User`s manual

74 Chapter 7 535 User's Manual
Applications
ACK.:1 and ACK.:2
For any enabled alarm, enables or disables operator use of the ACK
key to acknowledge an alarm at any time, even if the control process is
still in the alarm condition.
A latching alarm can always be acknowledged when it is out of the alarm
condition. When either alarm is available to be acknowledged, the ACK
key will be illuminated. If both alarms are acknowledgeable, pressing
ACK will first acknowledge alarm #1. Pressing ACK a second time will
acknowledge alarm #2.
POWER UP:1 and POWER UP:2
For any enabled alarm, selects the alarm condition upon power up.
Choices are:
• NORMAL
Controller will power up in alarm only if it is in alarm condition.
• ALARM:
Controller always powers up in alarm regardless of system’s alarm
condition. This is an excellent way to activate an alarm if there has
been a power failure.
• DELAYED
Controller will never power up in alarm, regardless of system’s alarm
condition. The system must leave and reenter the alarm condition
before the alarm will activate. This is typically used to avoid alarms
during start up.
MESSAGE:1 and MESSAGE:2
Allows user to specify a nine-character message to be displayed when
the respective alarm is active. If both alarms are active or any other
diagnostic message is present, the messages will alternate.
FAULT
Activates an alarm if the process variable signal is lost. Assign this func-
tion to either Alarm 1 or Alarm 2 (not both). This action is in addition to
the selected alarm type (additive alarm function).
OUTPUT
For a RATE alarm, selects the output action. Use to obtain early indica-
tion of a possible break in the process variable signal. Select PV BREAK
to have rate-of-change alarm take the same action as a detection of a
break in the process variable signal (where it trips to manual control at
a predetermined output).
RATE TIME
For RATE alarms, defines the time period over which a discrete change
in process variable must occur for the rate alarm to be activated. The
amount of change is defined by the alarm setpoint. The rate-of-change
is defined as the amount of change divided by the time period.
Example
A. If the alarm setpoint is set to 10 and the time base is set to 1 second,
the rate of change is 10 units per second.
B. If the alarm setpoint is set to 100 and the time base set to 10, the rate
of change is also 10 units per second.
Alarm Parameters Reference
For Alarm 1
Parameter Description
ALM. TYPE:1 Type
ALM. SRC.:1 Source
ALARM SP:1 Setpoint
HIGH SP:1 High setpoint
LOW SP:1 Low setpoint
DEADBAND:1 Deadband
ALM.:1 OUT. Output number
LATCHING:1 Latching sequence
ACK.:1 Acknowledging
POWER UP:1 Status on power up
MESSAGE:1 Message
For Alarm 2
Parameter Description
ALM. TYPE:2 Type
ALM. SRC.:2 Source
ALARM SP:2 Setpoint
HIGH SP:2 High setpoint
LOW SP:2 Low setpoint
DEADBAND:2 Deadband
ALM.:2 OUT. Output number
LATCHING:2 Latching sequence
ACK.:2 Acknowledging
POWER UP:2 Status on power up
MESSAGE:2 Message
For either alarm
(depending on choices)
Parameter Description
FAULT Fault assignment
OUTPUT Output action for rate
RATE TIME Time base for rate