Emerson Rosemount, Справочное руководство

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93
Reference Manual
00809-0100-4021, Rev GC
Section 3: HART commissioning
April 2014
HART® commissioning
Figure 3-7. Change in Input versus Change in Output with Damping Enabled
3.8.3 Alarm and saturation
Field communicator
The Alarm/Saturation command allows the user to view the alarm settings (Hi or Low). This
command can change the alarm and saturation values. To change the alarm and saturation
values, select the value to be changed, either
1 Low Alarm , 2 High Alarm , 3 Low Sat , 4 High Sat, or
5 Preset Alarms and enter the desired new value which must fall within the guidelines below:

The low alarm value must be between 3.50 and 3.75 mA

The high alarm value must be between 21.0 and 23.0 mA
The low saturation level must be between the low alarm value plus 0.1 mA and 3.9 mA for the
standard HART transmitter. For the safety certified transmitter, the lowest saturation setting is
3.7 mA and the highest is 20.9 mA.
Example: The low alarm value has been set to 3.7 mA. Therefore, the low saturation level, S,
must be as follows: 3.8

S

3.9 mA.
The high saturation level must be between 20.5 mA and the high alarm value minus 0.1 mA for
the HART transmitter. The highest saturation setting for the transmitter is 20.9 mA.
Example: The high alarm value has been set to 20.8 mA. Therefore, the low saturation level, S,
must be as follows: 20.5

S

20.7 mA.
Preset alarms can either be 1Rosemount o r 2 NAMUR-compliant . Use the failure mode switch on
the front side of the electronics (see “Switch Location” on page 203 ) to set whether the output
will be driven to high or low alarm in the case of failure.
HART 5 Fast Keys
2, 2, 5, 6
HART 7 Fast Keys
2, 2, 5, 6
100.0
101.0
102.0
103.0
104.0
105.0
106.0
107.0
108.0
109.0
110.0
0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0 6.5 7.0 7.5 8.0 8.5 9.0 9.5 10.0
Input Value
Output Value
Time (Seconds)
Te
m
p
e
ra
tu
re