51303940-250 Honeywell Power module Brand new

Determining Series C I/O block redundancy

The IOM blocks represent instances of the I/O Module hardware that reside on the I/O Link

network. There is a specific IOM block for each I/O Module type supported in Experion.

The IOM block is used to:

l configure the network address (the IOMNUM) of the IOM device.

o If the IOM is configured to be redundant, you enter only one IOMNUM. In either case,

only one block is created which handles communication to and from both physical

IOMs.

o The hardware design uses a set of push-in IOMNUM identifiers to reduce the chance

of duplicate IOMNUMs on the same link.

o Each IOM block generates system events and alarms for soft failures, IOM

synchronization, and IOM switchover.

Figure 9.1 Defining redundancy from the Main tab

9.2 Switchover and Secondary readiness

A switchover describes the process where a Secondary Series C module assumes the Primary

state, and the Primary Series C module assumes the appropriate Secondary state of readiness,

depending upon what triggered the switchover. A switchover can be triggered immediately upon

the detection of a fault in the Primary or upon the receipt of an operator command.

The ability of a Secondary Series C module to take over the assigned control functions of the

Primary depends upon which one of the following readiness states reflects its current state.

If Secondary

redundancy

state is

Then, the Secondary module

NotSynced

Not

synchronized

Cannot assume the Primary state. This is a state of non-readiness. Switchover has

not occurred. Ensure redundancy has been selected on the IOMs Main tab.

FoInProg

SwapInProg

Cannot assume the Primary State. In this state, the Secondary module is copying

database information from the Primary