Emerson Process Management MICRO MOTION 2400S - Manual (Page 52)

44 Micro Motion ® Model 2400S Transmitters for DeviceNet ™
Using the Transmitter
In addition, the transmitter maintains alarm history for the 50 most recent alarm occurrences. Alarm
history includes:
• The alarm code
• The “alarm active” timestamp
• The “alarm inactive” timestamp
• The “alarm acknowledged” timestamp
When the transmitter detects an alarm condition, it checks the severity level of the specific alarm and
performs the actions described in Table 7-6.
When the transmitter detects that the alarm condition has cleared:
• The first status flag is set to “inactive.”
• Digital communications fault action is deactivated (Fault alarms only).
• The “alarm inactive” record is written to alarm history (Fault and Informational alarms only).
• The second status flag is not changed.
Operator action is required to return the second status flag to “acknowledged.” Alarm
acknowledgment is not necessary. If the alarm is acknowledged, the “alarm acknowledged” record is
written to alarm history.
7.6.1 Using the display
The display shows information only about active Fault or Informational alarms, based on alarm status
bits. Ignore alarms are filtered out, and you cannot access alarm history via the display.
To view or acknowledge alarms using the display menus, see the flowchart in Figure 7-1.
If the transmitter does not have a display, or if operator access to the alarm menu is disabled (see
Section 8.9.3), alarms can be viewed and acknowledged using ProLink II or a DeviceNet tool. Alarm
acknowledgment is not required.
Additionally, the display may be configured to enable or disable the Ack All function. If disabled, the
Ack All screen is not displayed and alarms must be acknowledged individually.
Table 7-6 Transmitter responses to status alarms
Alarm severity
level
(1)
(1) See Section 8.8 for information on setting the alarm severity level.
Transmitter response
Status flags Alarm history
Digital communications
fault action
Fault • “Alarm active” status flag set
immediately
• “Alarm unacknowledged” status
flag set immediately
“Alarm active” record
written to alarm history
immediately Activated after configured fault
timeout has expired (if
applicable)
(2)
(2) See Sections 8.10.7 and 8.10.8 for more information on digital communications fault action and fault timeout.
Informational • “Alarm active” status flag set
immediately
• “Alarm unacknowledged” status
flag set immediately
“Alarm active” record
written to alarm history
immediately Not activated
Ignore • “Alarm active” status flag set
immediately
• “Alarm unacknowledged” status
flag set immediately
No action Not activated