User`s guide

from interrupting it. When a RETURN instruction is executed in the reaction program, the
main program priority is automatically reset to the level it had before the reaction subroutine
was called.
For further information on reactions and program priority, see the following keywords: LOCK,
PRIORITY, REACT, and REACTI in the V+ Language Reference Guide.
Error Trapping
Normally, when an error occurs during execution of a program, the program is terminated
and an error message is displayed on the system terminal. However, if the REACTE
instruction has been used to enable an error-trapping program, the V+ system invokes that
program as a subroutine instead of terminating the program that encountered the error.
(Each program task can have its own error trap enabled.)
Before invoking the error-trapping subroutine, V+ locks out all other reactions by raising the
main program priority to 254 (see Asynchronous Processing on page 46). See the description
of the REACTE instruction in the V+ Language Reference Guide for further information on
error trapping.
Subroutines
(Undefined variable: Primary.Product_Name_V)Language User's Guide, version
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