Principle Of Operation - Emerson Fisher 4320 Instruction Manual

4320 Position Monitor
February 2013
Service Tools / Maintenance: Find
AMS Wireless Configurator or AMS Device Manager
Select Online, Service Tools, Maintenance, then Squawk from the Find tab to access Find with LCD, as shown in figure 28.
The squawk function displays the Emerson Logo steadily for 5 minutes on the local display of the device. You may
select how many time the squawk is repeated at 5 minutes per request. This function is not available if the local display
is too cold to work properly, or if the LCD screen is already being used locally by a technician. When the technician is
finished they can manually turn off the screen. If the screen is left unattended for 5 minutes it will turn off
automatically. Either of those cases will free the screen for use by the squawk feature.
If the unit has been located before the squawk counts have been exhausted, the function can be cancelled at the DD
screen. At the device's local screen, a technician can interrupt the Squawk logo display by pressing any button.
Figure 28. Find with LCD

Principle of Operation

The basic concept of the electronic positioner can be understood by visualizing a magnet mounted to a piece of
equipment that either has a rotating motion or sliding linear movement. The device has the ability to detect position
of the magnet and transmit wirelessly the relative position. The 4320 wireless position monitor is similar to a wired
position transmitter on a valve but without wires.
The 4320 is a communicating micro‐processor based instrument that includes the use of a Hall sensor to detect the
relative position (or percent of span) of a magnet that is attached to equipment (e.g. process control valve; either
automated or manual). The 4320 is a battery powered device with the power modules located on the inside of the
device. An optional external power option is also available. The primary means of communication is wireless,
conforming to the WirelessHART communications standards. The device also supports wired communication using the
HART protocol to connect to a handheld device, such as the 475 or 375 Field Communicator. The handheld
connection is used for initial device configuration (i.e. network set‐up). The device includes a local user interface (LCD
display and two pushbuttons) primarily used to calibrate or define the span of position being measured. No ground
point is required. The device contains an integrated omni‐directional antenna.
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Instruction Manual
D103392X012