Emerson Rosemount 752 FOUNDATION, Справочное руководство

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9
Reference Manual
00809-0100-4377, Rev CA
Configuration
January 2018
Configuration
MAN
In this mode, variables that are passed out of the block can be manually set for testing or override
purposes.
Other types of modes
Other types of modes are Cas, RCas, ROut, IMan and LO. Some of these may be supported by different
function blocks in the Rosemount 752. For more information, see the Function Block
Reference Manual .
Note
When an upstream block is set to OOS, this will impact the output status of all downstream blocks. The
figure below depicts the hierarchy of blocks:
2.6.2 Link active scheduler (LAS)
The Rosemount 752 can be designated to act as the backup LAS in the event that the LAS is disconnected
from the segment. As the backup LAS, the Rosemount 752 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 752.
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.
2.6.3 Block instantiation
Rosemount devices are pre-configured with function blocks at the factory, the default permanent
configuration for the Rosemount 752 is listed below. The Rosemount 752 can have up to nine additional
instantiated function blocks.

1 Proportional/integral/derivative block (tag name PID_1600)

1 Input selector block (tag name ISEL_1700)

1 Signal characterizer block (tag name CHAR_1800)

1 Arithmetic block (tag name ARITH_1900)

1 Integrator block (tag name INTEG_2000)
The Rosemount 752 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 and LCD Transducer Block.
By reading the parameter “FREE_SPACE” in the Resource block you can determine how many blocks you
can instantiate. Each block that you instantiate takes up 4.5573% of the “FREE_SPACE”.
Resource block
Transducer
block
Analog Input
(AI block)
Other
function
blocks