RTC
®
5 PC Interface Board
Rev. 1.9 e
10 Commands And Functions
321
Undelayed
Short
List Command
list_jump_rel
Function Execution produces an unconditional jump to the specified address within the current list.
The next command there will be executed immediately without delay.
Call
list_jump_rel( Pos )
Parameter
Pos
Jump distance [(–2
20
+1) … (2
20
–1)] as a signed 32-bit value
Comments • The list_jump_rel command enables implementation of branching (e.g. “if-then-else”)
independently of the command’s list position, in particular also coded independently
of the list number because of relative addressing.
• The current input list pointer can be queried via get_list_pointer.
• list_jump_rel is usable in all list areas, including the protected list buffer (“List 3”).
• When specifying a jump distance within “List 1“ or “List 2“ or for non-indexed subrou-
tines within “List 3” be sure that the jump will not exceed the boundaries of the corre-
sponding memory area.
• If the command is used in an indexed subroutine or character set, then also be sure that
the jump won’t exceed the boundaries of the subroutine or character set.
• Illegal jump commands will be transmitted unaltered to the RTC
®
5, but will be ignored
during processing. Instead, the next command will be executed. Hence, the application
will probably no longer perform as expected. Therefore, jump commands must be care-
fully programmed (also see "Jumps", page 81).
• Jump commands initiating a jump to themselves (
Pos
= 0) will also be ignored at
runtime to prevent an infinite loop that excludes further activities (and that could only
be halted via stop_execution or an external list stop).
• Decisive are the runtime conditions. When reconfiguring list memory or converting a
subroutine, an originally legal jump address might become illegal due to new list
boundaries or a relocated subroutine storage position.
RTC
®
4
RTC
®
5 new command
Version info Last change with version OUT 517
References list_jump_pos, list_jump_rel_cond
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