Emerson Process Management 2400S 6 Transmitter responses to status alarms, 7.6.1Using the display

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.

Table 7-6Transmitter responses to status alarms

		Transmitter response
Alarm severity
			Digital communications
level(1)	Status flags	Alarm history	fault action
Fault	• “Alarm active” status flag set	“Alarm active” record	Activated after configured fault
	immediately	written to alarm history	timeout has expired (if
	• “Alarm unacknowledged” status	immediately	applicable)(2)
	flag set immediately
Informational	• “Alarm active” status flag set	“Alarm active” record	Not activated
	immediately	written to alarm history
	• “Alarm unacknowledged” status	immediately
	flag set immediately
Ignore	• “Alarm active” status flag set	No action	Not activated
	immediately

•“Alarm unacknowledged” status flag set immediately

(1)See Section 8.8 for information on setting the alarm severity level.

(2)See Sections 8.10.7 and 8.10.8 for more information on digital communications fault action and fault timeout.

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.

7.6.1Using 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.

44 Micro Motion® Model 2400S Transmitters for DeviceNet™