ABB LLT100, Руководство по эксплуатации

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30 User Guide | OI-LLT100-EN Rev. D
LLT100
Laser level transmitter
10.3 Setting saturation limits
If the PV is below the lower range value (LRV), the signal is
driven to the “Low Saturation” limit. If the PV is above the
upper range value (URV), the signal is driven to the “High
Saturation” limit.
To set a saturation limit:
1. From the
Process Alarm
menu, select
Saturation Limits >
Low
(or
High
)
Saturation
.
2. In the resulting menu, edit the mA value and press OK .
10.4 Setting process alarms limits
In the Process Alarm Limits menu, you can configure the exact
value to which the signal can be driven.
To avoid problems, the “Low Alarm” value must be lower than
the “Low Saturation” limit, and the “High Alarm” value must be
higher than the “High Saturation” limit.
10.4.1 Setting current out alarms
The low alarm value range is between 3.6 mA and 3.8 mA
(default: 3.6 mA). The high alarm value range is between
20.5 mA and 22 mA (default: 21 mA). Current alarms are
alarms sent when the instrument itself has become unreliable
due, most of the time, to hardware failure.
To set the Current Out alarm limits:
1. From the
Process Alarm menu, select Process Alarm
Limits > Current Out > Low Alarm or High Alarm .
2. From there, edit the value as necessary, based on the
information above.
3. Press OK .
10.4.2 Setting level and ullage alarms
These alarms are only set for HART communication purposes.
To better understand the meaning of each alarm limit
(
Low Low, Low, High, High High
), see Figure 20 “Limits
variables diagram” on page 29.
To set a level or ullage alarm:
1. From the
Process Alarm menu, select Process Alarm
Limits > Level or UIlage and the alarm level that you want
to configure (Low Low, Low, High, High High).
2. Edit the level as necessary.
Figure 20 illustrates that the Low Low value must be lower
than the Low value, and that the High High value must be
higher than the High value. The LLT100 will not allow you to
enter values that do not meet this criteria.
10.4.3 Enabling level and ullage alarms
WIth the LLT100, you can define alarms and activate them
later on.
To do so:
1. From the
Process Alarm menu, select Process Alarm
Limits > Level or Ullage .
2. From the
Level
or
Ullage
menu, select
Enable
.
3. From the Enable menu, select Enabled and press OK .
10.5 Managing process alarms settings
Once you have completed setting up your process alarms, you
can save that setup or go back to factory settings if you prefer.
10.5.1 Saving settings as default
To save process alarms settings:
1. From the
Process alarm menu, select Settings > Save as
default.
2. From the Save as default screen, press OK .
The settings saved become the default configuration.
10.5.2 Resetting to default values
If you modified the process settings and realize that your
configuration should not be saved, it is possible to revert the
default display settings.
To revert to the default display settings:
1. From the
Process alarm
menu, select
Settings > Reset to
default.
2. From the Reset to default screen, press OK .
The settings go back to their default value.
10.5.3 Resetting to factory values
To revert to the process alarms settings that came with your
instrument directly from the factory:
1. From the
Process Alarm menu, select Settings > Reset to
factory.
2. From the Reset to factory screen, press OK .
The settings revert to the ones that came with the unit
directly from the factory.