Emerson Rosemount 5900C, Reference Manual

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4.13 Resource block
4.13.1 FEATURES and FEATURES_SEL
The FEATURES parameter is read only and defines which features are supported by the
Rosemount 5900C. Below is a list of FEATURES the Rosemount 5900C supports.
FEATURES_SEL is used to turn on any of the supported features that are found in the
FEATURES parameter. The default setting of the Rosemount 5900C is HARD W LOCK.
Choose one or more of the supported features if any.
UNICODE
All configurable string variables in the Rosemount 5900C, 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 5900C 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. If this bit is
set, the transmitter will actively report alerts.
SOFT W LOCK and HARD W LOCK
Inputs to the security and write lock functions include the hardware security switch, the
hardware and software write lock bits of the FEATURE_SEL parameter, and the
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 a hardware or software write lock
or no write lock capability. To enable the hardware security function, enable the
HARDW_LOCK bit in the FEATURE_SEL parameter. When this bit has been enabled the
WRITE_LOCK parameter becomes read only and will reflect the state of the hardware
switch.
In order to enable the software write lock, the SOFTW_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 “Not Locked.” Once the WRITE_LOCK parameter is set to “Locked” by the
software lock, all user requested writes shall be rejected.
Table 4-11 displays all possible configurations of the WRITE_LOCK parameter.
Table 4-11: Write_Lock Parameter
FEATURE_SEL
HARDW_LOC
K bit FEATURE_SEL
SOFTW_LOCK
bit SECURITY
SWITCH WRITE_LOCK WRITE_LOCK
Read/Write Write access
to blocks
0 (off) 0 (off) NA 1 (unlocked) Read only All
0 (off) 1 (on) NA 1 (unlocked) Read/Write All
Reference Manual Configuration
00809-0100-5901 September 2019
Rosemount 5900C Radar Level Gauge 171