Answer / carl_ellis

The Profibus DP specification defines the hardware transport
physical layer as 2 wire RS-485. The communications
protocol and the transport layer are both part of the
Profibus DP specification (the separate 2 wire cable for
24Vdc power supply is not involved with the communications).

Any device that passes Profibus DP certification will
conform to the Profibus DP specification.

Therefore, a 4 wire RS-485 device will not work on a
Profibus DP network because it won't be a Profibus DP
device, it does not meet the Profibus DP spec, which is 2
wire RS-485.

Attempting to operate a 4 wire RS-485 device on a Profibus
DP network will only disrupt Profibus DP communications on
the network.

Carl Ellis
Measure First

How to carry out hot loop checking of closed loop pf temperature control valve & temperature transmitter?

2 Answers  

---

I have transmitter of range -20 to -5 kpa.if it is possible to zero trim with atmospheric pressure,means HP and lp having no pressure...what will get after zero trim and it is the right way.....plz give me reply ....

3 Answers   KOC,

---

Types of contol loops

2 Answers  

---

What is voltage regulator?

0 Answers  

---

What is the procedure of changing a Faulty Module of Allen Bradley PlC without stopping the Process

1 Answers   Siemens,

---

---

Why Flow measure in Square-root?

12 Answers  

---

Whether the DI, DOs shields can be connected with Analog Input Shield Earthpit?

0 Answers  

---

how can i calibrate a smart temperature transmitter used by druck 720 process calibrator?

0 Answers   Texas,

---

how to tune the closed pid loop?

3 Answers  

---

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

0 Answers  

---

what are the possible reasons if a control valve fails to open/close?

1 Answers   DEWA,

---

Why the industry's standard current standards are from 4mA to 20mA,not from 0mA or any other range?

3 Answers  

---