Emerson 3051N 사용자 설명서

Reference Manual 

00809-0100-4808, Rev CA
June 2008

2-13

Rosemount 3051N

Transmitter Test

The transmitter Self Test command initiates a more extensive diagnostics 
routine than that performed continuously by the transmitter. The transmitter 
test routine can quickly identify potential electronics problems. If the 
transmitter test detects a problem, messages to indicate the source of the 
problem are displayed on the communicator screen.

Loop Test

The Loop Test command 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, perform the following procedure:

1.

Connect a reference meter to the transmitter. To do so, either connect 
the meter to the test terminals on the transmitter terminal block, or 
shunt the power to the transmitter through the meter at some point in 
the loop.

2.

From the 

 screen, select 1 Device Setup, 2 Diagnostics and 

Service, 2 Loop Test, to prepare to perform a loop test. 

3.

Select 

 after you set the control loop to manual (see “Setting the 

loop to Manual”). The communicator displays the loop test menu.

4.

Select a discreet milliamp level for the transmitter to output. At the 

 prompt, select 1 4mA, 2 20mA, or 

select 3 other to manually input a value. 

IF you are performing a loop 

test to verify the output of a transmitter, 

THEN enter a value between 

4 and 20 mA. 

IF you are performing a loop test to verify the 

transmitter alarm levels, 

THEN enter the milliamp value representing 

an alarm state (see Table 2-1).

5.

Check the electrical current meter installed in the test loop to verify 
that it reads the value you commanded the transmitter to output. 

IF 

the readings match, 

THEN the transmitter and the loop are 

configured and functioning properly. 

IF the readings do not match, 

THEN you may have the current meter attached to the wrong loop, 
there may be a fault in the wiring or elsewhere in the loop, the 
transmitter may require an output trim, or the electrical current meter 
may be malfunctioning.

After completing the test procedure, the display returns to the loop test screen 
and allows you to choose another output value or to exit loop testing.

NOTE
If the HART Communicator is disconnected from the process loop or loses 
power prior to exiting loop testing, output will remain fixed at the loop test 
value.

CALIBRATION

Calibrating a smart transmitter is different from calibrating an analog 
transmitter. The one-step calibration process of an analog transmitter is done 
in three steps with a smart transmitter:

•

—sets the 4 and 20 mA points at the desired pressures;

•

—Adjusts the position of the factory characterization curve 

to optimize the transmitter performance over a specified pressure 
range or to adjust for mounting effects

•

—Adjusts the analog output to match the plant 

standard or the control loop.

HART Comm.

1, 2, 1, 1

HART Comm.

1, 2, 2