Emerson Rosemount 2240S, Справочное руководство, Страница: 92 / 194

82
Reference Manual
00809-0100-2240, Rev DA
Configuration/Operation
October 2017
Configuration/Operation
5.13 Resource block
5.13.1 FEATURES and FEATURES_SEL
The FEATURES parameter is read only and defines which features are supported by the Rosemount
2240S. Below is a list of the FEATURES supported by the Rosemount 2240S temperature transmitter.
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 2240S is HARD W LOCK. Choose one or more of the
supported features if any.
UNICODE
All configurable string variables in the Rosemount 2240S, 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 2240S 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, 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 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 as
determined by the DEFINE_WRITE_LOCK parameter shall be rejected.
Table 5-16 on page 83 displays all possible configurations of the WRITE_LOCK parameter.