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--US GUYS-- 3G Telecom Availability in remote US - Plant Remote Access

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DrDrreeeaaa

Electrical
Apr 25, 2008
266
Hi All
I'm after a solution to remote access to a regional US plant from Australia. The plant is ControlLogix based. The logix has an ethernet/IP card and this is the proposed plug in point for a modem. We need to get online to the PLC HMI etc and monitor etc.

Ideally the black box we need will have ethernet one one side and the wireless link on the other. If anyone has any suggestions on the hardware that would be wicked.

Now here's the catch.

We want the link to the plant to be over a 3G network.

My main problem is coverage - the plant is remote, and I have looked up 3G coverage in the states - it looks pretty grim - but it's hard for me to make a judgement from that info - most of it is wrt the iPhone, I read that 90-95% of the US has no 3G coverage while 85% of populated areas do have coverage.

Can anyone help me out? It's hard for me to get a feel for the network coverage from way over here in AUS. US guys who implement remote plant access over wireless... what do you use? Do you have experience with 3G network coverage? is it reliable in remote areas of the US? is it a complete joke?

 
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I have no sites that are supported by 3G network.

It is always supported by the PLC connected to the plants ethernet backbone network. Then we usually have VPN access to the site. Cisco Systems VPN Client Version is what I use most of the time.

A more secure way, you can have a server at the plant with the plc software on the server and use remote desktop to access that server. Log onto the server bring up the PLC software and your online with the PLC. This is also where you have an ethernet network.

We never use those cipher keys to get a password, they are a pain if you have a large customer base. If the customer's IT department is smart they will validate your password for a certain length of time.

I have used those laptop USB or PCM type cards to log onto my work networks. I have never seen anyone try and use these with a PLC ethernet card. They are nice but I would think your paying for cell coverage and the additional cost of the card. I would think it would be the same for 3G coverage.

You can use those wireless radio modems to get the plc to an ethernet hardwired system nearby. They can go miles with good coverage.
 
Try either an Airlink or Digi CDMA or GPRS modem. Thay are avaialble with an ethernet interface amd can be reached over the internet. Not terribly secure though.

Are the devices already on the plant's local netowrk? If so, were you going to connect over a separate IP conneciton or try to get onto the same network?

What we so, in the situation where an outside entity needs remote access like this, is we create a Citrix account for the remote user. When the user logs in, they only have access to teh devices they need to see.

Same can be done with a VPN account. This provides security, and manageability for both ends.
 
3G coverage is extremely spotty outside of major cities. I would not make it part of my communications plan in the US for the foreseeable future.

 
Yeah so I've read. The stat I have is that 90-95% of the US has 3G coverage, while 82% of populated areas are within a coverage zone.

I shall recommend that 3G for access to remote plant access in the US would be useless.

Thanks all

mb
 
Oops, in the last post I meant 'The state I have is that 90-95% of the US is outside 3G coverage'
 
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