Diagnostics And Service; 1Performing A Loop Test; 2Simulate Digital Signal (Digital Loop Test) - Emerson Rosemount 644 HART Reference Manual

Reference Manual
00809-0100-4728, Rev MB
2.11

Diagnostics and service

2.11.1 Performing a loop test
The Analog Loop Test verifies the output of the transmitter, the integrity of the loop, and the operations
of any recorders or similar devices installed in the loop. To initiate a loop test, follow the steps below.
The host system may provide a current measurement for the 4-20 mA HART output. If not, connect a
reference meter to the transmitter by either connecting the meter to the test terminals on the terminal
block, or shunting transmitter power through the meter at some point in the loop.
Using a Field Communicator
From the HOME screen, enter the Fast Key sequence
Device Dashboard Fast Keys
Using AMS Device Manager
1. Right click on the device and select Service Tools.
2. In the left navigation pane choose Simulate.
3. On the Simulate Tab find the Perform Loop Test button in the Analog Output Verification group
box.
4. Follow the guided instructions and click Apply when complete.
Using Local Operator Interface
Reference the figure below to find the path to the Loop Test in the LOI menu.
Figure 2-20. Configuring the Tag with LOI
VIEW CONFIG
SENSOR CONFIG
UNITS
RERANGE
LOOP TEST LOOP TEST
DISPLAY
EXTENDED MENU
EXIT MENU
2.11.2 Simulate digital signal (Digital Loop Test)
The Simulate Digital Signal function adds to the analog loop test by confirming the HART output values
are outputting correctly. Digital Loop Test is only available in HART Revision 7 mode.
Using a Field Communicator
From the HOME screen, enter the Fast Key sequence
Device Dashboard Fast Keys
Configuration
SET 4 MA
SET 20 MA
SET CUSTOM
END LOOP TEST
BACK TO MENU
EXIT MENU
Configuration
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