Emerson manual Link Active Scheduler Block Instantiation, Rosemount 848L, Reference Manual

Reference Manual

00809-0100-4696, Rev AA September 2004

Rosemount 848L

Link Active Scheduler

Block Instantiation

The Rosemount 848L can be designated to act as the backup Link Active Scheduler (LAS) in the event that the LAS is disconnected from the segment. As the backup LAS, the Rosemount 848L will take over the management of communications until the host is restored.

The host system may provide a configuration tool specifically designed to designate a particular device as a backup LAS. Otherwise, this can be configured manually as follows:

1. Access the Management Information Base (MIB) for the Rosemount 848L.

2.To activate the LAS capability, write 0x02 to the

BOOT_OPERAT_FUNCTIONAL_CLASS object (Index 605). To deactivate, write 0x01.

3.Restart the processor.

Rosemount devices are pre-configured with function blocks at the factory, the default permanent configuration for the Rosemount 848L is listed below. The Rosemount 848L can have one additional instantiated function block.

•8 Discrete Input Blocks

•4 Discrete Output Blocks

•Multiple Discrete Input Block

•Multiple Discrete Output Block

The Rosemount 848L supports the use of Function Block Instantiation. When a device supports block instantiation, the number of blocks and block types can be defined to match specific application needs.The number of blocks that can be instantiated is only limited by the amount of memory within the device and the block types that are supported by the device. Instantiation does not apply to standard device blocks like the Resource, I/O Transducer, and Logic Transducer Block.

Block instantiation is done by the host control system or configuration tool, but not all hosts are required to implement this functionality. Please refer to your specific host or configuration tool manual for more information.

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