Emerson Rosemount 644 Reference Manual page 17

Reference Manual
00809-0200-4728
LOI password
An LOI password can be entered and enabled to prevent review and modification of device
configuration via the LOI. This does not prevent configuration from HART
control system. The LOI password is a four-digit code that is to be set by the user. If the
password is lost or forgotten the master password is "9307". The LOI password can be
configured and enabled/disabled by HART communication via a Field Communicator, AMS
Device Manager, or the LOI.
2.4.3 Setting the loop to manual
When sending or requesting data that would disrupt the loop or change the output of the
transmitter, set the process application loop to manual. The Field Communicator, AMS
Device Manager, or LOI will prompt you to set the loop to manual when necessary.
Acknowledging this prompt does not set the loop to manual. The prompt is only a
reminder; set the loop to manual as a separate operation.
2.4.4 Failure mode
As part of normal operation, each transmitter continuously monitors its own performance.
This automatic diagnostics routine is a timed series of checks repeated continuously. If
diagnostics detect an input sensor failure or a failure in the transmitter electronics, the
transmitter drives its output to low or high depending on the position of the failure mode
switch. If the sensor temperature is outside the range limits, the transmitter saturates its
output to 3.9 mA for standard configuration on the low end (3.8 mA if configured for
NAMUR-compliant operation) and 20.5 mA on the high end (or NAMUR-compliant). These
values are also custom configurable by the factory or using the Field Communicator. The
values to which the transmitter drives its output in failure mode depend on whether it is
configured to standard, NAMUR-compliant, or custom operation. See Rosemount 644
Temperature Transmitter
operation parameters.
2.4.5 HART software lock
The HART
sources; all changes requested via HART by the Field Communicator, AMS Device manager
or the LOI will be rejected. The HART Lock can only be set via HART Communication, and is
only available in HART Revision 7 mode. The HART Lock can be enabled or disabled with a
Field Communicator or AMS Device Manager.
Lock HART software using the Field Communicator
From the HOME screen, enter the Fast Key sequence.
Device Dashboard Fast Keys
Lock HART software using the AMS Device Manager
Procedure
1. Right click on the device and select Configure.
Emerson.com/Rosemount
Product Data Sheet
®
software lock prevents changes to the transmitter configuration from all
for standard and NAMUR-compliant
3, 2, 1
Configuration
March 2021
®
or through the
17