Rockwell Automation AutoMax Enhanced Ladder Editor - Manual (Page 79)

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Appendix D
Online Editing Memory Limits
Limits exist for the amount of memory reserved for editing programs online. The
Editor reserves a default 4096 bytes for editing programs online. However, you
can change the amount of memory reserved for online editing. See Specifying
the Amount of Memory Reserved for Editing a Program Online" in this Appendix
for more information.
Each rung that was modified or added during an online editing session is
checked against the allocated amount of reserved memory when you commit
the changes or enter test mode (that is, when you download the rungs to the
Processor). If the total number of online changes exceeds the allocated memory,
a message box appears to notify you. To continue editing a program online once
these limits have been exceeded, save the program to the PC and reĆdownload
it to the Processor.
Limitations for Editing Programs Online
You cannot add more than:
D 32 variables
D 8 timers and/or counters
D 16 labels
These limits are checked after you choose Accept from the Online menu. If the
changes exceed any limit, the Editor notifies you of the location at which the
problem(s) occurred. The changes are not downloaded to the Processor. You
can then edit the program to correct the limitation errors and reĆaccept the
program.
Restrictions for Editing Programs Online
While editing a program online you cannot add these types of variables:
D a global variable that is not already used in the configuration
D new or existing array variables
D an element of an array that is larger than the defined Maximum Array
Index
D new Software Events
Other restrictions for editing programs online:
D You can change all the properties for a newly added variable, but you
cannot add or change a variable description.
D You cannot inline edit variable or rung descriptions.
D You cannot change any Program Properties.
Some instructions use internal buffers to perform their operation. Consequently,
the state of the following instructions' operation is stored from program scan to
program scan:
D Counter instruction (CTUD)
D Array instructions (AR1, AR2, ARC, ASU, ASD)
D Shift Register instructions (SL, SR, RL, and RR)
D Set Event instruction (SET)
During online editing, the state information is only transferred if you have not
added, moved, modified, or deleted any of the instructions. The Editor warns
you when state information is not transferred.