Rosemount 5300 Series, Справочное руководство

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Analog-Input Block
May 2016
Reference Manual
00809-0100-4530, Rev DD
370
Analog-Input Block
I.6 Alarm Detection
A block alarm will be generated whenever the BLOCK_ERR has an error bit set. The types of
block error for the AI block are defined above.
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:
Table I-3. Alarm Level Priority
I.6.1 Status Handling
Normally, the status of the PV reflects the status of the measurement value, the operating
condition of the I/O card, and any active alarm condition. In Auto mode, OUT reflects the
value and status quality of the PV. In Man mode, the OUT status constant limit is set to
indicate that the value is a constant and the OUT status is
Good .
The Uncertain - EU range violation status is always set, and the PV status is set high- or
low-limited if the sensor limits for conversion are exceeded.
In the STATUS_OPTS parameter, you can select from the following options to control the
status handling:
BAD if Limited – sets the OUT status quality to Bad when the value is higher or lower than
the sensor limits.
Priority Number Priority Description
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.