Dwyer DPW - Manual (Page 11)

4.3.1.c - User Defined Unit Density Support Tabular entry
This function determines whether the newly entered user defined engineering unit
is a mass unit (with density) or a volumetric unit (without density). The following
selections are available: Enabled or Disabled. The default entry is Disabled.
The listed above density support selections can be set with the Up and Dn buttons
and are accepted by pressing ENT button. If density was selected, also refer to
section 4.9.8.
4.4 Submenu Flow Alarm
DPW provides the user with a flexible alarm/warning system that monitors the fluid
flow for conditions that fall outside configurable limits as well as visual feedback for
the user via the LCD (only for devices with LCD option) or via an optically isolated
outputs.
The flow alarm has several attributes which may be configured by the user via
optional LCD/keypad or digital communication interface. These attributes control
the conditions which cause the alarm to occur and to specify actions to be taken
when the flow rate is outside the specified conditions.
Flow alarm conditions become true when the current flow reading is equal or
higher/lower than corresponding values of high and low flow alarm levels. Alarm
action can be assigned with preset delay interval (0 to 3600 seconds) to activate
the optically isolated output (separate for high and low alarm). Latch mode control
feature allows each optical output to be latched on or follow the corresponding
alarm status.
4.4.1 Flow Alarm Mode Tabular Entry
This function determines whether flow alarm is Enabled or Disabled. The following
selections are available: Enabled or Disabled. The default entry is Disabled.
The listed above alarm mode selections can be set with the Up and Dn buttons and
are accepted by pressing ENT button.
4.4.2 - Low Flow Alarm Numerical Entry
The limit of required Low Flow Alarm value can be entered in increments of 0.1%
from 0 to 100% FS.
Note: The value of the Low Flow Alarm must be less than the value of the High
Flow Alarm.
A typical display with flow meter Low Flow Alarm is shown below.
If a Low Alarm occurs, and one of the two optical outputs is assigned to the Low
Alarm Event (see Section 4.8) the optically isolated output will be activated when
the flow is less than the Low Flow Alarm value. The Flow Alarm condition is also
indicated on the display Process Information Screen by displaying L character. A
typical display with flow meter Process Information Screen and activated Low Flow
Alarm is shown below.
4.4.3 - High Flow Alarm Numerical Entry
The limit of required High Flow Alarm value can be entered in increments of 0.1%
from 0 to 100% FS.
Note: The value of the High Flow Alarm must be more than the value of the Low
Flow Alarm.
A typical display with flow meter High Flow Alarm settings is shown below.
If a High Alarm occurs, and one of the two optical outputs is assigned to the High
Alarm Event (see Section 4.8) the optically isolated output will be activated when
the flow is more than the High Flow Alarm value. The Flow Alarm condition is also
indicated on the display Process Information Screen by displaying H character. A
typical display with flow meter Process Information Screen and activated High Flow
Alarm settings is shown below.
4.4.4 - Flow Alarm Action Delay Numerical Entry
The Flow Alarm Action Delay is a time in seconds that the Flow rate value must
remain above the high limit or below the low limit before an alarm condition is
indicated. Valid settings are in the range of 0 to 3600 seconds. A typical display with
flow meter Flow Alarm Delay settings is shown below.
4.4.5 - Flow Alarm Action Latch Tabular Entry
The Flow Alarm Action Latch settings controls Latch feature when optically isolated
outputs are assigned to Flow Alarm event. Following settings are available: Disable
or Enabled.
By default, flow alarm is non-latching. That means the alarm is indicated only while
the monitored flow value exceeds the specified set conditions. If optically isolated
output is assigned to the Flow Alarm event, in some cases, the Flow Alarm Latch
feature may be desirable.
The listed above Flow Alarm Action Latch selections can be set with the Up and Dn
buttons and are accepted by pressing ENT button.
4.5 - Submenu Temperature Alarm (*optional)
DPW with RTD option provides the user with a flexible alarm/warning system that
monitors the fluid temperature for conditions that fall outside configurable limits as
well as visual feedback for the user via the LCD (only for devices with LCD option)
or via an optically isolated outputs.
The temperature alarm has several attributes which may be configured by the user
via optional LCD/keypad or digital communication interface. These attributes
control the conditions which cause the alarm to occur and to specify actions to be
taken when the temperature value is outside the specified conditions. Temperature
Alarm conditions become true when the current temperature reading is equal or
higher/lower than corresponding values of high and low temperature alarm levels.
Alarm action can be assigned with preset delay interval (0 to 3600 seconds) to
activate the optically isolated output (separate for High and Low alarm). Latch
Mode control feature allows each optical output to be latched on or follow the
corresponding alarm status.
4.5.1 - Temperature Alarm Mode Tabular Entry
This function determines whether Temperature Alarm is Enabled or Disabled. The
following selections are available: Enabled or Disabled. The default entry is
Disabled.
The listed above Temperature Alarm Mode selections can be set with the Up and
Dn buttons and are accepted by pressing ENT button.
UDU Use Density
Disabled
Flow Alarm Mode
Disabled
Low Flow Alarm
10.0% FS
0.401 Gl/min AL
MT: 65.81 Gal
High Flow Alarm
90.0% FS
4.641 Gl/min AH
MT: 67.81 Gal
Flow Alarm Delay
1 Second
Flow Alarm Latch
Disabled
Temp Alarm Mode
Disabled
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