User manual

62 Publication 1756-RM093F-EN-P - January 2010
Chapter 6 Safety Application Development
Storing and Loading a
Project from Nonvolatile
Memory
In version 18 or later, GuardLogix controllers support firmware
upgrades and user program storage and retrieval by using a
CompactFlash card. In a 1756 GuardLogix system, only the primary
controller uses a CompactFlash card for nonvolatile memory.
When you store a safety application project on a CompactFlash card,
Rockwell Automation recommends you select Remote Program as the
Load Mode, that is, the mode the controller should enter following the
load. Prior to actual machine operation, operator intervention is
required to start the machine.
You can only initiate a load from nonvolatile memory:
• if the controller type specified by the project stored in
nonvolatile memory matches your controller type.
• if the major and minor revisions of the project in nonvolatile
memory matches the major and minor revisions of your
controller.
• if your controller is not in Run mode.
Loading a project to a safety-locked controller is allowed only when
the safety task signature of the project stored in nonvolatile memory
matches the project on the controller. If the signatures do not match
or the controller is safety-locked without a safety task signature, you
must first unlock the controller before attempting to update the
controller via nonvolatile memory.
Force Data
All data contained in an I/O, produced, or consumed safety tag,
including CONNECTION_STATUS, can be forced while the project is
safety-unlocked and no safety task signature exists. However, forces
must be uninstalled, not just disabled, on all safety tags before the
safety project can be safety-locked or a safety task signature can be
generated. You cannot force safety tags while the project is
safety-locked or when a safety task signature exists.
IMPORTANT
If you unlock the controller and initiate a load from nonvolatile
memory, the safety-lock status, passwords, and safety task
signature will be set to the values contained in nonvolatile
memory once the load is complete.
TIP
You can install and uninstall forces on standard tags regardless
of the safety-locked or -unlocked state.