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Remote access with step7

Created by: Ssc_Mikro at: 9/8/2008 10:12 PM (5 Replies)

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9/8/2008 10:12 PM	Rate (0)
Ssc_Mikro Posts: 196 Rating: (12)	One of the ways to do remote support is to use a vpn client installed locally on a PC. But one of the disadvantage with this, is the information about the customers networks is shared to many employers in the office, and if one employer is stopping on the job, action on the accounts must be taken for each vpn access there is to customers networks. Of course it is a simple task if there is only one customer that has to change account setup. But if the are many customers this can be a nightmare….. But a better way is to allocate an IP address array to use for remote access, where each IP address represents a customer PLC. So if I want to access a plc from the office I just use this Nat address our Network administrator has provided us with. At my home I just access the office though a VPN Clint, and there is access to all the customers PLCs. Advantage with this solution is that network information, setup of VNP routers and keys is done by the Network administrator, and when an employer is stopping on the job, the VNP and network account can be disabled in one operation. Without any disturbance for the customers. The disadvantage with this is the way the Step7 handle access to remote network with when the IP address is NAT address. A way to solve this, is to insert a extra CP card in the hardware configuration that contain a address from the address array to use for remote access, then the plc can be access without any problem. But the customer has to accept the EXTF led is on. Is it possibly to NAT access a network without inserting a CP card in the HW configuration , or can the EXTF led be turned off from a special SFC… Profibus node can be disabled whey not modules located in the racks
Ssc_Mikro Posts: 196 Rating: (12)
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9/9/2008 12:02 AM	Rate (0)
J_Bell Posts: 5822 Rating: (412)	Hello, to tell you the truth... I am not sure what your question is all about... but I try my very best... The first part of your post seems to me to be taken from somewhere, may you provide us the information where you took this from? Regarding your question about the NAT I will try to find an answer. Well, most commonly used NAT Router do not provide a direct relationship between the Public and the Private side of the NAT. So you do not know which partner is located behind which Port of the Public IP. So if you want to access one Partner you may have a Problem, because you do not know where to go to. A simple Solution for such an issue would be to use Port Forwarding. In this case you may access at least one PLC behind the NAT Router... but not whole networks. The Port102 is used only once.... and not more often. Personally I think a VPN is still the most efficient solution... but maybe someone else has a better solution to tell. Best regards J_Bell
J_Bell Posts: 5822 Rating: (412)
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9/9/2008 7:09 AM	Rate (0)
aikona Posts: 487 Rating: (36)	Hi Another option ( maybe) is to use VPN and remote desktop to connect to a central PC at the workplace , this PC is then used to connect to the PLC's.Each user has is own user account ,if one leaves then delete account. To connect to customers it may be a bit more difficult .You use a call-back kind of system .You call the client via telephone and he switches on the modem or the internet connection. Speaking under correction you could use a scalance X .Have a look at the this link there is a lot of info on connecting to PLC via networks Greetings Eric
aikona Posts: 487 Rating: (36)
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9/9/2008 8:22 AM	Rate (0)
UMENCHO Diamond Expert Joined: 3/21/2006 Last visit: 11/1/2024 Posts: 10229 Rating: (1181)	aikona Hi Another option ( maybe) is to use VPN and remote desktop to connect to a central PC at the workplace , this PC is then used to connect to the PLC's.Each user has is own user account ,if one leaves then delete account. To connect to customers it may be a bit more difficult .You use a call-back kind of system .You call the client via telephone and he switches on the modem or the internet connection. Speaking under correction you could use a scalance X .Have a look at the this link there is a lot of info on connecting to PLC via networks Greetings Eric Hi Eric At the moment I use this type of connection. With Remote desktop (RealVNC) with PC in office we can connect to each PLC, of course together with VPN. Dissadvantages - must install all software + license . . Maybe better is to use VPN with SCALANCE s602. , yes of course need CP, connected to CPU. regards

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9/9/2008 1:25 PM	Rate (0)
Ssc_Mikro Posts: 196 Rating: (12)	Hi J_Bell Maybe my written English not the best , but if youpaste the contents you don’t understand I will try to formulate it better. Regarding the NAT is of course the IP address must be fixed, I can see I may have misunderstood NAT/ Port forwarding. But it still laves the question about access the plc from Step 7 if you’re not connected directly to network, with an VPN client. The best solution was If you could enter an alternative IP address in step 7 if the PLC could not be reach with the IP address from the HW configuration.
Ssc_Mikro Posts: 196 Rating: (12)	Last edited by: Ssc_Mikro at: 9/9/2008 1:25 PM
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9/10/2008 12:32 AM	Rate (0)
J_Bell Posts: 5822 Rating: (412)	Hello, I am sorry, maybe the steps are a bit too far for me therefore it might be that my answer posted here may leave to discussions too. Well, first of all, it is no problem to enter any IP Address in STEP7 to load a HW Config or NetPro, even if you enter any other IP in HW Config you may be albe to monitor functions or blocks or even DBs. But the issue is the VPN. As far as I know you only access one network over a secured VPN. If the second Network has another Router you should not be able to use this because there is no RIP or any other Router Interfacing between these used Routers and so you have no Routing function over these. So lets imagine, if you try to access a Network with the Netaddress A and you are in the Network with the address B you can access A but if B is connected to C, D or E, you are not able to access these. Your PC only knows one Gateway, the local one. I am not 100% sure, but I think accessing a Network with NAT that forwards this information with VPN... I do not think that this will work... but maybe I am wrong... Best regards J_Bell
J_Bell Posts: 5822 Rating: (412)
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