Answer / 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

pls tell me whethere flame proof HMI's are available or every HMI is manufactured by considering flame proof standard.

3 Answers  

---

how many maximum enter 2mm Dia solid cylindrical pipe into 8mm Dia hollow cylindrical pipe. give answer with calculation.

0 Answers  

---

What is the difference between EPROM & EEPROM.

1 Answers   Sabic,

---

Technician A says that a fuel tank sending unit will have a high resistance only when the tank is full. Technician B says that its resistance when the tank is full depends on whether the sending unit is designed for use with a bimetallic gauge or with a magnetic gauge. Who is correct?

3 Answers  

---

can i get any detail of interview question asked for instrumentation,plc,scada ,dcs..............

2 Answers   Asec, Honeywell,

---

What s PDS & PDMS tools ?its role in instrumentation?

1 Answers  

---

How a rtd work, and what volts/current goes to a RTD to measure the resistence?

1 Answers   DVC,

---

in which principle pressure tx,level tx ,flow tx,temp tx ,control valve works?

0 Answers   IOCL, JSW,

---

what is the procedure to callibrate temp controller ,pressure controller,etc. suppose a temp controller showing error 1.5 degree centigrate how can i minimize it.

0 Answers   Sabic, Saudi Aramco Shell Refinery Company SASREF,

---

What are securities of turbine?

1 Answers  

---

What is the use of the shield wire and how is the connection at both the ends of a shield wire?

2 Answers   Samsung,

---

what is the analog input , analog output , digital output, digital input geven to the MSSV , CBD, IBD , START UP VENT , BOILER FEED PUMP , AOP, CEP , ETC

1 Answers   Bharat Biotech, TATA,

---