Difference between PROFIBUS and Industrial Ethernet Feb 22, 2002 11:54 am, by Jose Sousa Subject : Communications Text : I will take a decision to choose a method of communication between S7-300 PLCs. I do not if i use PROFIBUS or Industrial Ethernet. Can anyone give some help. Best Regards Jos?Sousa Reply -------------------------------------------------------------------------------- Re: Difference between PROFIBUS and Industrial Ethernet Feb 23, 2002 11:03 am, by CJ PROFIBUS is A Token Network base on RS485,and for that is more safe. Industrial Ethernet is, as the name tell, Ethernet,faster but less safe. Best Regards CJ for more information go to http://www4.ad.siemens.de/ Reply Re: Difference between PROFIBUS and Industrial Ethernet Feb 24, 2002 12:43 pm, by David Lawton If your network will purely be Siemens kit I"d stick with Profibus. If you have other manufacturers kit involved I"d be tempted to go ethernet. The other thing to consider is the comms speed vs. how robust it needs to be, as mentioned already Reply Re: Difference between PROFIBUS and Industrial Ethernet Feb 24, 2002 12:52 pm, by R.A. Hulsebos Can you explain why the presence of a token makes a network more <quote>safe<unquote> ? Ethernet isnt always faster than Profibus either, because it has a much larger overhead, and the 10 Mbit/s is just used to compensate that. Do some calculations before you make a decision! Rob Hulsebos rahulsebos@cs.com Reply Re: Difference between PROFIBUS and Industrial Ethernet Feb 25, 2002 10:44 am, by david mertens Both networks can be used for this type of communication with the same reliability (When S7 connections are used in both cases) and the same programming effort. The costs will also be similar (CP341-1 versus CP341-5), both systems offer the possibility to construct redundant rings, etc... However, the future trend is more towards ethernet. One advantage of industrial ethernet is speed, up to 100Mbit/s versus 12Mbit/s for profibus. Future releases of siemens CPU"s will have on-board ethernet connections, making this the default standard for communication. Reply Re: Difference between PROFIBUS and Industrial Ethernet Feb 26, 2002 3:49 pm, by Gabriele Corrieri I not agree these opinions ... I"d remember that only ProfiBus (and all of other fieldbus, but not Ethernet) is deterministic ... the cyclic query on slaves on ProfiBus is time-determinated by token-passing, on Ethernet there is a CSMA/CD, otherwise called "casual access to bus" (is not the explanation of CSMA/CD but is very near to the reality), every bus-partecipant access to bus only when it had to exchange datas, and for example can access to bus for more times consecutives, or on the contrary not access for more times, then there isn"t a unit-fault-check on bus, and the datas could arrive after *a not determinated* time before are avaiable on slave. Ethernet, vice versa is more fast than ProfiBus or other FieldBus (I"m not sure that is more fast that LINK2 of Eurotherm Drives), and is more simple to admin than Profibus and is designed specially for high levels of ISO/OSI "tower": is design to communicate from PLC to SCADAs, to office, administration, delivering ... (don"t lost that first release of Profibus was called FMS FieldBus Message Specification, and now we talk on release called DP (decentralized periphery) made for low-level osi tower.) I"d excuse for my very complicate explanation, and errors that I wrote ... but I invite everyone that is interested to write me directly. Gabriele Corrieri gabriele.corrieri@tin.it Reply Re: Difference between PROFIBUS and Industrial Ethernet Feb 25, 2002 2:32 pm, by Friedrich Brabandt For communication between Modicon and Siemens S7-300, i have used the Siemens Communcation-Module CP341 with loadable Modbus-Master Driver. Siemens is Master, Modicon is Slave. I used this type of