Emerson Rosemount 8800D Series, Reference Manual

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9
Reference Manual
00809-0100-4772, Rev FA
Configuration and Operation
March 2016
Configuration and Operation
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, 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 a hardware or software write lock or
no write lock capability. To enable the hardware security function, enable the HW_SEL 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 SW_SEL 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 either the software or the hardware lock, all
user requested writes as determined by the DEFINE_WRITE_LOCK parameter shall be
rejected.
The DEFINE_WRITE_LOCK parameter allows the user to configure whether the write lock
functions (both software and hardware) will control writing to all blocks, or only to the
resource and transducer blocks. Internally updated data such as process variables and
diagnostics will not be restricted by the security switch.
Table 2-1 displays all possible configurations of the WRITE_LOCK parameter.
Table 2-1. Configurations of the WRITE_LOCK Parameter
2.6.2 MAX_NOTIFY
The MAX_NOTIFY parameter value is the maximum number of alert reports that the
resource can have sent without getting a confirmation, corresponding to the amount of
buffer space available for alert messages. The number can be set lower, to control alert
FEATURE_SEL
HW_SEL bit
FEATURE_SEL
SW_SEL bit
SECURITY
SWITCH WRITE_LOCK
WRITE_LOCK
Read/Write DEFINE_WRITE_LOCK
Write
access to
blocks
0 (off) 0 (off) NA 1 (unlocked) Read only NA All
0 (off) 1 (on) NA 1 (unlocked) Read/Write NA All
0 (off) 1 (on) NA 2 (locked) Read/Write Physical Function
Blocks
only
0 (off) 1 (on) NA 2 (locked) Read/Write Everything None
1 (on) 0 (off)
(1)
1. The hardware and software write lock select bits are mutually exclusive and the hardware select has the highest priority. When the HW_SEL bit if set
to 1 (on), the SW_SEL bit is automatically set to 0 (off) and is read only.
0
(unlocked)
1 (unlocked) Read only NA All
1 (on) 0 (off) 1 (locked) 2 (locked) Read only Physical Function
Blocks
only
1 (on) 0 (off) 1 (locked) 2 (locked) Read only Everything None
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