Emerson Rosemount 644, Reference Manual

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12
Reference Manual
00809-0200-4728, Rev RA
Section 2: Configuration
April 2015
Configuration
Figure 2-3. LOI Configuration Buttons
A. Configuration Buttons
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 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/dis-
abled by HART communication via a Field Communicator, AMS Device Manager, or the LOI.
LOI menu trees are available in Appendix A: Specifications and Reference Data .
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
Table 2-2. LOI Button Operation
Button
Left No SCROLL
Right Yes ENTER
A