Emerson 3051N manual Transmitter Test, Loop Test, Calibration

Reference Manual

00809-0100-4808, Rev CA June 2008

Rosemount 3051N

Transmitter Test

HART Comm. 1, 2, 1, 1

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

HART Comm. 1, 2, 2

CALIBRATION

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 ONLINE screen, select 1 Device Setup, 2 Diagnostics and Service, 2 Loop Test, to prepare to perform a loop test.

3.Select OK 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

CHOOSE ANALOG OUTPUT 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.

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:

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

•Sensor Trim—Adjusts the position of the factory characterization curve to optimize the transmitter performance over a specified pressure range or to adjust for mounting effects

•Analog Output Trim—Adjusts the analog output to match the plant standard or the control loop.

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