HMS Industrial Networks

Transcription

1 HMS Industrial Networks The guide to connecting automation devices to industrial networks Whitepaper Five ways to connect devices to fieldbus and industrial networks. HMS Industrial Networks AB Stationsgatan Halmstad Sweden Tel: Internet:

2 Introduction OK, so let s say you have constructed the best industrial automation machine ever made. The automation market is going wild about your new invention and you get requests from factories in Sweden, Germany, Japan, the U.S. China and Brazil (to name but a few). The problem is that all the factories use different industrial controllers and networks and your machine needs to connect to all of them. How do you get multi-network connectivity in a way that suits your particular device? Here is your guide to the five main ways of getting a device connected to industrial networks. Happy reading!

3 Part 1: Five ways to get connected and their pros and cons 1. Use an external protocol converter (gateway) A gateway works as an external translator between your device and the controlling network. This is your choice if you do not want to make any changes to the software and hardware of your device. You just connect your machine to the gateway to enable communication with any industrial network. (Image examples below from HMS Industrial Networks) It doesn t matter if your device communicates via CAN, RS232/422/485, Modbus RTU, DF1 or any other serial protocol The gateway translates the communication between your device and the industrial network. Gateways are by far the fastest and easiest way to get an automation product connected to a network. The most user-friendly gateways offer PC-based configuration software to set up the connection between the machine and network. This means that no programming is necessary. The configurations can be saved and re-used further diminishing the installation work. There are also gateways which translate between two different networks which can be very useful when integrating different systems in a factory for example. Gateways are external by design which can limit their use for certain products which require that the communication solution is embedded inside the machine. They are generally not used for automation devices produced in high volumes since gateways are more expensive than embedded solutions. In short: The fastest and easiest way to get connected. The best choice if you only need to connect a limited number of products (and you don t need an integrated soluton). 2. Plug in a complete communication module An embedded connectivity module is by far the most popular choice for multi-network connectivity the industrial market today. Why? Because it is easy. Companies want to focus on building machines and don t want a whole department working with networks and connectivity.

4 With a pluggable communication module, you do a one-off development project where you design in a mechanical and electrical host slot with a connector, and prepare your machine for communicating with the module. After that, you can simply plug in the module that corresponds to your desired network. The leading manufacturers of communication modules offer connectivity to more than 20 networks, simply by plugging in a new module. It is even possible to plug in the module of choice at your own premises, simplifying the logistic chain. The best communication modules are pre-certified for different networks reducing your certification work with the network organizations substantially. So what are the downsides? For most industrial automation products, a standard communication module has all the functionality needed to make them multi-network-enabled, but it is a finished solution meaning that you may not get exactly the hardware design you want. A module is usually more expensive than a chip or brick solution (see below), but is also a more complete solution requiring less development work. In short: An complete solution for embedding multi-network connectivity into your device. 3. Embed a ready-made communication brick A communication brick is basically the same as a communication module (all software and hardware is included), but you add your own connectors. This gives you more freedom design-wise. A brick solution is often preferred if there are mechanical constraints or IP classes to consider, since it can be embedded in a very flexible way. Just like the module, a brick comes with all software you need to handle communication between your product and the network. After you have designed in the brick into your product and established communication between your device and the brick, you can connect to any network by simply switching brick. For industrial networks, there are even modern brick solutions which offer the possibility to use the same brick for several different networks. This means that you simply download new software to enable your machine to communicate with a particular network. Want connectivity to another network? Just download another software package. Since the brick also includes hardware, you do not have to worry about BGA design and advanced production, as you would if you were to design the hardware yourself. Some communication bricks are pre-certified for different networks reducing your certification work substantially. A brick is usually slightly cheaper than a complete module and are commonly used in products running in high volumes. In short: Software and hardware included, just add your connectors and peripheral components.

5 4. Customize your solution around a communication chip A communication chip consists of a network offloading your from communication tasks, plus the software you need to connect to different networks. With a chip-based solution, you can design the hardware exactly as you wish around the chip. There are several types of communication chips. Some are more or less empty shells where you add your own software stacks and do everything from scratch. In this case, you end up with a solution which is more like an in-house solution (option 5 below). On the other side of the spectrum, there are chips loaded with complete software solutions for multi-network connectivity where you don t have to worry about network upgrades and maintenance once the chip is in place. This latter type will save you a lot of time later down the line since you will get software updates whenever networks are upgraded or when there is new functionality available. This can be time-consuming if you need to handle it yourself. For industrial networks, you can use the same chip and just download different software to be connected to the network of choice. A chip is a good solution if you manufacture a lot of products and want to minimize costs since you can choose components and design around the chip. It does, however, require more work in the design phase, and you need to have some knowledge of network communication when it comes to connectors and hardware. You also have to cater for more in-house testing than you have to with a more ready-made solution. In short: A chip solution gives you a lot of flexibility, but requires more of you in the design phase. 5. Build your own connectivity solution from scratch This is your choice if you want to have full control of your connectivity solution. You will make your own in-house design for hardware and assemble the necessary parts. You will also create your own software using stacks etc. to enable the communication between your device and the network. You will need to build the expertise about your chosen networks inhouse which will give you a lot of knowledge about industrial networks and connectivity. The downside is that this takes a lot of time and resources which you have to take from your core competence (developing the best industrial automation device ever). You have to keep up with network updates, and whenever you get demands for connecting to a new network, you have to start from scratch to create connectivity for the new network. If you only need to connect to one network, this just may be a viable solution, but as soon as multi-network connectivity is needed, most companies find that this way is resourcedemanding and more importantly, takes resources from their core business. In short: In-house design gives you full control but it is resource-demanding.

6 Part 2: Aspects to consider when choosing communication solution Make or buy? The major choice you have to make as a device manufacturer is whether to develop a network connectivity solution in-house (choice 5 above) or use a solution provider (choice 1-4). An in-house connectivity solution may give you exactly the solution you want (at least in theory), but you will spend a lot of time and resources in designing, verifying and certifying your solution and you still have to cater for the maintenance of each part yourself. If you want to connect to a new network, you have to start over from scratch and create new hardware and software for the new network. This increases the complexity, especially if you have many networks to connect to. Developing and assembling your own solution One solution for all networks Network 6 Network 5 Network 4 Network 3 stacks industrial stacks industrial stacks industrial stacks network fieldbus/ Complexity Network 2 stacks fieldbus/ network Implementation and support from solution provider Network 1 stacks fieldbus/ network One solution for all networks Generic stacks fieldbus/ network Develop multi-connectivity in-house Buy a ready-made solution

7 With a ready-made solution (Gateways, modules, bricks and some communication chips), you have a unified solution covering all s needed for network connectivity. You don t have to worry about updates to stacks and network certifications since all is included in your solution. Most importantly, it is easy to get connectivity to another network by switching product (For networks, you can even use the same hardware and just download new software for the respective networks.) If you only require connectivity to one network, it might be a viable solution to develop the network connectivity yourself, but as soon as two or more networks are needed, most device manufacturers notice that complexity (and thereby costs and resource-demand) increases substantially as each network requires a start from scratch with new software and hardware and a new development project. Many device manufacturers have realized that when multi-network connectivity is needed, a ready-made communication solution can lower development costs by as much as 70 %. Costs vs time Before selecting a communication solution, it is good to consider how much time you want to put into developing network connectivity and how much money you are willing to spend on a finished solution. If you do more development in-house, you can cut down on purchasing costs, but it will lock up considerable resources for your development department, which is also a cost. When looking at the costs vs. time aspect of our 5 different solutions, there is no alternative that is both fast and cheap (is there ever?), so what you need to consider is the relation between costs for buying communication products and the time you want to spend on developing functionality for connectivity. COST Gateways Modules Brick TIME Develop your own Chip Costs (purchasing and development) vs. time when developing multi-network connectivity. For gateways, costs vary with volumes. If volumes are low, this is the cheapest solution since there is no indesign work. If volumes are higher, this is a more expensive solution. For chip solutions, development time will vary depending on how much software is included on the chip.

8 Control Another aspect to consider is how much control you want over the solution. If you design your own solution, you maximize your control and do not have to rely on suppliers at all, but this also raises costs and the resources demanded from your development team. Gateways Module Brick Chip Develop your own CONTROL The amount of control you have over different network connectivity solution. Data transfer speed between your machine and the network (latency) Some industrial devices only rarely get data changes from the network. This could be for example a motor which only needs to be started and stopped a few times per day. These applications are therefore not that dependent on fast data transfer between the machine and the network. Other devices however, such as synchronized drives and motion machinery, require almost instantaneous data transfer with as little delay as possible. There are today off-the-shelf communication solutions offering very low latency between the network and the host device. Some high-end solutions offer data transfer of up to 1500 bytes in each direction and a latency down to 15 μs (microseconds). Support for network-specific features Networks vary greatly in complexity and performance, from sturdy I/O bus systems like PROFIBUS to advanced Industrial networks like PROFINET, Powerlink and EtherNet/IP. Network features like drive profiles, energy profiles, safety, motion and clocksynchronization are constantly being developed and updated by the network organizations. If you want your machine to comply with these features, you need to have a communication solution that supports them. It is always a good idea to scrutinize the different communication solutions to see what network features they support. Security Security is becoming increasingly important as plants and factories become more and more connected to the Internet. This inevitably opens the door for cyber attacks such as for example when hackers gained full access to NASA s Jet Propulsion Laboratory that commands 23 spacecraft in To protect yourself against cyber attacks, you will need a communication solution with gatekeeper functionality such as software signatures preventing unauthorized software to be downloaded to the machine.

9 So which solution fits you? As you can see, there are several types of solutions to choose from and many aspects to consider when selecting a communication solution. The choice of communication solution depends on your requirements for flexibility, communication speed and, of course, how much time, resources and effort you want to invest. Also, your requirements may change as the market progresses or new arises, so you will always be favored by choosing a solution that is flexible and easily updated. No matter which solution you choose, you can rest assured that your investment will be worthwhile. Network connectivity will continue to become increasingly important as the automation world becomes more and more interconnected.