6/7/2014 7:55 PM | |
Joined: 7/2/2008 Last visit: 4/5/2024 Posts: 928 Rating: (305) |
Hello Profibus fans, 1st let me admit that I'm a Profibus fan toobut we all must accept the fact that the future is for Profinet. So, Profibus fanatics should start to change their minds/preferences/opinions and be ready forthe wind of change(that already took place).
Navang, I see it a bit contradicting to some documents you have shared in yourvery nice tip. In some of these documents, you can read "Profinet is a further development to Profibus DP.However, it has many more advantages". Apart of redundant IOs in 400H systems and Profibus PA, I see that Profinet is equivalent (if not better) for field equipment (Sensors, Remote IOs, Safety IOs and drives) and maybe cheaper when it comes to fiber optic ring networks. I mean better in terms of speed, diagnostics and flexibility (ring-star-line). Many years ago, the 4-20mA fans were refusing to switch to new fieldbus technology (FFor PA) and they thought that 4-20mA will last forever. Now, these guys (who missed the fieldbus) find themselves lost when they hear aboutwireless HARTand Ethernet transmitters. Their time has stopped at the 4-20mA and they can't realize that the world has become more complicated but more faster. I hope Profibus fans will learn from the fieldbus lesson and understand that late is better than never. IMHO, The only real obstacle for Profinet is still the process automation. However, I've been told (in 2010) by one of the Profibus PA/PDM Siemens engineers that sooner or later Profinet will have to come down to instrument level and there are much development to use POE (Power Over Ethernet) to solve this issue. Nevertheless, there are still problems making Profinet (Ethernet) intrinsically safe. Meanwhile, you can find now in the marketsome Ethernet transmitters and when you look at the idea you get the feeling life will be much more faster and much more easier. (Just can't wait to see the PDM is not a turtleanymore.) Best regards, H-H |
Last edited by: H-H at: 6/8/2014 1:27 PMLast edited by: H-H at: 6/7/2014 7:56 PMA link was missing |
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6/9/2014 10:03 AM | |
Joined: 11/21/2007 Last visit: 3/14/2024 Posts: 2323 Rating: (306) |
Thanks H-H for such a detailed analysis First of all, let me say that I fully agree with you that the winds of change are certainly flowing towards Profinet ( for better or worst ) The Documents that I postedwerebased on the point of views of their writers and though I agree with a lot of what is propagated in these documents, I cannot say that weshould blindly follow them. Ultimately there is always some amount of marketing that trickles intomost such documents so we need to take everything with a pinch of salt. No doubt, we shall see Profinet overtaking Profibus sooner or later, however for that to happen, many big and small niggling issues will have to be sorted out for it to be a true successor to profibus. Few of the practical problems that we face ( Some of these are quite basic actually ) need to be overcome for profinet to be successful on the field side. : a) Many Profinet devices still do not come withbuilt-in 2-port switches, forcing us to install Ethernet switches andtheir power supplies adding to the costs and the hassle of installing the switches in field or inside third part cabinets / equipments. b) Even if the 2-port switches are present, unless we go in for a Ring structure ( Not always feasible ), thedownstream network gets interrupted if one node isswitched off or taken out for maintainence.(In Profibus, we can simply switch off any slave or removethe profibus connectorwithout any major issues, except additional cycle time ) c)In most large companies, the IT department comes into picture as soon as any Ethernet network is to be installed and it is extremely difficult to explain to them why we need Ten times more expensiveLAN cables, Connectors and switches. ( Since they are used to installing ordinary CAT5 cables and There is always a tendency to useLAN cables, connectors and switches etcfrom IT infrastructure. With this, although the network will work initially but will start giving trouble a few months down the line, giving us a bad name ) d) You just need a laptop + LAN cable to be able to get into a profinet system and be able to access it and configure it . You don't have to connect physically to the network( Due to easy remote connectivity ) for any Genuine / Mischivious modifications. This is a Boon as well as a Bane, depending upon the way you look at it. Undoubtedly thechallanges of industrialnetwork security increase maniold once you switch to Profinet ( an more so, if you connect your systems to the company networks, even if you are using firewalls ). Despite having achieved many functionalities, there are still many functionalities of Profibus, where Profinet falls short. In short, the transition from profibus has to be carefully thought of and planned Cheers Navnag |
Last edited by: Navnag at: 6/9/2014 1:41 PMSpell Check There is no such thing as the last bug in a program |
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