Rosemount 6888Xi, Справочное руководство, Страница: 77 / 114

Configuration, Startup and Operation 69
Reference Manual Section 3: Configuration, Startup and Operation
00809-0100-4892 January 2019
tion was known to contain invalid values. Resetting a calibration will transfer the slope and con-
stant from calibration 1 in the log into the calibration 0 position. The cell impedance and days
since calibration remain unchanged.
Reset the calibration as follows:
Using the 6888Xi Keypad & Display: IOB 1 Probe 1(or 2)\Calibration\Cal Constants\
Current Cal\Reset Cal
Using the Field Communicator: Configure\Calibration\Calibration Constants\
Reset Calibration Constants
Follow the instructions on the screen to complete the reset function.
3.9 D/A Trim
The D/A trim procedure is used to calibrate the 4-20 mA output signal to a precision mA meas-
urement device. Only the signal to the DCS needs to be trimmed.
D/A Trim with 6888Xi
1. Press the MENU button repeatedly until the IOB1 Probe 1 menu displays.
2. From the main menu, select DIAGNOSTICS then press ENTER.
3. From the DIAGNOSTICS menu, select MAINTENANCE then press ENTER.
4. From the MAINTENANCE menu, select ANALOG OUTPUT then press ENTER.
5. From the ANALOG OUTPUT menu, select TRIM mA OUTPUT then press ENTER.
6. In the first screen, a “Remove Loop from Auto” warning occurs. Remove the 6888Xi from
any automatic controls loops to avoid a potentially dangerous operating condition. Press
FIGURE 3-8. D/A Trim Methods, Simplified
WARNING
Failure to remove the 6888Xi from automatic control loops prior to performing this procedure may result
in a dangerous operating condition.