L-737-3-E
73
9.16 High/Low Alarm Function
The transmitter provides the operator with quick grasp of conditions of the installation
-
flowrate,
temperature, density and total flow
-
when high/low alarms are set up. In the event the preset alarm
conditions are met, it tells the operator the event with an alarm message along with a status output signal.
Setup procedure and behavior of alarm functions are described below:
() Setup procedure
Ensure positive settings on individual items.
①
Status output function assignment (Function) (See .. Transition chart () [No. ---].)
To use high/low alarm function, it is essential to assign high/low alarms to status output.
Set "H/L Alarm" to status output function assignment.
("H/L Alarm" setting is required even in cases of high alarm only or low alarm only.)
②
Output mode of status output (Mode) (See .. Transition chart () [No. ---3].)
Set up the output mode of status output.
・
Active output of status output: Off Active or On Active
(For detail of the status output function, see . Status Output Function.)
③
Assignment of H/L alarm values (Assign) (See .. Transition chart () [No. --].)
From the following options, select the variables against which the transmitter identifies
alarmed conditions.
・
Mass Flow: Instant mass flowrate
・
Vol Flow: Instant volume flowrate
・
Dens:
Density
・
Temp:
Temperature
・
Counter : Counter
・
Counter : Counter
④
Alarm type selection (H/L Alm. Type) (See .. Transition chart () [No. --].)
Select alarm type from the following options.
・
To validate only high alarm, select "High Alarm".
・
To validate only low alarm, select "Low Alarm".
・
To validate both high and low alarms, select t "H/L Alarm".
⑤
High alarm value setting (High Alm. Po.) (See .. Transition chart () [No. --3].)
If the input exceeds this setting, the high alarm is activated. Set the high alarm value
desired.
In the case "Low Alarm" is set in
④
, setting is not required.
⑥
Low alarm value setting (Low Alm. Po.) (See .. Transition chart () [No. --].)
・
Low Alm. Po.: Low alarm value
In the case "High Alarm" is set in
④
, setting is not required.
⑦
Hysteresis value setting for high/low alarms (H/L Alm. hys)
(See .. Transition chart () [No. --].)
The setting determines a dead (or immunity) zone following the occurrence of an alarm.
Select a larger value when measurement fluctuates excessively; select a smaller value if
fast recovery from alarmed condition is desired.
NOTE: For this function, the setting change is disabled
in Write Protect mode (refer to section .).