Modes; Process Alarms; Alarm Priority - Emerson Rosemount 5900S Series Reference Manual

Rosemount 5900S Series

4.11.7 Modes

4.11.8 Process Alarms

4.11.9 Alarm Priority

Table 4-8. Alarm levels of
priority
4-46
The AI Function Block supports three modes of operation as defined by the
MODE_BLK parameter:
• Manual (Man) The block output (OUT) may be set manually
• Automatic (Auto) OUT reflects the analog input measurement or the
simulated value when simulation is enabled
• Out of Service (O/S) The block is not processed. FIELD_VAL and PV
are not updated and the OUT status is set to Bad: Out of Service. The
BLOCK_ERR parameter shows Out of Service. In this mode, you can
make changes to all configurable parameters. The target mode of a
block may be restricted to one or more of the supported modes.
Process Alarm detection is based on the OUT value. You can configure the
alarm limits of the following standard alarms:
• High (HI_LIM)
• High high (HI_HI_LIM)
• Low (LO_LIM)
• Low low (LO_LO_LIM)
In order to avoid alarm chattering when the variable is oscillating around the
alarm limit, an alarm hysteresis in percent of the PV span can be set using the
ALARM_HYS parameter.
The priority of each alarm is set in the following parameters:
• HI_PRI
• HI_HI_PRI
• LO_PRI
• LO_LO_PRI
Alarms are grouped into five levels of priority:
Priority Number
0 The priority of an alarm condition changes to 0 after the condition that
caused the alarm is corrected.
1 An alarm condition with a priority of 1 is recognized by the system, but is
not reported to the operator.
2 An alarm condition with a priority of 2 is reported to the operator, but does
not require operator attention (such as diagnostics and system alerts).
3-7 Alarm conditions of priority 3 to 7 are advisory alarms of increasing priority.
8-15 Alarm conditions of priority 8 to 15 are critical alarms of increasing priority.
Reference Manual
00809-0100-5900, Rev CA
Priority Description
Section 4. Configuration
June 2014