-target communication is disabled throughout the entire run, or in other
words until the stop time is reached. Each attempt to issue a command like
tg
leads to a communication-related error message. Even the start(tg)
command to start polling mode execution returns such an error message,
because the host side does not receive the acknowledgment from the target
before timing out. The error message when executing
start(tg) is not
avoidable. Subsequently, during the entire run, it is best not to issue any
target-related commands on the host, in order to avoid displaying the same
error message over and over again.
As a consequence, it is not possible to issue a
stop(tg) command to stop the
target application execution from the host side. The target application has to
reach its set stop time for polling mode to be exited. You can use
tg.stoptime=x
before starting the execution, but once started the application executes until
the stop time is reached.
Nevertheless, there is a way to stop the execution interactively before reaching
the target application stop time. See “Controlling the Target Application” on
page 10-12.