Emerson Fisher FLOBOSS 407 Instruction Manual page 87

FloBoss 407 Instruction Manual
3.5.2.1 Check Current Loop Source Installations
Equipment Required:
1. Taking appropriate precautions, disconnect the field wiring going to the AO module terminations.
2. Connect a multimeter between the B and C terminals of the module and set the multimeter to
measure current in milliamps.
3. Using the ROCLINK software, put the AO point associated with the module under test in Manual
mode (scanning disabled).
4. Set the output to the high EU value.
5. Verify a 20-milliamp reading on the multimeter.
6. Calibrate the analog output high EU value as needed by increasing or decreasing the "Adj D/A
100% Units".
7. Set the output to the low EU value.
8. Verify a 4-milliamp reading on the multimeter.
9. Calibrate the analog output low EU value by increasing or decreasing the "Adj D/A 0% Units" as
needed.
10. Enable scanning for the AO point, remove the test equipment, and reconnect the field device.
11. If possible, verify the correct operation of the AO module by setting the high and low EU values as
before (scanning disabled) and observing the field device.
3.5.2.2 Check Voltage Source Installations
Equipment Required:
To check operation of the Analog Output module powering a voltage device, use the following
procedure.
1. If the resistance value (R) of the field device is known, measure the voltage drop (V)
across the device and calculate the output EU value using the following formula.
EU value = [((1000V/R - 4)/16) × Span] + Low Reading EU,
where Span = High Reading EU - Low Reading EU
2. Compare the computed value to the output EU value measured by the ROC/FloBoss with the
ROCLINK software. It is normal for the reading to be several percent off, depending on the
accuracy tolerance of the device and how rapidly changes occur in the output value.
3. Calibrate the analog output EU values by increasing or decreasing the "Adj D/A % Units" as
needed.
Rev 5/00
Multimeter
Personal Computer running ROCLINK Software
Multimeter
Personal Computer running ROCLINK Software
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