Setting The Loop To Manual; Failure Mode - Emerson Rosemount 644 HART Reference Manual

Temperature transmitter, for product shipped before september 2012
Table of Contents
Configuration
July 2016
Figure 2-3. LOI Configuration Buttons
A. Configuration buttons
Table 2-2. LOI Button Operation
Local Operator Interface password
A Local Operator Interface Password can be entered and enabled to prevent review and
modification of device configuration via the LOI. This does not prevent configuration from HART
or through the control system. The LOI password is a 4 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.
Local Operator Interface menu trees are available in
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
12
Button
Left
Right
A
No
Yes
Appendix D: Local Operator Interface
Reference Manual
00809-0100-4728, Rev MB
SCROLL
ENTER
(LOI).
Configuration
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