Sign in to follow this  
Followers 0
93lt1

Ab ethernet/ip

10 posts in this topic

I have a Micrologix (net-eni) and a PV 1000 ethernet conected and working. I have another network, SLC 5/05 with 4 Enet PV's. I have tried to connect the two 'nets but In RSLinx, I cant see across networks(I cant be plugged into one switch and see anything on the other one) The first (micro) network IP address are in the 199.46.191.246, my laptop is in this range. the second network is in the 192.168.0.10.

Share this post


Link to post
Share on other sites
When you want to talk to two subnets at the same time, you have to have multiple network cards, one for each subnet. Hopefully your OS and laptop hardware will be accomoding for another network card someplace (either PCMCIA slot or, if you have W2K/XP you can use a USB network card if your PCMCIA slots are taken).

Share this post


Link to post
Share on other sites
This is kinda what I was thinking........My option would be: change all plc's and PV's to be within the same subnet, and make sure that my laptop is within that subnet?

Share this post


Link to post
Share on other sites
What you've described, LT, is two logical subnets running on two linked physical subnets (two Switches, right, connected through their Uplink ports ?) For example (I'm guessing about the IP addresses you have) Network 1             Network 2 199.46.191.246      192.168.0.10 199.46.191.245      192.168.0.11 199.46.191.244      192.168.0.12 These are both called "Class C" IP networks, in which the first three octets identify the network, and the last octet describes the node itself.   Your IP networks, "199.46.191" and "192.168.0" are logically totally separate.  Although the switches are linked together, your PC is a member of Network A and simply cannot communicate to a node on Network B directly. In order to communicate between two networks, you need a Router or a Gateway. Here in my office, and I suspect also in yours, you have a server computer (An HP NetVista running Novell Netware) and some Ethernet hubs locked away in a closet with the Internet connection, the phone wiring, the on-hold music player (remind me to take out that Back in Black CD), all guarded by a mean IT person and a cheesy lock.   Also in that closet is the magical "Default Gateway", in my case a function of the Netware server computer. This Gateway lets my traffic from the local office (10.82.91.101 is me, .104 is my neighbor) get to other offices of the Company, as well as to the Internet through a proxy.   Therefore, my PC's TCP/IP setup is configured for that Gateway computer's IP address (in our case 10.82.91.1) to be my "default gateway". When I ping my neighbor (hi, Tim) the packet goes right to his PC and is recognized there because we're on the same subnet.   When I ping "18.187.0.208 ", which is not on my network, my computer knows that it needs to send that as a routed request to my Default Gateway machine, which will route it through the proxy and out to it's destination. But between your two networks is not a Gateway or Router, rather just an uplink port from Switch to Switch. So, how to get this working ?   The simplest thing to do is to assign addresses to your computer, the Net-ENI, and the PanelView which are in the 192.168.0.xxx subnet. The next simplest thing is what our friend kkarr suggests, installing an extra Ethernet adapter in your computer to talk to the other network. The more permanent thing is to install a Gateway or Router on this network.    For example, I brought my Linksys BEFSR41 (consumer-grade router for cablemodem use) to the office and set it up in my cubicle.   My computer, and all my harem of SLC, PLC, Logix (grunt, puff, grunt) controllers are 192.168.1.101, 102, 103, 104.... but all my system administrator sees is my Router, pretending to be 10.82.91.101, little old unobtrusive, non-bandwidth-thrashing personal computer.   Pretty handy that when I do Ethernet performance tests her intrusion monitors don't go wild, too. One thing that complicates stuff somewhat is that one of your subnets has chosen non-routeable addresses.   Addresses in the 192.168.x.x network range are not supposed to be able to communicate outside their subnet.   My little Linksys router manages it through a trick called Network Address Translation (NAT) but it might not be workable for you. As a practical matter, what I do when moving between Ethernet subnets is just change my computer's IP address when I move between those subnets.   In Win95 I have to reboot, in Windows NT I really, really have to reboot, but in Windows 2000 it's mostly painless.    If I had to move around a whole lot, I'd buy a USB/Ethernet interface and let it do that dirty work for me.

Share this post


Link to post
Share on other sites
Man, did I take too long writing that or what?  You leapfrogged me twice.  :D As a rule, yes, PLC's and PanelViews will work across subnets that have a Gateway between them.  When you set up the automation device you tell it the IP address of the Gateway. I have had a user suggest that the 1761-NET-ENI has trouble sending e-mail to a non-local mail server, but I haven't verified that.   As far as I know it's regular EtherNet/IP traffic works fine across a Gateway.

Share this post


Link to post
Share on other sites
You know, when I made my previous post, I don't know why I didn't think of the router...must have been a long day or something.  Thanks Ken.

Share this post


Link to post
Share on other sites
That was a good reply......I will be attending an industrial ethernet networking class in April, I'm just jumping in a little early. This all makes sense. I think I will just change the nodes of my micro and PV to be in the 192.168.0.x range. If I buy a PCMCIA ethernet card can I assign it an IP and not effect my office network IP for the built in Enet port? What will be the max # of devices (PLCs PVs and a very few PC's)that I can have before I need to set up a gateway? I actually tried changing the IP address of the NET ENI. I couldnt get the software to talk to it, but on the original installation I had no problem. Is there any additional steps when configuring a non-default NET ENI??? Thanks very much!!!!!!

Share this post


Link to post
Share on other sites
In your "non-routeable PLC subnet", which is a Class C network, you can have up to 255 nodes. Those "octets" between the dots in an IP address are in fact just decimal representations of 8-bit values (get it, octet ?) therefore the values can be from 0 to 255. 192.168.0.0 192.168.0.1 192.168.0.2 .. .. 192.168.0.254 192.168.0.255 If you want to read the official word on this: http://www.ietf.org/rfc/rfc1918.txt If I was in your place and I was running Windows 2000 (or 98 or ME, anything with full USB support) I'd get a USB/Ethernet converter instead of a PCMCIA one.  The cost is about a draw (more than $50 USD and you're spending too much) and I think the USB plug is more robust than the tinny connectors on many PCMCIA cards. As far as the Net-ENI, try different data rates, and make sure that RSLinx isn't taking up your serial port (I think the Net-ENI serial utility defaults to 38400 kb, but the Net-ENI is often at 19.2 kb to match a PLC).   I seem to recall that the Net-ENI utility uses it's own driver, not RSLinx... I'll have to check that to be sure.

Share this post


Link to post
Share on other sites
This is perfectly legitimate no matter how you add a second Ethernet NIC to your computer.  I would leave your company connection as a server assigned IP and assign a static IP in the range of 192.168.0.xxx. BTW, 192.168.0.xxx is an international test network assigned for exactly what you are doing.  No router in the world will pass packets from this network out to the internet.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now
Sign in to follow this  
Followers 0