
79
Reference Manual
00809-0100-4001, Rev JA
Section 4: Operation and Maintenance
November 2012
Operation and maintenance
AMS Device Manager
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 4 mA (1 Vdc) 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 20 mA (5 Vdc) 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.
4.4.2 Digital-to-Analog trim using other scale
The Scaled D/A Trim command matches the 4 and 20 mA (1 and 5 Vdc) points to a user
selectable reference scale other than 4 and 20 mA (for example, 2 to 10 volts if measuring across
a 500 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. Refer to “Power supply for 4-20 mA HART” on page 25.
Field communicator
Traditional 4-20 mA Fast Keys
1, 2, 3, 2, 2
Traditional 1-5 Vdc Fast Keys
1, 2, 3, 2, 2
Device Dashboard Fast Keys
3, 4, 2
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