VPN CONNECTION WITH RSLINX

[mmervenne 0]

Hello all, I have an application where i need to connect to a SLC 5/05 and a GE Quickpanel View at a plant in mexico. There is no computer connected to their PLC. I have never connected to a PLC with a VPN. Should I just be able to connect to their network and then use RSLinx to search for the PLC in RSWho?. how difficult is this?. Any pitfalls to be aware of?. If anyone has any articles or know where to find step by step instructions that would be greatly appreciated. Thanks Mike

[finfin 0]

How will you be connecting to the VPN? That is the first step. Next question is; do they have the same network ID?

[mmervenne 0]

From what i have read I should be able to do it over the internet. I dont have all the specifics but i doubt that they have the same network ID.

[finfin 0]

Ok. You will need to create a network connection either with your Windows network connections or whatever your customer is using for authentication software and you will have to login to thier network. After that you can use RSLinx to go directly to an Ethernet processor. If the processor that you want to get to is not Ethernet, you will have to go through some type of gateway to get to the desired network. Providing you have a fast internet connection you will really enjoy the speed as opposed to a dialup connection. Be sure that you have all of the data files etc. on the computer that you are connecting with, because you will likely not be able to access any office LAN once you connect to the remote network.

[pabeader 0]

If you are able to VPN into their ihnouse network, then you will be a member of their network. Very much like if you were sitting right in the plant down their. (expect for the weather!) As long as you have all the correct software and data files on your computer you should be able to do what ever you could if you were there. The problem is the part where you say "There is no computer connected to their PLC" Without that you won't be able to 'see' it at all. The only way to connect to a PLC like that is to plug a cable from your computer into the PLC. Until they have a connection from the PLC to the outside world (ie their inhouse network) you are stuck. Kinda like if I had a phone that wasn't plugged in. I might be able to pick it up and talk into it but, nobody is going to hear it.

[finfin 0]

Pabeader is absolutely right. I assumed that the "no computer connected to the PLC" meant that no computer was connected directly to the PLC. The PLC would have to be on or connected to the customer's network and at least be able to "gateway" to the PLC network. Obviously the electrons won't just jump over to the PLC that you want to communicate with just because a connection was made in the vicinity of the PLC.

[mmervenne 0]

The PLC will be connected directly to the network. The IT department has proposed another plan to me and i would like to get your thoughts on it. They want to install rslinx and rslogix onto their remote access portal and have me log in and access the plc from there. Any thoughts?. Thanks Mike

[finfin 0]

I have no idea on that... Would you be running Remote Desktop or PCAnywhere or what?

[BobLfoot 302]

My thoughts on RSLogix and RSLinx on a remote access portal. By having RSlogix and RSlinx running on a PC at the remote site the likelihood of things timing out between the PC and PKLC are much improved. Your local PC becomes just another display. The only drawback is that the final *.ACD or *.RSS, *.RSP file resides on the remote terminal as well. To have a copy you can play with offline you'll need file transfer capability from the remote PC to your local PC. With PCanywhere or Remote Desktop / RADMIN this should not be much of an issue. Just be sure how the Remote PC is going to behave if your connection to it is dropped. If the port does not auto release for inactivity this could be a problem.

[paulengr 44]

I've done it both ways, remote desktop as well as remote access. If there is a momentary interruption in the connectivity to the PLC and you're running RS-whatever locally, you get a hiccup and it complains, saying the connection was interrupted and asking if you want to retry. If you store the FILES remotely, boy are you in for some good old Microsoft-induced torture. There is absolutely nothing like a very poorly written network file system, and Microsoft is one of the best at being the worst. First, your PC will mysteriously lock up for seconds to minutes for no apparent reason if you have a blip (it is monitoring the file and looking for locks to manage a multi-user situation). I mean LOCKS up. You get nothing. No mouse, no keyboard, no nothing. Hopefully no blue screens of death but this is not uncommon either. Second, it will then tell you that you can't save the file anymore when you attempt to. It simply drops access in any way, shape, or form to the original file. Third, it won't let you save it anywhere else or if you try, you will just get a garbage file that is useless, if you finally manage to get control back. If you use a "remote desktop" type access, you have two issues. First off, the screen can look crappy depending on the screen resolutions involved and everything will be a bit "choppy" in terms of responsiveness. It is workable but not something you want to deal with every day. When there's a momentary packet loss or other "blip" in the network connection, it will result in "freezing" the remote PC screen but not yours. However, almost all of the above issues go away. I don't recommend Microsoft's version, but it is free. PC Anywhere is OK. GotomyPC (or gotoassist for the remotely initiated version) works about as good as PC Anywhere and has the convenience of being totally web/ActiveX based. VNC is open source so the price is very hard to compete with and on par with GotomyPC and PCAnywhere in terms of quality. My personal favorite (which also conveniently solves the remote/local file problem and has some other nice features) is hands down, Dameware Remote Control. The license fees are per USER rather than per PC. Everyone shares the same screen which can be a pain if multiple people are trying to share a single server, but it can also get you around the fact that Microsoft's Remote Desktop shows up as a totally separate login (essentially a software-based "thin client") which is usually detected by HMI software and treated as an attempt to cheat the licensing system (but not RS-Linx/RS-Logix 5/500/5000). The advantage of most of those over Microsoft's Remote Desktop for questionable connections is that if your connection is broken, the remote PC is still logged in and showing the same screen. Microsoft's thin-client based version boots you off the machine (forced logout). I have had numerous problems with Checkpoint software's VPN, mostly involving locking up machines after about 20-40 minutes. There was apparently a memory leak. The latest version is fixed and I've had many fewer problems. I'd recommend going with an open source solution instead of this particular proprietary one (bugs get patched quicker). ...so, as a programmer, having a local copy of RS-Linx & RS-Logix 5/500/5000 with LOCAL copies of the programs is by far the best setup. Failing that, remote desktops are very nice. Some are nicer than others.

[Nathan 7]

-Running RS-x locally should be really smooth. As stated above, you address the PLC (or RSLinx Gateway) via TCP/IP as you would if it were on your LAN. Microsoft file sharing does suck, but it's not as bad as stated. -Microsoft's old terminal services was pretty crappy, but they've done a lot to improve performance. I used to recommended VNC over it, but more recent versions of Remote Desktop work really well - they don't transfer the mouse cursor, wallpaper, etc like others necessarily do. A disconnect does not screw you. Remote Desktop will resume your session on a reconnect. I'm also a fan of Dameware, but you should know that most antivirus programs recognize it as malicious and go crazy. It is best for slipping in on computers that you didn't setup beforehand for remote access. -I agree that GoToMyPC is a nice service. Very convenient and it has a builtin file transfer utility (that temporarily disables control). For the record it runs Java, although they do have an ActiveX wrapper to help install Java if the correct version isn't installed. Many IT departments block their site for security reasons. Edited 3 Apr 2007 by Nathan