Honeywell Searchpoint Optima Plus - 5. Operation; 5.1 Default Configuration; 5.2 HART Operation during Fault

MAN0905_Issue 7_07/17 Searchpoint Optima Plus with optional HART
®
output
Operating Instructions
2108M0550
30
5. Operation
During normal operation, the 4-20 mA output represents 0-100 %FSD. The output is linear.
Analogue output below 4 mA represents diagnostic information. If the Searchpoint Optima Plus measures
a negative gas reading, the analogue output will remain at 4 mA until the negative gas warning threshold
is reached (-3 %FSD to -6 %FSD depending on the gas being measured) at which point it will signal a
Warning.
5.1 Default Conguration
Status Current output
Fault < 1 mA
Warning 3 mA
Gas Reading 4 – 20 mA
Overrange 21 mA
Inhibit 2 mA
The tolerance on the nominal current output value is ± 0.2 mA.
During Warning status, the Searchpoint Optima Plus will continue to monitor gas, and will revert to Gas
Reading status if a gas reading is detected.
If a Warning is indicated, schedule maintenance to investigate and rectify the cause. If left unattended, the
unitislikelytoenterFaultstatus,whenitwillbeofine.
TheWarning,InhibitandOverrangesignallevelscanbeconguredusingtheHART
®
communications, or by
aHoneywellAnalyticsFieldServiceEngineerasfollows:-
Parameter Range
Warning* 0 mA to 6 mA
Inhibit 1 mA to 3 mA
Overrange 20 mA to 21.6 mA
* For ATEX compliance, the warning value should not be set > 3 and < 5 mA. If the warning value is set
higher than 4 mA, the output signal will toggle between the warning value for 1 s and the current gas
reading for 9 s.
5.2 HART
®
Operation during Fault
HART
®
communicationrequires>1mAcurrentoutputfortransmission,thereforeiftheHART
®
version of
theSearchpointOptimaPlusgoesintoFaulttheHART
®
communications will not work.
ItispossibletoconguretheFaultoutputlevelofaSearchpointOptimaPlusunitwithHART
®
to be 1 mA.
Thiscanbedoneduringcommissioning(seeCommissioningusingHART
®
Communications,Congure
HART
®
Operation during Fault).