Search results

The Siemens S7-400 series and S7-300 I/O racks are designed to operate together. For redundant operation, dual IM153-2 modules for Profibus operation are required in each S7-300 I/O rack to create a dual Profibus subnet.

I would be cautious about what is understood a passive and active. To me the passive isolator is active in that it "....filters and electrically isolates 0(4) 20 mA analog standard signals, while drawing power for signal transmission from the input circuit." So it is loop powered from source...

For S4-400 processors make that S7-400..

You haven't stated which type you have there since most 3500 series come as a single rack. I would guess you have a 3500 first rack with a 3300 2nd rack, with the system monitor interfacing the two.

Not sure what you mean by 'standard Siemens IO server software'. S4-400 processors are designed for large system / dual redundant applications and come with dual ethernet ports. So what you need depends upon configuration. For some Dual redundant applications Siemens Redconnect software is...

Most logic controllers do not have bridge rectifiers built into analog inputs, in fact most of us would recoil in horror as it introduces non-linear elements into circuit. However as the Microzone II is only to 10bit accuracy, HVAC designs here was never going to be precise. It appears to me...

You haven't described what you believe a 'scroll' to be. The scroll I have come across is metallic part of a larger machine within the gas industry. A metallic part of a larger machine is not a source of ignition, however could become one under hazardous conditions. There is no ATEX...

Quick Google search on this reveals little except your own posting! From your description it appears to bespoke control software. On a blind educated guess - are you familiar with 'C' (C++ or Lattice C) or similar? I do not consider these types of control software to be fail safe, so your...

You have not clarified but I'm guessing what you define as 'full connections' is 2 Modbus masters and 2 Modbus slaves on a single RS485 local network. If this is the case then you may have two masters attempting to take control of the 485 network. The probable result is that both may detect...

The best and most appropriate data should be obtained from the motor nameplate.

Simple - Ex'i' And if I were the end user/client I'd want evidence that the Ex'd' Certified transmitter was also Intrinsically Safe. Even though there is a barrier wired in doesn't necessarily mean the loop is safe.

I would suggest PID (proportional) loop in PLC control. I had a similar scheme except the setpoint was 'well level' rather than flow, however the principles are very close. If each pump speed was from two PLC analog o/p's, then a fine adjustment could be made to balance pump flows.

No - what type of License Agreement to you get?

I'd be bothered if any drawing numbers are as inconsistent as described. Every company I've worked with or for over the years has had different methods and the reasons for them. If it appears wrong, I'd ask why it is like it is.

I would not have a compressor controlled by DCS. A PLC is capable is acting within 20-30ms - faster if justified within it's design.

You need detailed knowledge of the process and what control functions it requires: - pumps - valves - temperature probes - operator controls A Process and Instrumentation Drawing is useful. Then work out what I/O you require. There used to be formulas for CPU type and memory but...

> Yes it does. OK. Why ?!

The Turbine designs I see, the external hardwired watchdog is combined with overspeed. So either overspeed detection or watchdog pulse which is one o/p from the PLC provides a hardwired monitor. If a PLC detected trip is required, the watchdog pulse simply stops which is a constant check on...

No it doesn't. Why do you ask. > is dedicated control system required for anti-surge control of compressor?

The basic answer is Yes. TIA stands for Totally Integrated Automation, which provides a working platform for both HMI and PLC application software including STEP7. I would recommend using V13 if you can.