Emerson 3051N manual Recall Factory Trim— Sensor Trim, Recall Factory Trim— Analog Output

Reference Manual

00809-0100-4808, Rev CA June 2008

Rosemount 3051N

Recall Factory Trim

Recall Factory Trim— Sensor Trim

HART Comm. 1, 2, 3, 4, 1

Recall Factory Trim— Analog Output

HART Comm. 1, 2, 3, 4, 2

Analog Output Trim

The Recall Factory Trim commands allow the restoration of the as-shipped factory settings of the sensor trim and analog output trim.

Resets the transmitter sensor trim to the as-shipped factory settings. The Recall Factory Trim—Sensor Trim command can be useful for recovering from an inadvertent zero trim of an absolute pressure unit.

Resets the transmitter analog output trim to the as-shipped

factory settings. The Recall Factory Trim—Analog Output Trim command can be useful for recovering from an inadvertent zero trim on an absolute pressure transmitter.

The Analog Output Trim commands allow you to adjust the transmitter’s current output at the 4 and 20 mA points to match the plant standards. This command adjusts the digital to analog signal conversion (see Figure 2-7).

Digital-to-Analog Trim

HART Comm. 1, 2, 3, 2, 1

Digital-to-Analog Trim Using Other Scale

HART Comm. 1, 2, 3, 2, 2

To perform a digital-to-analog trim with a HART Communicator, perform the following procedure.

1.From the ONLINE screen, select 1 Device setup, 2 Diag/Service,

3 Calibration, 2 Trim Analog Output, 1 Digital-to-Analog Trim. Select

OK after you set the control loop to manual (see “Setting the Loop to Manual” on page 2-5).

2.Connect an accurate reference ammeter to the transmitter at the CONNECT REFERENCE METER prompt. To do so, connect the positive lead to the positive terminal and the negative lead to the test terminal in the transmitter terminal compartment, or shunt the transmitter power through the reference meter at some point.

3.Select OK after connecting the reference meter.

4.Select OK at the SETTING FLD DEV OUTPUT TO 4 MA prompt. The transmitter outputs 4.00 mA.

5.Record the actual value from the reference meter, and enter it at the ENTER METER VALUE prompt. The communicator prompts you to verify whether or not the output value equals the value on the reference meter.

6.Select 1 Yes if the reference meter value equals the transmitter output value, or 2 No if it does not.

IF you select 1 Yes, THEN proceed to Step 7. IF you select 2 No, THEN repeat Step 5.

7.Select OK at the SETTING FLD DEV OUTPUT TO 20 MA prompt, and repeat Steps 5 and 6 until the reference meter value equals the transmitter output value.

8.Select OK after you return the control loop to automatic control.

The Scaled D/A Trim command matches the 4 and 20 mA points to a user-selectable reference scale other than 4 and 20 mA (1 to 5 volts if measuring across a 250 ohm load, or 0 to 100 percent if measuring from a DCS, for example). To perform a scaled D/A trim, connect an accurate reference meter to the transmitter and trim the output signal to scale as outlined in the Output Trim procedure.

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