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What are my wireless options?

Created by: N01UNO at: 8/26/2009 11:36 PM (6 Replies)

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8/26/2009 11:36 PM	Rate (0)
N01UNO Posts: 3 Rating: (0)	I am looking for some information and a little direction in a communication option for a client of ours. Currently this client has a 315 PN/DP communicating to three wago remote drops and three VFDs all on profibus and there are three computers with touch screens communicating on profinet. My problem is that this system is on a drilling rig and the comm cables being used are fiber-optics. They are continuely having to replace these cables and proving to be a very costly process. I would like to present a wieless option to them your comments and guidance would be greatly appreciated. Ihave attached a pdf of the system for further clarification. The distances between the buildings are aprox. 75m and are in line of sight. Attachment Communication Layout.pdf (179 Downloads)
N01UNO Posts: 3 Rating: (0)
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8/27/2009 11:19 AM	Rate (0)
INS Gold Member Joined: 4/6/2006 Last visit: 2/5/2024 Posts: 604 Rating: (56)	Hi, It's kind a hard to design a WLAN system with this information only. You are talking about drilling and fixed buildings does this mean that the buildings need communication but the drill equipment it self doesn't? Let's assume everything is fixed and not moving. Keeping in mind that you need at least a 60% signal strength and you have to communciate over a radius from150 meter. This will be hard with only 1 antenna. The best way to go would be using a Dual AP (Scalance W788-2RR or W786-2RR) with both interfaces running on 5 GHz (due to most interferences are to be expected in 2,4 GHz). And as a client device you should use the IWLAN/PB Link PN IO which supports up to 8 Profibus devices. Antennas to be used could be the ANT795-6DN on both sides. Something which is a way to go but which should be tested is using a Single AP (Scalance W788-1RR) with a Omni-Directional Antenna and a directed Antenna on the IWLAN/PB Link PN IO's. But this is only possible if cicumstance create line of sight and the distance is not more then the 75 meter you had written. And important to know is tht you will have a delay in your signal due to the converting of the network from PN IO to Profibus and the WLAN part you have. This should be keep in mind as well.
	Best regards, INS
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8/27/2009 5:26 PM	Rate (0)
N01UNO Posts: 3 Rating: (0)	Thanks for the info INS the buildings need communication and everything is stationary. When you talk about a delay areyou talking a few seconds or less then that?I will investigate the solution that you provided and have just found out that between buildings 2 and 3 the distance is only about 10m so I think it may be better to leave the fiber optics in this spot or replace them with a profibus cable and ethernet cable.
N01UNO Posts: 3 Rating: (0)
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8/28/2009 9:11 AM	Rate (0)
INS Gold Member Joined: 4/6/2006 Last visit: 2/5/2024 Posts: 604 Rating: (56)	Hi, A delay would be something like 16 or 32 ms as we could compare it to a Profinet solution which is wired. Over a Profibus network this is hard to say this depends on the speed of the device used on your Profibus network. When it's only then 10 meter the 2nd option, with the Single Radio APwould work for you.
	Best regards, INS
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8/28/2009 1:28 PM	Rate (0)
J_Bell Posts: 5822 Rating: (412)	Hello, I am sorry for my late question but do you intend to replace the PROFIBUS as well as the Ethernet Connections? Thank you for your patience. J_Bell
J_Bell Posts: 5822 Rating: (412)
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9/1/2009 8:26 PM	Rate (0)
N01UNO Posts: 3 Rating: (0)	Hello J_Bell, Yes I intend to replace the PROFIBUS as well as the Ethernet Connections
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9/2/2009 4:43 PM	Rate (0)
J_Bell Posts: 5822 Rating: (412)	Hello, please excuse my question but this is due to the different uses you are about to havein both networks. On the one hand cyclic traffic with the PROFIBUS part and on the HMI part you have much less cyclic but more acyclic communication. About the networking itself it is really hard to recommend anything without closer knowledge about the surrounding conditions on site. My personal problem is that you want to network units within building even in between buildings. If we consider also the mentioned application ranges it might become difficult with one wireless WDS Connections. Just to remember, a WDS connection between Network parts consumptions 50 % of the possible traffic load. Personally I would use a WDS instead of a Client module like the SCALANCE W746 with Layer 2 Tunnelling, as you remember you maybe need more than just one MAC Address for PROFINET with your devices. But as said this is something which would have to be planned in detail. If you even get another step forward and you want to network even the buildings wireless... this will increase the level of difficulty dramatically. If you really plan to do it you should get someone on site to do a site survey, to find out which Wireless channels are available at your site at all. Then it is necessary to figure out where the best place is to set up the APs used and on which Bandwidth they should work at. As mentioned, just to begin with. I hope I could give you some idea what to take care about in such a situation. Best regards J_Bell
J_Bell Posts: 5822 Rating: (412)
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