Test 4-20 Ma Loop Integrity; Calibrate The 4-20 Ma Loop - Honeywell Searchpoint Optima Plus Operating Instructions Manual

MAN0905_Issue 7_07/17
12. Commissioning using

12.6 Test 4-20 mA Loop Integrity

It is recommended that the 4-20 mA loop integrity is tested by setting the Searchpoint Optima Plus to
output an overrange current. This will confirm that there are no faults in the system that would cause a
current limit.
Note: This function will timeout after 10 minutes of inactivity.
Note: When connecting or disconnecting a multimeter, power off the Searchpoint Optima Plus, otherwise
the unit will indicate a latched warning that the 4-20 mA loop was broken. If this occurs, it can be cleared
using the HART communications. See Clear Faults or Warnings.
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1. Select Device Setup.
2. Select Test
3. Select mA Loop Test
4. The display shows a warning message, press OK.
5. Select Other.
6. Input 21 and press Enter
Searchpoint Optima Plus will now output 21 mA.
7. Check that the signal at the controller is > 20 mA, then press OK
8. Select End.
9. The display shows a note that the Searchpoint Optima Plus will return to normal operation,
press OK.
10. The display shows a confirmation message, return to the Welcome screen.
Note: If the current at the controller is not correct, check the 4-20 mA loop connections and cabling, and
check that the loop resistance is less than 600 Ω. In current source mode, for supply voltages of 18 to
20 Vdc the maximum loop resistance is 500 Ω.

12.7 Calibrate the 4-20 mA Loop

If required, the 4 – 20 mA current output can be trimmed to match the controller. This is not a gas
calibration.
Note: When connecting or disconnecting a multimeter, power off the Searchpoint Optima Plus, otherwise
the unit will indicate a latched warning that the 4-20 mA loop was broken. If this occurs, it can be cleared
using the HART communications. See Clear Faults or Warnings.
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Note: If this process is aborted at any time, it may be necessary to wait 10 minutes before attempting the
calibration again. See Chapter 14, Troubleshooting.
HART Communications
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Searchpoint Optima Plus with optional HART
57
output
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Operating Instructions
2108M0550