Rockwell Automation 57C620 AutoMax Programming Executive Version 3.8 - Manual (Page 285)

PĆ7 Version Control Library (VCL)
Tokens and Locking during a Fetch Operation
If the check box labeled Fetch all available Tokens is selected (checked), then all
the tokens in the Version Control Library within the scope of the fetch operation
will be transferred to the AutoMax library. If the user wants to write over any files
whose tokens are already in the AutoMax library, he may be required to enter the
token password.
When using both the See List of Snapshots option and the option to fetch all
available tokens, be careful when selecting a snapshot from the list box. There is
a chance that modifications that were made to the files in the VCL will be lost. For
example:
John and Tim both have a copy of the same system and are using the same
Version Control Library. They are both working on system SYS1, which has
one section, SECT1, and two racks, RACK1 and RACK2. John has the token
for RACK1 and has been making changes to RACK1. Tim has the token for
RACK2 and has been making changes to RACK2.
John finishes his changes to RACK1 and does a section snapshot of SECT1.
He uses the Move Tokens to VCL" option because he is done modifying
RACK1. (John probably should have only done a rack snapshot since he
held the token for RACK1 only.) After the snapshot is complete, the token for
RACK1 is held by the Version Control Library.
Tim finishes his changes to RACK2 and does a rack snapshot using the
Move Tokens to VCL" option. He uses the Move Tokens to VCL" option
because he is finished making changes to RACK2. Now the token for RACK2
is held by the Version Control Library.
John decides to fetch SECT1. He chooses the snapshot from above, along
with the Fetch all available Tokens" option. The fetch will retrieve both racks
exactly like they were when SECT1 was snapshot, along with both rack
tokens. John's copy of RACK2 is now the current" copy and Tim's changes
are lost.
When fetching from the VCL, locks are taken out in the AutoMax library for the
appropriate SSRT. For example, if a user is fetching a section, a lock will be taken
out in the AutoMax library for that section. No one else can modify the section
until the first user's fetch is complete. If the Fetch Latest" option is being used,
locks are also taken out in the VCL so that no one can snapshot anything and
modify the latest" version.