Industrial Data Xchange

HDLC to PROFIBUS Gateway

2011-10-11T02:06:00.000-07:00

The integration of legacy systems and modern technology is sometimes a challenge in the creation and maintenance of robust industrial environments. The maintenance cost and shortage of spare parts for old equipment creates a financial burden and production risk that raises questions - is there a better way, can we leverage the cost and energy efficiency benefits of newer technology?

In response to a customer requirement to retain his existing PLC (with unmodified code) but over time migrate legacy drives to modern drives we have created a gateway/converter that allows them the freedom to upgrade equipment incrementally. In their case a number of drives are controlled over a multi-drop RS485 network using the GEM80 Starnet HDLC protocol.

Our gateway provides access to the original HDLC network and also to a parallel PROFIBUS network. It is possible to disconnect a legacy HDLC controlled drive and enable a modern replacement drive on the PROFIBUS network - the PLC is not aware that anything has changed - our gateway does the necessary data mapping and error management.

Our gateway is generic and can be extended to handle similar requirements with other leagacy and modern fieldbus or industrial ethernet standards.

Below is an indication as to the integration you are now able to create with your legacy HDLC PLC network.

As you can see from the image above we have replaced the legacy drive 1 and 4 with modern PROFIBUS drives which are able to run in parallel with legacy drive 2 and 3. As far as the PLC is concerned it is still talking to a legacy drive on address 1 and 4, but the HDLC gateway is doing all the conversion necessary to control the PROFIBUS devices.

For more details contact us at info@idxonline.com

IDX Breakfast 2011

2011-10-10T06:56:00.001-07:00

IDX hosted a breakfast at Blandford Manor, Johannesburg, on Wednesday 7^th September. The presenter was Dennis Van Booma, General Manager of PROCENTEC and Chairman Working Group “Training” at PROFIBUS International. The company PROCENTEC, based in The Netherlands, concentrates all products and services on the PROFIBUS and PROFINET technology. The first presentation gave insight into COMbricks from PROCENTEC, the first PROFIBUS and PROFINET based automation system that unites network components, permanent monitoring with ProfiTrace and remote I/O. The second presentation was about PROFINET. IDX is a PROFIBUS Competence Centre in South Africa and is a gold distributor for PROCENTEC.

HDLC GEM80-400 converter

2011-10-10T03:38:00.000-07:00

We have recently designed a gateway for one of our clients that allows them to use their old GEM80-400 PLC to control PROFIBUS devices. Their upgrade procedure requires the old system running in parallel with the new system so they needed a gateway that was completely transparent to the old GEM80-400 PLC. The gateway transparently connects the old technology with the new, allowing for the easy integration of modern technology.

Looking at the requirements that our clients had we realized that the system needed to be robust and versatile, allowing for the integration of a vast array of modern technologies. Leveraging the versatility of the converters and gateways already developed, we have built on the technology that is already tried and tested, and developing only what was not already available.

With current testing and design we have developed a Modbus TCP driver which allows us to control most devices and connect to the majority of gateways already available. This allows for easy proof of concept allowing for the design of specific drivers if required.

Getting the GEM80-400 PLC protocol structure (starnet HDLC operating at 180000bps over 4 wire RS485) translated into Modbus TCP has enabled us to provide upgrade strategies to our clients who have to approach their PLC and system upgrades incrementally, which previously was not possible.

Below are a few examples of what systems our clients would be able to integrate with:

HDLC to PROFIBUS
HDLC to PROFINET
HDLC to EtherCAT
HDLC to Modbus TCP
HDLC to ControlNet
HDLC to DeviceNet
HDLC to ASi
HDLC to Ethernet/IP

We see the development of this device changing the way people perceive technology and re-evaluating the strategies they need to employ when upgrading their site infrastructure. Africa has a lot of legacy systems which inevitably will require upgrading. We believe we have created a system that makes that transition a whole lot easier.

Feel free to contact us at info@idxonline.com for any questions you may have.

PROFIBUS Training Courses in Richards Bay

2011-10-07T03:00:00.000-07:00

The PROFIBUS Competence Centre (PCC) travelled down to Richards Bay in September to give two consecutive Troubleshooting and Maintenance courses at Mondi. This training was organised by Cube Technologies who has partnered with the PCC to facilitate Profibus Training in KwaZulu-Natal.

The course was well received with 15 new PROFIBSUS Installers becoming certified. The attendees had the opportunity to do some hands-on troubleshooting on the PCC’s training rigs. They are asked to identify and correct the faults on the rigs which are typical faults that one might find on a plant. Some of these faults can be identified and corrected by visual inspection, which can only be done once you know what you are looking for – that is, by coming on training. Some faults you can only identify with the appropriate test tools, without which, they discovered, they would be shooting in the dark. Profibus test tools include the BC-600 from Softing, the NETTEST II from COMSOFT and the ProfiCore Ultra from PROCENTEC.

The training the PCC offers has to keep up-to-date with the latest technologies that are at the PROFIBUS user’s disposal. This is why ComBricks from PROCENTEC have been introduced into the troubleshooting section of this course. ComBricks allows for permanent remote monitoring of your PROFIBUS or PROFINET network and can be used a modular repeater. ComBricks are able to record messages from before and after an error occurs and email the appropriate personnel of an alarm or a potential problem. A user can log in through a web browser, potentially from home though VPN and monitor the network in real time and advise on-site personnel on what to do. For those attendees that are on standby, this is a very appealing product!

All of these devices and test tools are available from IDX.

Thank you to Dianne Williams from Cube Technologies for organising the training and to Sharmaine Dyman, The HR Coordinator for Training at Mondi who made sure that everything ran smoothly. We look forward to running training in Richards Bay soon again.

If you are in the Natal region and would like to attend a PROFIBUS Course and not have to travel to Johannesburg to do so, then Contact Dianne Williams at Cube Technologies on +27 31 764 6081 or visit their site at www.cubetech.co.za. For training in Johannesburg or on-site training, then please feel free to contact the PCC on +27 11 548 9977 or visit www.profibuscentre.co.za.

Gold Certified Partner

2011-10-07T02:04:00.000-07:00

IDX recently attained the Gold certified status from PROCENTEC. So many of you may think “what does this mean?”. PROCENTEC is rewarding companies for attaining a level of excellence by auditing their distributors according to a variety of standards that they have felt is important. These standards include, the technical knowledge of their devices, the practical capability to be able to setup these devices correctly, the CRM system that is used by the company must contain detailed information about the clients and the quotes and invoices. So we can make sure you get the correct device you ordered on time.

What was probably the most interesting part is that we had to write a test, there were 2 options for this test. Either you could write it on an individual basis and you must pass by 90% or you can write the test as a group effort but the trick is that you must get 100% to pass. So you can guess what we did…that’s correct, we opted for the group effort and we passed. It was even fun on top of that.

If you become Gold certified there are 2 things that are very important: you must attend at least 1 distributor conference and all the gold certified companies are the first to get the latest demo items available.

What does this mean for you? We know what we are talking about, we are organized, we have the latest devices PROCENTEC has to offer for you to come see and test.

KNX Training

2011-10-07T00:41:00.000-07:00

We have been hard at work on our newest IDX Academy offering. Our strong industrial networking background has provided a great base to launch into the building automation space.*The KNX training course is offered at two levels, namely basic and advanced. The basic course will leave delegates with a solid detailed understanding of how KNX works, practical experience in setting up and configuring devices using ETS™, and how to design and specify a KNX system. You will also learn important techniques for energy saving and how to best go about specifying devices to minimise energy costs.

The advanced course builds on knowledge offered in the basic course, and offers users in-depth knowledge of building automation systems, such as heating, lighting and air conditioning as well as an in depth look into the KNX protocol. The advanced practical includes topics such as security and motor control.*Delegates leave the training courses feeling confident in their knowledge to be able to tackle the world of building automation.

In order to ensure that delegates across the globe receive the same quality of training, the KNX association requires, in addition to the trainer having a KNX tutor’s qualification, that the training centre is audited to ensure that the material and training rigs used are of a satisfactory standard.

IDX is excited to be getting audited at the end of October 2011, at which time we will be able to provide certified KNX training. We are also preparing to complete the KNX tutor’s qualification at the same time.

A huuuuuuge thanks to ABB for all their support and generosity in donating equipment for training!!!

We hope to see you soon!

Anybus Wireless Bridge

2011-10-06T23:47:00.000-07:00

I have often been asked if there is a possibility to convert from Modbus to Ethernet and then back to Ethernet, in other words the information needs to be bridged across an Ethernet infrastructure. Anybus is now meeting these requirements using wireless technology with a clever and robust solution.

How it works

The wireless modules act as a wireless bridge where a physical cable would usually be installed. What makes this wireless module so impressive is its ease of use. The simplest configuration is a point to point connection.

The wireless modules require relative little configuration which is all done via the buttons on the modules. The modules will scan for the device that it is connected to and learn the MAC address (physical address) and IP address of the device. Both modules will need to learn the device that they are connected to, from there it is just plug and play. Since the module take on the IP of the device that it is connected to, the modules appear completely transparent hence no changes to your system.

This isn’t the only topology configuration that you can select but it is the easiest. The modules have a built in web server to configure more advanced stings and this allows you to connect to existing wireless networks.

Device features

The wireless modules support 802.11 b/g and 2.4 GHz and 5GHz versions. The modules have a built in antenna with a half radio globe coverage, this is used to concentrate the signal giving the devices better range. The modules are also IP 65 rated and are perfect for industrial applications and are hopefully Africa proof.

The only negative aspect to the product is that the Ethernet connection and the power are connected using M12 connectors making setup take a little longer but this will definitely make them more weather resistant in the long run. The wireless range is up to 400m.

IDX introduces AS-Interface (ASi) training

2011-06-17T06:46:00.000-07:00

IDX has been successfully running certified PROFIBUS training for the last half decade and is now starting the IDX Training Academy which will be the umbrella for other fieldbus and device training. Watch this space for future training offerings including PROFINET, MODBUS and device related training (HMS, Procentec, Softing and Comsoft). We have been providing a combined PROFIBUS/ASi course for a number of years but we have decided to give ASi a space of its own. So we are proud to introduce Actuator/Sensor Interface, otherwise known as AS-Interface (ASi), training.

The course will begin with an introduction to AS-Interface: where does it fit and when to choose it. Attendees will have a look at various topology options and network structures. The course then covers how power and data are transmitted and how the masters and slaves interact with each other. The training will cover the features, benefits and limitations of ASi as well as some safety considerations. The attendees will discover how ASi can be incorporated into higher-level network structures such as PROFIBUS.

The attendees will investigate how ASi handles data throughput in terms of speed, delay times, jitter etc. The course then looks at the interoperability of different devices from different vendors. The trainees will take a deeper look into how the ASi slave is coupled to sensors and actuators, and at the same time the trainees will be introduced to how the ASi master works. The course will cover the transmission phases for controlling data exchange, start-up procedures and addressing.

The trainer will discuss how ASi implements portions of the OSI reference model in terms of its communications system. Focus will be on the physical layer of the OSI model (cable, power, etc), the data link layer (messages, error handling, etc) and the application layer (message traces, different types of message requests/responses, etc).

On the practical side, the IDX Training Academy has developed demonstration boards where attendees will get the opportunity to build a small ASi network, giving them hands on experience on installing ASi devices. Trainees will also use handheld tools to change slave addresses and read and write values. They will also be given the opportunity to get the devices into data exchange through some fault finding.

The course will end with a basic assessment on the material covered during the course of the day and it is the hope of the IDX Training Academy that this will give the attendee the basic know-how and confidence to design, build and troubleshoot ASi networks.

For any queries, please contact us through our site www.idxonline.com

I look forward to hearing from you!

Mike

PROFIBUS – Full of adventure

2011-03-05T00:44:00.000-08:00

For some of you, when you hear the word “PROFIBUS” you might cringe because of the problems you may have faced in the past with this fieldbus. When I hear PROFIBUS, I hear adventure, a new challenge and a new solution.

I recently travelled to an African country known for its happy people and great chocolate. That’s right, you guessed it…Ghana! Situated on the north west of Africa along the Gulf of Guinea, it’s a tropical forest teaming with gigantic pot holes (at least the route that I travelled was!).

The next morning,after 20 hours of travel and 4 hours of sleep, I was on my way to try and solve the elusive problem that was plaguing this plant. The problem was described to me as “three devices keep stopping and then we have to manually restart them”. After looking at the voltage levels, signal waveforms, message trace, statistics, etc on my trusty PROCENTEC ProfiTrace my conclusion was that the messages are getting corrupted by noise. Unfortunately there is not too much that can be done in terms of a permanent plant fix when the plant can't be stopped for a reasonable amount of time due to production pressures but the short term solution was to reduce the network speed and increase the retry limit to 3 (which was currently 1) to mitigate the damage. The retry limit is simply the amount of times the master will resend the same message to the same slave before it will flag that device as “not configured” and move on to the next slave. When this limit is exceeded the SCADA will report something like “lost communications to the device” because the device is not in data exchange anymore and often this results in the undesired “plant trip”.

The correct solution will be to rewire the network, keeping the PROFIBUS cable away from the high voltage cables. Where that is not possible they will have to run the cables in an earthed steel conduit. One of the problems they are facing is corrupted messages and since the network is laid out in a line topology, every message that passes that noisy area gets affected. A better solution is to create a star topology using a multi-channel repeater such as the PROCENTEC Profihub. This will reduce the amount of messages getting affected and allow the technicians to isolate which segment is causing problems.

The good news is I left the plant in a “better” running state and post their successful training (yes they all past the installer and engineers course – despite the trainer) with better knowledge on what and what not to do with PROFIBUS..

Where to next? I wouldn’t want to hazard a guess but I know I’m game for anything (even Antarctica)

And I know Jono is off to Abu Dhabi tomorrow to audit an Oil Rig, a first for our PCC!

Softing BC 600 New Features

2011-03-02T22:29:00.000-08:00

What makes this diagnostic device so impressive is that you do not need a PC to diagnose whether your network is healthy or whether maintenance is required. It does have the option to connect using a PC for advanced fault finding

Use the Quick-Test with Stand-Alone-Mode to make a first and simple check on communication and signal quality from both ends of a network.

Communication:

R=3: there were 3 frame repititions during Quick-Test.

E=0: there were no error frames during Quick-Test.

Signal Quality:

Qmin indicates the minimum signal quality in the network and Qmax indicates the maximum signal quality in the network.

Conclusion:

If R=0 and E=0 and all signals are fine in both tests your segment should be healthy. If there are repetitions, error frames or bad signals while measured from one end this tells you that you will have to do further testing.This gives you a good indication of where you should start testing when you connect with the PC.

Need for Tag Synchronisation and Management

2011-02-28T22:41:00.000-08:00

Modern plant systems consist of various real-time data systems, often from different vendors and the data contained in these systems is usually not directly exchangeable. The requirement to share information between these systems has become easier to achieve over recent years due to the advent of standardized data exchange protocols and systems, such as those defined by OPC, or using products such as IDX Data Exchange Server. However, while sharing this real time data has become simpler, the management of the systems producing and consuming this data has not. Currently, if the real time data elements, referred to as tags, are added or removed from the data producers, manual intervention is required to ensure those tags are added and removed from all the consuming systems in order to ensure configuration synchronization between all systems.

Manual synchronization is a tedious process when the systems involved are large, changes are frequent, and where small changes, such as a change in a tag’s maximum value attribute, may go undetected. In the process world, this problem is often seen when plant data is logged into a data historian. In this case, it would be desirable that when changes are made to the source systems, such as the addition of data tags to the plant SCADA, for example, that these tags could automatically be setup and created in the data historian so as to ensure the historian tag configuration remains synchronised with that of the SCADA.

IDX Tag Manager is an advanced, intelligent software solution designed to solve this problem. The principal behind IDX Tag Manager is to simplify this synchronization and management process by:

Providing purpose-built system components that are able to talk directly to the source and target systems involved.
Detecting changes in configurations between source and target systems, and providing detailed information and/or summarised reports of those changes.
Allowing changes to be selectively applied to target systems.
Maintaining a history of any changes made in both the source and target systems.

Key benefits of IDX Tag Manager:

Reduced time & effort to maintain target system such as OSIsoft PI and Wonderware Data Historian.
Systematic, repeatable approach with greatly increased precision.
Provides a level of change control and auditability related to both Source (e.g. WinCC, Citect, Adroit, etc) and Target (e.g. OSIsoft PI, Wonderware Data Historian) Systems.
Responsive local technical support.
Free upgrades if on Software Support .

IDX Tag Manager contains components to communicate with commonly used systems such as Siemens WinCC, Microsoft SQL or custom format CSV files, while targets include Wonderware InSQL Historian, OSIsoft PI Historian, Microsoft SQL and custom format CSV files. Once configured, Tag Manager allows for the continued synchronisation of source and target systems with greatly reduced time and effort but with increased precision, control and auditability.

Please contact us for further information or for a demonstration of the benefits that IDX Tag Manager can provide to your business.

COMbricks

2011-02-28T03:11:00.000-08:00

COMbricks™ - The first PROFIBUS and PROFINET-based automation system that unites network components, permanent monitoring with ProfiTrace and remote I/O.

COMbricks is a modular system that allows a mix of automation components on a backplane. Repeater modules can be inserted next to a PROFIBUS slave and at the same time, in a webbrowser over Ethernet, the condition of the installation can be remotely inspected with ProfiTrace OE.

Applications

Remote maintenance station (ProfiTrace OE)
Modular repeater backbone with hotswap
Transparent datahub; repeaters, fibre optic, RS 485-IS, DP slave, etc.
Gateway between PROFIBUS and PROFINET (DP/PN couplers)
Remote I/O for PROFIBUS and PROFINET

Product features

32 modules (10 high-speed modules)
Wide range of modules available
ProfiTrace OE
Hotswap and extendible
DIN-rail mounting
IP 20

Modular PROFIBUS repeaters

The current trend with PROFIBUS projects is to use segmentation with repeaters, fibre optic and ProfiHubs to bridge the common faults of the end-user concerning his cabling difficulties. COMbricks adds another important element; the creation of modular and random repeater hubs that can be maintained remotely with a permanent internal ProfiTrace.

COMbricks is based on a backplane into which 10 hot swap repeater modules with 2 channels each can be inserted (20 galvanic isolated transparent segments). Every channel can handle 31 devices and maximum 1200 m cable length (depends on the baudrate).

The bus redundancy technology of the repeater modules is very advanced. A redundant system with 10 parallel network cables can be built. This architecture provides extremely high availability. Most suppliers only allow 2 cables.

ProfiTrace OE - Remote monitoring in a web browser

Permanent and simultaneous monitoring of 4 PROFIBUS networks is a powerful feature of COMbricks.Global projects and a shortage of (qualified) technical staff members are causing significant capacity problems. COMbricks offers a solution by remotely monitoring PROFIBUS installations over the Internet and alerting the user by email.

A web server with a ProfiTrace shell visualises the information in an understandable format (ProfiTrace OE). Because of the web browser, additional software is NOT required and a constant connection with a PC to the COMbricks is NOT necessary.

The monitoring and logging is performed by the repeater modules which are inserted in the backplane. COMbricks is the first system that has integrated the busmonitor in the network components. Deploying COMbricks repeaters for regular automation means an automatic availability of ProfiTrace OE.

E-mail messages provide real-time alerts should malfunctions be detected in the PROFIBUS installation. These can be easily set up through the web server.

A brand new functionality within ProfiTrace OE is the device location detection. It gives a detailed overview of on which repeater segment the devices are installed.

This information can be found at http://www.procentec.com/combricks/index.php

My Profibus network doesn't work...

2011-01-14T05:08:00.000-08:00

We are constantly faced with comments about peoples Profibus network problems where, the general consensus is pure frustration.

Helping out with different industries, ranging from precious metals to tissue paper, we have found common issues that if corrected and avoided, all problems fade away.

Some of the issues we have found

Lack of respect for the technology
Managers don't understand the skill requirements needed to successfully troubleshoot and maintain a Profibus network. It is a common occurrence to find unrealistic expectations of staff who have never had any formal training on how the technology works. They are expected to know the ins and outs of Profibus and this is an unfair expectation. The network runs and may be easy to maintain, but if a problem arises, there is no way for the responsible parties to actually perform their required tasks.

Rules are streched until broken
We also hear the statement "But the network has been running and stable for the last 2 years, why is it breaking now?" almost every time someone tries to upgrade their network. We then also hear them say in the next breath that the network trips every 12 hours or once a week. What people don't understand is that a working network does not indicate a healthy network. A healthy network never trips because of the fieldbus, it may trip because of interlocks, but the fieldbus should be completely stable. A network that keeps tripping indicates an unhealthy network and raises issues in the way that the Profibus rules have been implemented. If the rules are followed, then 90% of the possible issues can be removed immediately.

The lack of preventitive maintainence
We also find that once a network is up and running, the network maintenance plan goes out the window, and when things go wrong there is nothing in place to mitigate the effects. This is when things go really bad, because it becomes an emergency to get things up and running again. If there is a simple procedure in place that makes people aware of the things that need to be done in the event of a failed network, then the whole process is controlled, rather than chaos.

So basically I have touched on a few concepts that dont necessarily solve any of your problems right away, but hopefully if you are reading this and you find yourself in the situations I have described, then you are a few steps away from solving your network issues. We provide audits and callouts for those unforeseen issues, and we also provide internationally certified training on the current Profibus technology to get people up to speed so that the mystery of Profibus is unlocked.

Whether you are based in South Africa, or we have to travel outside of the country to Ghana, Namibia, Botswana, or Zambia (to name a few of the countries we have traveled to) we are keen to help solve your problems

If you have any question please feel free to ask!

We Need Your Help!

2010-09-13T04:58:00.000-07:00

Due to the fact that we are mainly left brain thinkers at IDX (what else can you expect from a bunch of electrical and IT engineers) we are having a slight dilemma finding a name for our new solution. Currently it got the name “IDX Brick” but we think it needs a lot more pizzazz. Hence this request for help...

Basic the IDX Brick consist of our Industrial Data Xchange (IDX) software running on an embedded platform happily translating data from an OPC Server to the site’s PROFIBUS network. Pretty neat!

So we would like to extend the invitation to you for you to submit a name that we can label this device with.

Please add your comments to the end of this blog.

IDX successfully hosts its first Anybus breakfast

2010-09-09T03:48:00.000-07:00

IDX recently hosted our first breakfast targeted at the upcoming range of Anybus products available as well as some of current products that are offered by HMS.

Kristina Johansson (Area Sales Manager) and Henrik Arleving (NetBiter Product Manager) from HMS (in Sweden) spent a week with us and enjoyed the good and the bad of South Africa (only bad were taxis). It was with the greatest of pleasure for us to have them and enjoy their stories about Sweden(and there were a lot of them) which they are very proud of!

Probably the most popular topic, of the breakfast, was the remote communication interface devices. The NetBiter module allows you to read analogs/digitals or even Modbus messages into the unit and the information is sent via a GSM/GPRS modem to the server where the information is stored and can be displayed using a very user friendly web interface. (click here for more info).

We would like to thank everyone for their support and we look forward to more of these events in the future.

Brendan Gunn

Anybus Communicator

2010-09-07T03:43:00.000-07:00

So what is it?
The ABC (Anybus Communicator) is a device that translates from serial communication to different fieldbus languages. By default, it is a Modbus master on one end and converts this serial communication to one of the numerous fieldbus options (Profibus, DeviceNet, ControlNet,...etc)

How does it work?
Very simply, the Modbus master requests information from the slave/s that it is connected to and stores that information in its own memory area. That memory area can then be read from the fieldbus in its native language. I.E. Profibus will be able to read the data in the format that it understands. The same applies when the fieldbus writes data to the ABC, the information is stored in a memory area and the Modbus master will then take that information and send it to the Modbus slave.

Is it easy to setup?
The ABC software is very user friendly. You need to have a basic idea of the Modbus protocol and setup the commands and addresses of where you would like to read and write the information. The fieldbus translation is all done automatically. All you need to concern yourself with is the Modbus setup and if you need any help you are more than willing to ask us.

Versions?
There are 2 versions that you can get. The first is the standard type, this is used for normal Modbus communication and simple serial communication. The second type is a java unit for more advanced applications where programming the unit for uncommon/ user specific protocols/ languages are needed.

Applications?
Recently a customer asked if the ABC would be able to communicate with his scale. The scale had its own custom ascii (text is represented by numbers using an ascii table, ie “M” = 77 decimal) language. The device didn’t require complex communication but they wanted to get this device to communicate on a Profibus network. I used a standard ABC and built the message structure (which you can do with the configuration software) according the specification given to me. In this case they were using RS232 that they usually connected to their computer and set the values using hyperterminal, now this company can sell their unit to people who want to control the unit over Profibus and almost any other commercial fieldbus.

The ABC is a device that converts from Modbus (serial communication RS232/ RS422/ RS485) to any of the following fieldbusses: CANopen, CC-Link, ControlNet, DeviceNet, FIPIO, Interbus, Modbus Plus, Modbus-RTU, Profibus.

Send us an email or call us if you are interested.

Brendan Gunn
info@idxonline.com
011 548 9960

IDX introduces OPC to Profibus (Profibus to OPC ) device

2010-09-06T06:59:00.000-07:00

So I have been bugged by my colleagues to get this post out into the world. Now as an engineer the last thing on my to-do list (as most engineers) is documentation and I'll be honest, blogging wasn’t even on my list, so this is a big step for me...

I trust and hope that it will answer some of your questions, and even present a possible solution to some of the problems you may have. (Although I also realise the success of this blog is coupled to the frequency of future blogs I may be forced to write...)

Anyway at IDX we excel at solving problems, and we were faced with a problem which begged our attention. Long story short we created a product that exposes your required OPC tags onto your Profibus Network as a Profibus Slave, or vice versa if you like (Profibus to OPC). (Now I would like to end my blogging career right here, but I know if I don’t give more details I will just have to edit this later... so I will continue. )

The Background
We were approached by Sandvik South Africa to solve one of their clients’ connection issues. Sandvik was supplying a ASRi crusher controller to them and they wanted the data from the ASRi available on their Fieldbus network. The data was already exposed as an OPC server, but that was not the solution the client wanted. They argued that they had already spent money on creating a Profibus infrastructure, and they therefore wanted to use what they already had. So the age old mantra of “The customer is always right” prevailed and Sandvik had no choice but to provide what the client wanted. Sandvik then followed the yellow brick road, and found their way to IDX, and the developing fun began...

The Solution
One of our strategies at IDX is to make long term, maintainable solutions that are not locked into any one specific vendor. We also leveraged the power of our software which has been running in industries all over the world since 1995, so what we ended up with is a highly configurable, highly maintainable solution which guarantees a long life time to its users. With an initial setup to configure the relationship between the OPC tags and the Profibus memory mapping, we now have a fairly simple way of exposing any OPC data onto a Profibus network.

We were also able to expose the Profibus acyclic data as well as the cyclic data on the device so you are able to put pretty much all the data you would ever need onto the profibus network.

But wait...

The Exciting Part
Because we used off-the-shelf products and used the HMS Anybus PCI card to provide the Profibus interface, with a few minor changes we can include any of the HMS interface cards and use the same idea of OPC to Anybus... This means if you want OPC on DeviceNet, Modbus, ControlNet, CanBus, pretty much anything you have, we can now bridge the gap. (I suppose this is why they wanted me to write this message... )

And then it was done...
I am really excited about this new product we are offering and I really had fun playing with all the technologies. If you have any questions or any comments or ideas you would like to chat about please feel free to contact me. I spent a lot of time digging through the different protocols so if there is something you need or would like to know, give me an email. I would love to know what you are doing and would love to help! (...I like problem solving a whole lot more than blogging!)

OPC End User Training course in South Africa

2010-09-03T06:28:00.000-07:00

IDX now has a 1 day End user training course for the end user who wants to become competent in OPC.

The course starts by covering the basics of OPC, then moves on to the details of the different types of OPC, how they differ, how to use them and where they fit in on the plant.

There is also a practical section where the users are taught about security and how to set up the dreaded DCOM.
After this course, DCOM will become child's play.

The user is left empowered with the knowledge of OPC in it's entirety.

Contact idxonline for more information on these and other courses.

New Embedded Solutions

2010-06-29T00:20:00.000-07:00

IDX provides unique embedded communications and remote monitoring solutions that solve unique industrial communications problems where a complete, drop in solution is required. These embedded solutions make use of the ever increasing processing power available in a small, industrially rated hardware footprint and Windows Embedded operating systems. For remote monitoring or alarm/event notification, IDX makes use of hardware purpose built for vehicular remote monitoring with integrated SIM card and unique features such as vehicle ignition state detection and delayed shutdown capabilities. An example application of IDX remote monitoring solutions is the IDX RM (remote monitoring) system developed for Pilot Crushtec, for monitoring mobile rock crushers. The RM units are mounted on the crushers, and collect crusher control system data, from the onboard PLC (MODBUS RTU) and also the crusher’s engine (J1939 CANbus). All data is logged on the RM unit and ultimately transmitted, via GPRS or 3G to a web/database server. A web portal allows Pilot Crushtec and other users to monitor customer crushers, schedule services and diagnose problems and issues remotely.

Profibus...HELP!

2010-06-10T02:48:00.001-07:00

For most of us there was a stage in our lives, while growing up, that we went through, that involved us being the doctor and one of our friends being a deathly sick patient. Although we as juvenile doctors had very little experience and what I mean by very little is nothing at all! Usually we would prod and poke our "patients", and after sometime, they would bounce back to life and we would all proceed to go and play in the sun.

Much of what I have seen with PROFIBUS problems can be compared to our “doctor! doctor!” days. Lets run through a short case study...a problem occurs onsite..."THE NETWORK HAS DIED", what follows is an assault of prodding and poking until miraculously the network is up and running leaving all involved feeling exhilarated over a job well done but not really knowing what was done to fixed it.

Here are some practical tips on how to help solve your problem and hopefully leaves you feeling a little bit less like you are alone in the dark:

The blind leading the blind

If you know nothing about PROFIBUS, be honest and call an expert. I have never heard of anyone taking their Lamborghini Murcielago to a chop shop on the side of the road to get the exhaust spot welded.

Your weapon of choice

Just like every good doctor has his/her stethoscope and surgical blade so too do you need yours. Unfortunately most of the time people want to operate on their PROFIBUS network with a spoon and end up bludgering it to death. It is important to know the different options that you have when it comes to PROFIBUS diagnostic tools. There are two different types of test tools, a physical line tester and a message/protocol analyser. Both are invaluable and are required to diagnose the full spectrum of problems that you may face. Some of the functionality that you would want to look for in a message/protocol analyser is: Bar graph, oscilloscope, message recording, reporting, trigger ability to start message recording when a fault occurs and preferably some master functionality.

Be doctor doc

Know what the PROFIBUS installation requirements are. I can’t stress this enough, most faults are caused by bad installations and lack of knowledge. Some of the most common errors are incorrect terminations, PROFIBUS cables cable tied to high voltage lines running for hundreds of meters. By understanding what the "dos and don’ts" of PROFIBUS is will help you to identify where the problems lie.

Identifying the problem

In most cases this should be evident by looking at these 5 tips and tricks.

Tip 1# Walk the line
It’s important to know what is physically happening along the PROFIBUS cable. Things to look out for, terminations, stub lines, devices that don’t use D-Sub connectors because they may have a built in termination switched on, location of high voltage lines, lengths of PROFIBUS cable, amount of devices in the segment and the type of cable used. Your problem may be found by simply looking at the network.

Tip 2# Best bar around
Look at the bar graph to determine if any of the voltages are below the 2.5v threshold. If there is one device that has a low voltage level then focus your attention on that device. If multiple devices have low voltage levels then have a look at that specific segment. Unplug one device at a time to determine if that device may be causing the problem.

If the voltages all the voltages are fluctuating then there is a large chance that you have a dirty/floating earth or if one devices voltage is fluctuating a lot then you might have a duplicate address on that device.

Tip 3# Catching the perfect wave
Have a look at the signal waveforms, the waveform should be a square shape. A small spike may be present due to the fact that you have plugged in the diagnostic tool. If the signal is not square and contains reflections (wave like signals that die out then are repeated again) or spikes, look for incorrect termination, over termination or stub lines. These types of errors can easily be seen on an oscilloscope. The advantage of using a PROFIBUS test tool oscilloscope is that you can look at the signal waveform for each slave as opposed to seeing all the waveforms and not knowing which device that specific signal originated from.

Having a physical line PROFIBUS tester is helpful in these situations because you can test if the terminations are in the correct locations and not over or under terminated.

Tip 4# Track and trace
Use your message trace to record messages. This will give you an excellent idea of what the error may be. The two most common types of errors are broken messages and configuration errors. Broken messages are predominately caused by noise in the cable, breaking the messages or by slaves speaking at the same time causing message collisions. Configuration errors will not allow the device to enter data exchange or if the device was in data exchange and something broke in the device, then the device will fall out of data exchange.

Tip 5# Isolation
In some situations it may be difficult to find what the cause of the problem may be. Most modern PROFIBUS D-sub connectors break the outgoing line when the termination is switched on. This is extremely helpful and allows you to add one device to the network at a time. By doing this you should be able to find which device is causing the problems on the network.

Tip 6# I need backup
If all else fails...give us a call we are more than willing to help you in your desperate time of need.

If you are looking for some PROFIBUS test tools, we sell and use them on a daily basis for audits and training.

Brendan Gunn
brendang@idxonline.com

Siemens PCS7 Direct PLC Tag Data Retreival

2009-09-22T22:46:00.000-07:00

Exciting Work in Development at IDX
TOPIC: PCS7 Direct PLC Communication via IDX Runtime

Background:
IDXOnline has an exciting solution in development to solve a long–standing challenge which involves collecting plant data directly from the Siemens PLC as opposed to from the WinCC OPC Server.

Out with the old:

In With the New:

How will we achieve this?
IDX has obtained a dll package from one of our partners that are able to communicate with a Siemens PLC via TCP/IP. The package is suitable to be incorporated into the IDX runtime as a driver module, and thus will work like any other IDX driver module will enable communication with any other software that IDX currently supports.

Is there already software available that can do this?
Yes. IDX has tested the Softing S5/S7 OPC Server as well as the Wonderware DasSIDirect Server, and the results that this test yielded were impressive when compared to the standard WinCC OPC server. A report of the findings is available and can be provided on request.

The shortfall with all existing products of its kind is the fact that when a full download is done from the PCS7 Engineering Station to the PLC, the DB Addresses change. The result of this is that tags now no longer point to the same piece of information in the PLC.

So, for example, before a download, the tag 440LIC104 at address (DB44,DW3) would point to a level indicator and after the download, if the address mappings are not updated, DB44,DW3 might now be the address of a furnace temperature, etc.

The new IDX Driver will detect this download and set the quality of the tags to BAD until the new addresses have been updated using IDX Unifig, after which the driver will continue transmitting the tag data.

For more information contact

Ryan Coetzee - IDX
ryanc@idxonline.com

www.idxonline.com

C# COM issue : "the application has called an interface that was marshalled for a different thread”

2009-09-07T05:27:00.000-07:00

Hello people. I bled a little on something, so I thought I might share and save you some pain:

When calling code in a com class (for example, when using an external dll written in some other language (vb, for example), the implicit threading can be an issue)

VB by default uses STA threading (Single thread apartment), which loosely means that the application runs in one thread.
If you use the above class in C#, which by default uses MTA (Multi thread Apartment), You get an error : “the application has called an interface that was marshalled for a different thread” .

SO:

When you use such a dll in c#, you need to add the [STAThread] directive above your main program.cs file as follows:

namespace MYIDXApp
{
  class TimeServer
  {
    [STAThread]
    static void Main(string[] args)
    {
    }
  }
}

Furthermore:
There is a “feature” in c# that even though you specify that the main thread runs under STAThread, any timer events happen as MTAThread.

Thus, for a timer event, you must launch a new thread under STAThread as follows:

void timer_Elapsed(object sender, System.Timers.ElapsedEventArgs e)
{
  timer.Stop();

  //Classes.IDX_PI_Processing oProcessing = new Classes.IDX_PI_Processing(config);   // these have now been moved to a new thread due to the issue
  //oProcessing.ProcessPIQueue();
  Thread t = new Thread(new ThreadStart(StartNewStaThread));
  t.SetApartmentState(ApartmentState.STA); // this has to be done BEFORE the thread   //starts, else it is too late
  t.Start();
  t.Join();

  timer.Start();
}

private void RunProcessingClass()
{
  Classes.IDX_PI_Processing oProcessing = new Classes.IDX_PI_Processing(config);
  oProcessing.ProcessPIQueue();
}

for further reading:
http://www.developer.com/net/cplus/print.php/2202491

Scheduling the printing of an Excel file which has an add-in from the command line using visual basic scripting (vbs) via wscript

2009-08-25T07:43:00.001-07:00

On a recent project I was required to print out an Excel based report which made extensive use of OSIsoft PI DataLink's Excel Add-in on a sechduled basis (7am daily).

Unfortunately Excel does not easily allow for the printing of an Excel file via the command line via switches or parameters when calling Excel.exe (e.g. C:\Windows\MS Office\Excel.exe -print "C:\Reports\My Report.xls").

I was able to find examples on the Internet which made use of cscript or wscript where one calls VBS code, and where one provides the file name as argument, for example:

wscript "C:\Data\My Scripts\printXLS.vbs" "C:\Data\My Reports\Daily Analyser Excursion Report.xls"

Note the convention of using "" around full path filenames as they contain spaces.

The file printXLS.vbs would contain something akin to the following code:

Dim XLApp
Dim XLWkbk
Dim ObjArgs

set ObjArgs = wscript.arguments
if ObjArgs.count <> 1 then
wscript.echo "Invalid passed arguments"
wscript.quit
end if

Set XLApp = CreateObject("Excel.Application")
XLApp.Visible = False

Set XLWkbk = XLApp.Workbooks.Open(objargs(0))
XLWkbk.PrintOut
XLWkbk.Close False

XLApp.Quit

Set XLWkbk = Nothing
Set XLApp = Nothing
Set ObjArgs = nothing

The problem I experienced was Excel Add-ins are not automatically loaded in Excel applications created via Automation. This resulted in the Excel file printing but with OSIsoft PI DataLink Excel Add-in functions not being recognised and #NAME! appearing in the relevant cells on my printout.

The solution I found was to explicitly load the Excel Add-in via XLApp.RegisterXLL ("fullpath filename")

So my VBS file looked like something this:

Dim XLApp
Dim XLWkbk

Set XLApp= CreateObject("excel.application")

XLApp.Visible = FalseSet XLWkbk = XLApp.Workbooks.Open("C:\OSIsoft\Reports\Scheduled\PI Report - Analyzers - Quality Excursions.xls")
XLApp.RegisterXLL ("C:\Program Files\PIPC\Excel\pipc32.xll")

XLWkbk.Worksheets("Report").Calculate
XLWkbk.PrintOut
XLWkbk.Close False

XLApp.Quit

Set XLWkbk = Nothing
Set XLApp = Nothing

I also wanted to be able to specify the number of copies to print and which printer should be used namely PRC2 in my case. If the printer is not specified then the windows default printer is used.

I also decided to allow one to specify the Excel workbook and which specific worksheet in the Excel workbook to be printed.

So allowing for parameters the VBS look something like this:

'Arguments'1 Excel Name e.g. "C:\OSIsoft\Reports\Scheduled\PI Report - Analyzers - Quality Excursions.xls"'
2 Worksheet Name e.g. "Report"'
3 Printer Name e.g. "PRC2"'
4 No of copies e.g. 1

Dim XLApp
Dim XLWkbk
Dim ObjArgs
Dim strFileName
Dim strWorkSheetName
Dim strPrinter
Dim intCopies

Set ObjArgs = wscript.arguments
If objArgs.count <> 4 Then
wscript.echo "Invalid Passed Arguments"
wscript.quit
End If

strFileName = objargs(0)
strWorkSheetName = objargs(1)
strPrinter = objargs(2)
intCopies = objargs(3)

Set XLApp= CreateObject("Excel.Application")
XLApp.Visible = False
Set XLWkbk = XLApp.Workbooks.Open(strFileName)
XLApp.RegisterXLL ("C:\Program Files\PIPC\Excel\pipc32.xll")
XLWkbk.Worksheets(strWorkSheetName).Calculate
XLWkbk.PrintOut , , intCopies, , strPrinter
XLWkbk.Close False
XLApp.Quit

Set XLWkbk = Nothing
Set XLApp = Nothing
Set ObjArgs = Nothing

I was then able to use Windows Task Scheduler to call the VBS file to print my Excel files on a daily basis.

Handling Late Data

2009-08-10T23:25:00.000-07:00

Handling "Late Data" into a historian can be tricky when that data changes over time.

For example, we have a situation where material arrives in a truck on a weighbridge for processing. A sample is taken and sent to a laboratory for composition analysis but in order that the process can continue without waiting for the lab results, estimates are made and stored in the historian for temporary use.

After some time, once analysis has taken place, the actual values then replace the initial values (and the temporary historian entries for that timestamp must be updated) so that more accurate calculations on the given data can be performed.

This back-tracking and synchronisation of historical data and more have been incorporated into our IDX Listener technology to allow for efficient handling of these 'late data' into a historian.

Download PPT Show

Profibus PA for Hazardous Areas

2009-08-03T06:28:00.000-07:00

Presentation and Paper by Michael Bean on the use of Profibus PA for Hazardous applications.

Profibus PA was designed as a solution for automation in Process Applications where it is often necessary to guarantee levels of safety with regard to potentially explosive atmospheres. In this paper and presentation given at the Hazardous Areas Conference held at Gallagher Estate in 2008 I discuss Profibus PA's applicability to such applications.

The presentation raised quite a bit of interest as various parties debated their companies' acceptance of the FISCO. Many were surprised at the advantages offered by the "high-powered trunk" concept.

Download Paper
Download Presentation Slides