Emerson Rosemount 6888A, Reference Manual

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3.9.4 Configure analog output
The analog output signal from the Rosemount 6888A can be configured for the 4-20 mA
range and fault condition. A separate configuration is set up when the Rosemount 6888A
is used with the optional Rosemount 6888Xi Advanced Electronics. When the Rosemount
6888A is used without the Rosemount 6888Xi, this parameter must be set to
NO
. If it is set
to YES and a Rosemount 6888Xi is not connected, the Rosemount 6888A triggers an alarm
and forces the analog output to the fault level. If the Rosemount 6888A is used later with a
Rosemount 6888Xi, the Rosemount 6888Xi automatically sets this parameter to
YES .
An Rosemount 6888A shipped from the output has the analog outputs set to 4 to 20 mA
range with a 3.5 mA alarm level. You must complete the same process any time
transmitter board is replaced.
1.
Use the 375/475 Field Communicator to access the main HART menu.
2. From the main menu, select CONFIGURE .
3. From the CONFIGURE menu, select MANUAL SETUP .
4. From the MANUAL SETUP menu, select
ANALOG OUTPUT
.
5. From the ANALOG OUTPUT menu, select from the following parameters; then press
ENTER.
• O
2
LRV: O
2
value at lower analog output value (0% at 4 mA, non-configurable)
• O
2
URV: O
2
value at upper analog output value (50% max at 20 mA)
• Output Range: Range of analog output (4-20 mA, non-configurable)
• Alarm level: O
2
alarm level (3.5 mA or 21.1 mA)
• Xi Mode: Selects whether or not the Rosemount 6888A is used with a Rosemount
6888Xi (should always be set to
NO for a stand-alone Rosemount 6888A)
6. Use the stylus to enter the value; then press ENTER when finished.
7. Use the stylus to select SEND to update the Rosemount 6888A.
3.10 Calibrate
New O
2
cells may operate for more than a year without requiring calibration, but older
cells may require calibration every few weeks as they near the end of their life.
A
CALIBRATION RECOMMENDED
alarm provides notice of when a calibration is required.
This strategy ensures that the O
2
reading is always accurate and eliminates many
unnecessary calibrations based on calendar days or weeks since previous calibration.
You can calibrate the Rosemount 6888A transmitter manually through the handheld
375/475 Field Communicator or the optional Rosemount 6888Xi. Fully automatic
calibration can be performed using the optional Rosemount 6888Xi advanced electronics
and the Rosemount SPS4001B Single Probe Autocalibration Sequencer or the Rosemount
IMPS 4000 Intelligent Multiprobe Sequencer.
Configuration, startup, and operation
Reference Manual 81