Emerson 4500 manual Digital-to-Analog Trim Using Other Scale

Models: 4500

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Reference Manual

00809-0100-4027, Rev AA December 2005

Rosemount 4500

AMS

Digital-to-Analog Trim Using Other Scale

Fast Keys

1, 2, 3, 2, 2

 

 

Right click on the device and select “Calibrate,” then “D/A Trim” from the menu.

1.Click Next after setting the control loop to manual.

2.Click Next after connecting the reference meter.

3.Click Next at the “Setting fld dev output to 4mA” screen.

4.Record the actual value from the reference meter, and enter it at the “Enter meter value” screen and click Next.

5.Select Yes, if the reference meter value equals the transmitter output value, or No if it does not. Click Next.

a.If Yes is selected, proceed to Step 6.

b.If No is selected, repeat Step 4.

6.Click Next at the “Setting fld dev output to 20mA” screen.

7.Repeat Step 4 - Step 5 until the reference meter equals the transmitter output value.

8.Select Next to acknowledge the loop can be returned to automatic control.

9.Select Finish to acknowledge the method is complete.

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 (for example, 1 to 5 volts if measuring across a 250 ohm load, or 0 to 100 percent if measuring from a Distributed Control System (DCS)). 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.

NOTE

Use a precision resistor for optimum accuracy. If you add a resistor to the loop, ensure that the power supply is sufficient to power the transmitter to a 20 mA output with additional loop resistance.

AMS

Right click on the device and select “Calibrate,” then “Scaled D/A trim” from the menu.

1.Click Next after setting the control loop to manual.

2.Select Change to change scale, click Next.

3.Enter Set scale-Lo output value, click Next.

4.Enter Set scale-Hi output value, click Next.

5.Click Next to proceed with Trim.

6.Click Next after connecting the reference meter.

7.Click Next at the “Setting fld dev output to 4 mA” screen.

8.Record the actual value from the reference meter, and enter it at the “Enter meter value” screen and click Next.

9.Select Yes, if the reference meter value equals the transmitter output value, or No if it does not. Click Next.

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Page 49
Image 49
Emerson 4500 manual Digital-to-Analog Trim Using Other Scale