Change Configuration On The Fly (CCOTF)

CCOTF Rules for Hot Standby

All M580 BMEH58•040 and BMEH58•040S CPUs support CCOTF. CCOTF is enabled in the Configuration tab of the CPU, in the Configuration Online Modification area, by selecting Online modification in RUN or STOP.

For information about CCOTF for M580 safety CPUs, refer to the Modicon M580 Safety Manual.

CAUTION

RISK OF UNINTENDED OPERATION

Confirm that the following preconditions exist before starting a CCOTF operation:

The application running in the Hot Standby system does not trigger a swap.
No condition exists that could forseeably cause a switchover.

Always apply a CCOTF transaction on the Primary CPU.

If a swap or switchover occurs after a CCOTF has been performed on the primary CPU, and the application has not been transferred to the standby CPU, then the behavior of the application is unpredictable.

Failure to follow these instructions can result in injury or equipment damage.

NOTE: To download CCOTF changes to a Hot Standby system:

Always apply a CCOTF transaction to the primary CPU.
Confirm the Hot Standby system is operational with a healthy Hot Standby link between the two CPUs.
Confirm that the impacted Ethernet RIO drop is operational, with a healthy Ethernet RIO link.

CCOTF allows modifications of a Hot Standby primary PAC configuration in RUN mode. The changes that can be made in the primary PAC are as follows:

Add a discrete or analog module in a free slot.
Delete a discrete or analog module.
Modify the configuration and adjustment parameters of a module.

The changes that can be made in an Ethernet RIO drop are as follows:

Add an (e)X80 or Quantum RIO drop.
Add a discrete or analog module in a free slot.
Delete a discrete or analog module.
Modify the configuration and adjustment parameters of a module.

Any CCOTF changes made to the primary PAC configuration are not automatically transmitted to the standby PAC. Instead, the standby PAC continues to be configured with its original application program.

CCOTF does not support all changes to the configuration. The following rules apply to CCOTF changes made to the primary Hot Standby PAC configuration:

A single CCOTF change can include multiple edits to multiple configuration objects.
Edits to configuration objects are atomic: only one change can be made to a single configuration object. For example, you cannot add then delete the same I/O module in a single CCOTF change.
CCOTF edits cannot be made to distributed equipment.
For an (e)X80 or Quantum RIO drop, the following limits apply to changes made in the same CCOTF session:
- Up to four modifications to the same RIO drop can be included in a single CCOTF change. For example:
  
  - Up to four I/O modules can be added to the same RIO drop.
  
  - Up to four I/O modules can be removed from the same RIO drop.
  
  - Up to four parameters can be edited for one I/O module in the same RIO drop.
- No edits can be made to an adapter module.
- No edits can be made to BMXERT1604 modules (time stamp).
- The RPI setting for the RIO drop cannot be changed.
IP addresses cannot be changed.
Only one CCOTF change may be made to a single RIO drop. Before an additional CCOTF change can be made to the same RIO drop, transfer the application program from the primary PAC to the standby PAC.

NOTE: You can set Control Expert to Virtual connected mode to test whether a proposed change to the configuration is a CCOTF event.

When CCOTF changes are made to the primary PAC, the Logic_Mismatch_Allowed flag in the T_M_ECPU_HSBY DDT determines if the standby PAC can continue to operate online. If logic mismatches are not allowed, the standby PAC transitions to wait state.

CCOTF changes can be made to the primary PAC if the Number of modifications setting in Control Expert is not reached. When the number of allowed modifications is reached:

No additional CCOTF changes can be made to the primary PAC. The Build → Build Changes command in Control Expert is disabled.
You need to transfer the application program in the primary PAC to the standby PAC.