Emerson Rosemount, Справочное руководство

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13
Reference Manual
00809-0100-4021, Rev GC
Section 2: Installation
April 2014
Installation
Write protect switch (HART and F
OUNDATION
fieldbus)
The transmitter is equipped with a write-protect switch that can be positioned to prevent
accidental or deliberate change of configuration data.
Alarm switch (HART)
An automatic diagnostic routine monitors the transmitter during normal operation. If the
diagnostic routine detects a sensor failure or an electronics failure, the transmitter goes into
alarm (high or low, depending on the position of the failure mode switch).
The analog alarm and saturation values used by the transmitter depend on whether it is
configured to standard or NAMUR-compliant operation. These values are also custom-configu-
rable in both the factory and the field using the HART Communications. The limits are:

21.0

I

23 for high alarm

3.5

I

3.75 for low alarm
Table 2-1. Values for standard and NAMUR operation
Simulate switch (F
OUNDATION
fieldbus)
Simulate switch is used to replace the channel value coming from the Sensor Transducer Block.
For testing purposes, it manually simulates the output of the Analog Input Block to a desired
value.
2.3 Mounting
If possible, the transmitter should be mounted at a high point in the conduit run so moisture
from the conduits will not drain into the housing. The terminal compartment could fill with
water if the transmitter is mounted at a low point in the conduit run. In some instances, the
installation of a poured conduit seal, such as the one pictured in
Figure 2-4 , is advisable. Remove
the terminal compartment cover periodically and inspect the transmitter for moisture and
corrosion.
Standard operation (factory default) NAMUR-compliant operation
Fail High 21.75 mA

I

23.0 mA Fail High 21 mA

I

23.0 mA
High Saturation I

20.5 mA High Saturation I

20.5 mA
Low Saturation I

3.90 mA Low Saturation I

3.8 mA
Fail Low I

3.75 mA Fail Low I

3.6 mA