Emerson Rosemount 3051S Series, Reference Manual, Page: 60 / 240

Reference Manual
00809-0100-4801, Rev FA
October 2010
Rosemount 3051S Series
3-18
DETAILED SETUP
Failure Mode Alarm and
Saturation
3051S transmitters automatically and continuously perform self-diagnostic
routines. If the self-diagnostic routines detect a failure, the transmitter drives
the output to configured alarm values. The transmitter will also drive the
output to configured saturation values if the applied pressure goes outside the
4-20 mA range values.
The transmitter will drive its output low or high based on the position of the
failure mode alarm jumper, see “Configure Security and Alarm” on page 2-13.
NOTE
The failure mode alarm direction can also be configured using the Field
Communicator or AMS.
3051S transmitters have three configurable options for failure mode alarm
and saturation levels:
• Rosemount (Standard), see Table 3-1.
• NAMUR, see Table 3-2.
• Custom, see Table 3-3.
Table 3-1. Rosemount
(Standard) Alarm and Saturation
Values
Table 3-2. NAMUR-Compliant
Alarm and Saturation Values
Table 3-3. Custom Alarm and
Saturation Values
Failure mode alarm and saturation levels can be configured using a Field
Communicator or AMS, see “Alarm and Saturation Level Configuration” on
page 3-19. Per Table 3-3, custom alarm and saturation levels can be
configured between 3.6 mA and 3.9 mA for low values and between 20.1 mA
and 23 mA for high values. The following limitations exist for custom levels:
• Low alarm level must be less than the low saturation level
• High alarm level must be higher than the high saturation level
• High saturation level must not exceed 21.5 mA
• Alarm and saturation levels must be separated by at least 0.1 mA
The Field Communicator or AMS will provide an error message if a
configuration rule is violated.
Level 4–20 mA Saturation 4–20 mA Alarm
Low 3.9 mA

3.75 mA
High 20.8 mA

21.75 mA
Level 4–20 mA Saturation 4–20 mA Alarm
Low 3.8 mA

3.6 mA
High 20.5 mA

22.5 mA
Level 4–20 mA Saturation 4–20 mA Alarm
Low 3.7 mA — 3.9 mA 3.4 mA — 3.8 mA
High 20.1 mA — 21.5 mA 20.2 mA — 23.0 mA