MEV Remote System update now available for Cyclone V

MEV have just released their MEV Remote System Update (MEV_RSU) technology for Altera Cyclone V family of FPGAs

Would you like to be able to update the logic inside Altera FPGA PCIe card design without having to return the device to the factory?

Would you like to be able to update your Altera FPGA PCIe card design without having to return the device to the factory?

Would you like this Remote Update solution to already have been done for you, leaving you only to worry about implementing your user logic?

MEV Remote System Update solution (MEV RSU) is a simple way to use Altera’s remote update system to deploy new solutions. You are probably using the Cyclone FPGA to implement your own PCIe card solution. This is likely to be a custom industrial solution which may need to be revised, upgraded and/ or bug fixed after the cards have been deployed. This normally means returning the card back to the factory to update its program via the programming header. MEV RSU means you or your end user can update the card firmware in situ without returning the card to base with simple to use tools.

For more information down load the MEVRSU data sheet or visit our web page www.mev.co.uk

ND Technology Data Cloud Solution Launched

NDT Technology Ltd rolled out their NDTDataCloud online data review and print application on 21/03/2014 developed and maintained by MEV Ltd
 

NDTDATACLOUD

On the road and need your rig data ? No problem.. By ND Technology Ltd

We are very pleased to announce the launch of our NDTDataCloud online data review & print application.

Supported by multiple operating systems and on multiple platforms, NDTDataCloud enables customers to access their rig data from any global location and on any web-browsing device within minutes of a pile’s completion.

Using technology to the full, the innovative NDTDataCloud application stores all rig data on an online server. This releases the tie from office based computers and third party software to offer customers the ultimate in flexibility and convenience.

The application leverages the existing code base developed for ND Technology’s legacy office data administration software. Hosted on a MS Windows Web Server with bespoke services to render images and PDFs, it provides client-ready reports meeting every requirement of the Institute of Civil Engineers.

 

ND Technology Piling Solutions

Recognition from ALTERA

On Wednesday, 28th January two MEV directors Helen Elcock and David Cooper, travelled to the Saville Court Hotel in Windsor to accept an award from ALTERA, for Outstanding Partner Support. During the presentation we were also singled out for our expertise in PCI express.

Naturally we at MEV Ltd, are both pleased and proud to have our work for ALTERA recognised in this way and we look forward to continuing to build upon a twenty two year strong relationship.

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When will RS485 become obsolete?

When designing controllers and monitoring systems for use in factories and other industrial locations or civil engineering projects there is often a need to communicate with the outside world in some manner. Even if the equipment normally operates autonomously it invariably needs some interface for set up and diagnostic functions.

So the question is. What is the most popular communication interface for designers of industrial electronic equipment?

Increasingly bulk communications are handled by Ethernet as more industrial locations are equipped with the cables and fibres but there are always going to be situations where ethernet is not practical. USB is suitable for short distances and compatible with lap top computers but will not work with distances over a couple of feet.

Step in RS485 . As the rugged brother of RS232, RS485 is simple, inexpensive to implement can handle a wide variety of protocols and can cover long distances. It is good for collecting data and remote control providing the data rates are not too large. It can plug into USB virtual serial ports on laptops via USB powered converters such as the USB485i

Using RS485 to link multiple devices in the field can be accomplished with multi-drop networks

All the embedded microcontroller systems and processor cards used in industrial designs incorporate standard serial ports so all the designer has to do is add an RS485 transceiver chip.

There are a few important things to consider when including an RS485 port in your design. Perhaps the two most important thing are the electrical environment in which the system is to operate and the distance the signals have to travel.

RS485 networks can be up to 1Km long so if the total network distance is over 1Km the network has to be separated into shorter lengths linked by repeaters such as the R485i. Longer distances are often linked to other problems. If the nodes are far apart they could also be susceptible to damage by electrical storms.

The designer needs to protect the device, and other components in the system, from damage by potential differences across the network caused by electrical storms or electrical faults. Lightning strikes can cause short but huge potential differences between network nodes causing equipment to see damaging voltages at its connections.

The size of the voltages seen depends on the proximity of the lightning strike to a network node and is a very interesting subject in itself but for now lets just say the closer the strike to a node then the bigger the voltage.

How do you protect against this? The first thing to do is to apply electrical isolation to the each node on the network. Opto-isolation is a common technique and is used in interface devices such as USB485i , PCI248H2i , and MEVs new PCI Express combined RS232 and RS485 card the PCIe249i. Optical isolation is good for about 1 kV of isolation. So if the lightning strike is not too severe then all is good. In many cases this sort of isolation is all that is needed to protect the network but there are some situations where it is not!

Cement works in the hills, steelworks in Yorkshire, engine plants and bridges linking countries have two things in common. The distances between nodes are physically large and they are all exposed to extreme weather. The very nature of their remoteness makes them susceptible to local lightning strikes as they are often the tallest things in the area.

MEV have twenty years of experience of solving RS485 communication problems and we have come across sites where extra protection is necessary. We have seen opto-isolaters blown to smithereens. In these installations we protect the network with our R485i RS485 repeater. The repeater extends the network distances and has opto-isolation but to the isolation we add a combination of transient absorbers and series protection elements to the RS485 lines. The Transorbs ( a type of fast zener diode) break down if the voltage exceeds a safe limit and the series elements, a type of PTC thermistor, act as resettable fuses becoming high impedance if excessive current flows, limiting the energy dissipated by the transorb and protecting it and the rest of the system from damage.

The high level of protection offered by this device means that we have never had a unit fail in the field and has led to the R485i being used in, the cement works, steelworks and bridges mentioned earlier, by Boeing on its production line,  in the O2 arena, Eden project and many other rugged locations.

So the answer to the question. ‘When will RS485 become obsolete?’ I think the answer is ‘Not in my lifetime’.

If you would like to know anything more about the issues here please contact Dave Cooper

 

Connecting PCI Express PCs to PLCs and other industrial i/o with the minimum of fuss

Let us say you have an application where the majority of the tasks are best suited to a PC but at the boundaries of the process you need to interface to real world signals, digital and analog.

You may need to monitor or activate 24v industrial  I/O signals to integrate PLC or other industrial control devices into your system.

Ok, so what are the options? You could set up a high level communications path from your PC to intelligence in a PLC based control system, passing messages back and forth, the PLC activating the plant signals.What if the task is simple? Perhaps you just want to activate a motor, set an alarm to a PLC. Then a high level protocol is expensive in terms of hardware and development resource.

What you really need is one or two plant level 24v inputs or outputs on your PC.

So how do you give your PC 24 volt I/O capability?

In the past many ways to do this have been developed. Traditionally PC plug in cards on ISA and PCI bus have been used. With modern PCs you have two realistic ways of connecting to it, either USB or PCI Express (PCIe). USB has advantages. You can use any PC, even a laptop but it is an extra box to be mounted with a connecting lead  and also the time latency associated with USB links may not be acceptable.

So what about PCIe?

A customer of Amplicon recently purchased a PCIe236 24 channel PCI express digital I/O card to interface to a Festo CMMS_ST stepper motor controller. The PCIe236 is an FPGA based PCI Express digital i/o board. Out of the bag it is capable of interfacing to 5v TTL inputs and outputs. It has special protection circuitry that allows it to accept inputs signals up to 48 volts without damage and with the addition of optional pull up resistors, that can be fitted in sockets on the card by the customer, it can drive digital outputs up to 48v.

The pull up resistor forms a potential divider with the input impedance of the external device and so limits the amount of current the PCIe236 can source to drive high voltage outputs . The voltage seen at the input of the external device (Vin) is therefore.

Vin = Vpu x Rin/(Rpu + Rin)

where:

Vpu = Pull up voltage, Rin = input resistance of device, Rpu = resistance of pull up resistor

The customer in question had to drive 24v signals to the Festo and receive 24v inputs from it. The Festo had an input impedance of 15k ohms and a minimum acceptable logic 1 input voltage of 15v. The customer found that using 4k7 pull up resistors on the PCI236 gave an adequate output high voltage over 16 volts.

Successful outcome and happy customer especially since the high voltage I/O capability meant the avoidance of costly extra circuitry and cabling.

Oh yes, and one more thing of interest perhaps! The PCIe236 is FPGA based and so it’s I/O pins can change function and direction without extra circuitry. This means the same physical hardware platform can be configured to do many different things by re-programming the FPGA and still interface to industrial I/O. But this is another story. For more info contact cooperd@mev.co.uk

Website news & events

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Welcome to our news and events section – from here on we will be posting company and industry news on a regular basis including news of exciting new products and forthcoming events.