MAN0905_Issue 7_07/17
Searchpoint Optima Plus with optional HART
®
output
Operating Instructions
2108M0550
57
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.
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.
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.
12. Commissioning using
HART
®
Communications