Interested to Buy Any Domain ? << Click Here >> for more details...
There is a problem with our HART475 it is not communicating
with smart devices error becomes "NO DEVICE FOUND"we have
insert 250ohm resistance as per requirement but invain plz
tell me the solution?
- 1 Answers
- 6966 Views
- I also Faced
- E-Mail Answers
Answer Posted / carl_ellis
1) How do you know that the device talks HART? Many field transmitters talk Brain, Honeywell DE, Foundation Fieldbus, Profibus or 4-20mA only.
Have you confirmed the HART functionality on that device?
2) Point-to-point (communicator-to-transmitter) is usually done with the device at address 0 and with the communicator polling address 0.
Is the communicator polling address 0?
Is the device at address 0?
3) On many transmitters, HART can be disabled. Is HART enabled on this transmitter?
4) The transmitter has to be powered, initialized and in its operating mode in order to communicate via HART. Sometimes transmitters are not powered, but when connecting from the a marshalling panel, it is obvious, because the transmitter is remote location. Is the transmitter powered and operating?
5) Are connections across the dropping resistor or across the transmitter's (+) or (-) terminals? Connecting across a pressure transmitter's 'test' terminals will not work properly for HART communication.
6) A loop isolator module that is not specifically designed for HART will strip off the HART signal, but pass the 4-20mA current signal. If a loop isolator is installed in the loop, is it designed for HART operation.
7) If the power supply ripple and noise exceeds the HART specification, the power supply noise will interfere with HART or prevent communication entirely.
8) The 475 can have 3 terminals at the top where the banana plug field cable plugs in. 2 terminals are for HART, 2 terminals are for Foundation Fieldbus (FF). If the cable is plugged into the 2 terminals for FF, HART communications will be blocked by not having a cable in the correct port.
Carl Ellis
Measure First
| Is This Answer Correct ? | 1 Yes | 0 No |
Post New Answer View All Answers
1.can you use SCADA instead of DCS,DCS instead SCADA 2.Difference between DCS and PLC,can their role be reversed i.e. role interchange 3.Difference between RTU and PLC
Why boiler chimney area oxyden sensor fixing?
Calibration procedure for Electro magnetic Flow meter
what is different between 2,3&4 wire rtd and how much maximum distance using plc to field.
please send me the inteview questions in IOCL
what is difference between HOT permit and cold permit
What is shielding effect?
How do bending tubing provide better measurement than using tubing fittings such as elbows?
Linear amplifier.
sir ,iam in dem urgent need of HPCL Paper of Instrumentation Branch plz send me at your earliest convenience at ujjwal_sharma1983@yahoo.com
What is difference between “Fault Tolerant” & “Fault avoidance” PLC? Application where these system s are used?
How can measure flow in oil line?which type of transmitter is generally used?
why would you like to join our company
What is intrinsic safety mean.
What is modbus?
