Resource Block - Emerson Rosemount 644 FOUNDATION Reference Manual

Reference Manual
00809-0400-4728, Rev CA
LCD transducer block (index number 1200)
The LCD Transducer Block is used to configure the LCD display meter.
Analog input block (index number 1300 and 1400)
The Analog input function block processes the measurements from the sensor and makes them available
to other function blocks. The output value from the AI block is in engineering units and contains a status
indicating the quality of the measurement. The AI block is widely used for scaling functionality.
PID block (index number 1500)
The PID function block combines all of the necessary logic to perform proportional/integral/derivative
control. The block supports mode control, signal scaling and limiting, feed forward control, override
tracking, alarm limit detection, and signal status propagation.
The block supports two forms of the PID equation: Standard and series. You can choose the appropriate
equation using the MATHFORM parameter. The standard ISA PID equation is the default selection.
2.4.1

Resource block

FEATURES and FEATURES_SEL
The parameters FEATURES and FEATURE_SEL determine optional behavior of the Rosemount 644.
FEATURES
The FEATURES parameter is read only and defines which features are supported by the Rosemount 644.
Below is a list of the FEATURES the Rosemount 644 supports.
UNICODE
All configurable string variables in the Rosemount 644, except tag names, are octet strings. Either ASCII
or Unicode may be used. If the configuration device is generating Unicode octet strings, you must set the
Unicode option bit.
REPORTS
The Rosemount 644 supports alert reports. The Reports option bit must be set in the features bit string
to use this feature. If it is not set, the host must poll for alerts.
SOFT W LOCK
Inputs to the security and write lock functions include the software write lock bits of the FEATURE_SEL
parameter, the WRITE_LOCK parameter, and the DEFINE_WRITE_LOCK parameter.
The WRITE_LOCK parameter prevents modification of parameters within the device except to clear the
WRITE_LOCK parameter. During this time, the block will function normally updating inputs and outputs
and executing algorithms. When the WRITE_LOCK condition is cleared, a WRITE_ALM alert is generated
with a priority that corresponds to the WRITE_PRI parameter.
The FEATURE_SEL parameter enables the user to select the software write lock or no write lock
capability. In order to enable the software write lock, the SOFT_W_LOCK bit must be set in the
FEATURE_SEL parameter. Once this bit is set, the WRITE_LOCK parameter may be set to "Locked" or
"Unlocked." Once the WRITE_LOCK parameter is set to "Locked" by the software, all user requested
writes as determined by the DEFINE_WRITE_LOCK parameter shall be rejected.
Configuration
Configuration
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