Scanlab RTC 5 PC Interface Board Installation And Operation Manual page 321

Undelayed list_jump_rel
Short
List Command
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
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
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
• 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
• 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,
®
RTC 5 PC Interface Board
Rev. 1.9 e
10 Commands And Functions
20
Jump distance [(–2 +1) ... (2
"Jumps", page
stop_execution or an external list stop).
list_jump_rel_cond
20
–1)] as a signed 32-bit value
®
5, but will be ignored
81).
321