Answer / carl_ellis

What is Foundation Fieldbus LAS?

Link Active Scheduler (LAS)
A Link Active Scheduler (LAS) is a deterministic,
centralized bus scheduler that maintains a list of
transmission times for all data buffers in all devices that
need to be cyclically transmitted. Only one Link Master
(LM) device on an H1 fieldbus Link can be functioning as
that link's LAS.

The Master and Primary Backup Link Active Scheduler (LAS)
shall reside in the host control system in redundant H1
network interface cards.

An additional backup LM Link Master (B/U LAS Link Active
Scheduler) shall be configured for all networks and shall
reside in the network device with the lowest field node
address. The Backup LAS should be placed in a separate
device that does not have controlling functions.

Primary and secondary interfaces should sit in separate
backplanes with separate CPUs, preferably in separate
control panels. Similarly, the primary and secondary power
supplies should not share the same backplane. Having
redundant interface cards, CPUs, and power supplies in the
same backplane is self-defeating since the backplane is a
single point of failure.

Each network shall be configured for automatic fail-over to
the Back-up LAS in the event of Master LAS failure.

Carl Ellis
Measure First

How to consider the flow directions for control valve (Globe) Is the there any easy understanding in order to select the flow directions?

3 Answers  

---

what is function test.

1 Answers   Takreer,

---

Can any one send me IOCL instrumentation question papers.. i dont know the pattern of the questions and what to prepare can any one help me on this .. my email id is anwarnishil@gmail.com

0 Answers  

---

what will be the pressure in tank which has the total level of 2 meters and is filled 1.2 meters ?

4 Answers   Engro,

---

tell me the field & lab calibration procedure step by step with diagram of pressure gauge, pressure switch, pressure transmitter, temperature switch, level switch, flow switch, flow transmitter, temperature transmitter, temperature indicator, flow indicator, level indicator, control valve, thermocouple, pressure indicator (digital & analogue),

0 Answers  

---

---

compare the thermocouple and pyrometer,which one is the best?why?

4 Answers   Ramco,

---

An RTD is a_________________________.it works as follows

2 Answers  

---

What is mean by SMART in an Instrumentation. is any full form for SMART?

3 Answers  

---

how feedback signal frm rtd can be use for 2 purpose, i.e. 1for local monitoring and 2nd for controlling in dcs.so how many wired RTD can be used

1 Answers  

---

Any body have know try work calculation ???

0 Answers  

---

I need circuit for RTD senser?

0 Answers  

---

What is feedback system.

1 Answers   CCIE,

---