Access Point Trouble

Hey guys, I'm having a hard time hooking up my router to this PLC. It is a AB Logix5562 and a Linksys WRT54GS Router with DD-WRT drivers.

I have hooked it to other PLCs before with no problems but I can't seem to figure this one out and I think I've tried everything!

The IP for this line is 191.168.240.1 (hence 191, not 192). I have the router setup to DHCP/Access Point/Gateway of 191.168.240.150. My laptop is set up for DCHP Automatic IP.

I've tried setting the router IP to 191.168.1.1, 192.168.1.1, 191.168.240.1, 191.168.240.150 all with no success. I've tried with and without security, changed the broadcasting name, tried Static IP instead of DHCP. Nothing worked.

I was under the assumption when you set the gateway to say 191.168.240.150, when a client connects it will give them an IP starting at that range. That is not the case here, if the router's IP is set to 192.168.1.1 it will give me a 192.168.1.xx IP even with the gateway set.

Thoughts?

Router ip has nothing to do with DHCP settings. You should see a separate area in the router for DHCP settings. You can set the range of ips and how many are given out.

gmferg said:

Router ip has nothing to do with DHCP settings. You should see a separate area in the router for DHCP settings. You can set the range of ips and how many are given out.

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On some routers the dhcp server will pick the range of addresses in the pool from the same network as the router local ip. In your case the gateway can be 0.0.0.0 Set the router local ip to the address on the network you want to use.

Already tried that but with no luck cheldon.

From your picture, your Communications appears to be working, or you wouldn't have gotten that far. I'm not familiar with Safety PLCs, but that may be your problem.

Stu....

No, still won't let me "Go Online" and in RSLinx everything has a red X over it.

First things first, are you able to ping the PLC?

Open up a command prompt and type "ping 191.168.240.7" and see if you get a reply.

If this doesn't work then your network settings are not correct. If you get a reply, then check the following.

Go to the "Configure Drivers" window in RSLinx and double click on the AB-ETHIP driver that you are using.

Check to make sure that it is browsing local subnet and through the correct network adapter.

Scroll down on your first picture where it says "Start IP Address." This is what it will assigned. If you want a 191.168.240.xx, change your router's local IP address to 191.168.240.1. Gateway can be 0.0.0.0.

I see a couple of potential problems.

You show the router's IP address as 192.168.1.1 and your are trying to communicate on the 191.168.1.0/24 subnet using the Ethernet/IP driver (AB_ETHIP-1. The Ethernet/IP driver uses broadcast messaging to see who is listening. Broadcast messages typically don't cross from one subnet to another. Try assigning your router in the 191.168.1.0/24 subnet.

Or you could use the Ethernet driver (AB_ETH-1). This requires you to configure all the IP address of all hosts used in the project in RSLinx but it does work across subnets.

Thanks for all the help guys, but I finally figured it out. All of this confusion for something so dumb... I had my router plugged into one (of the 12 in this panel) switches that was not linked to the network.

All the other 8 port switches are linked together via ethernet cable, except for one. Simply moved my connection to the next switch and was golden.

Below you can see my stupidity.

Thanks for sharing. It's not always easy to admit when you do something silly, but there are so many opportunities in our field to make simple mistakes.

On the bright side, at least it wasn't a DH485 port you plugged into by mistake!

How can you know from looking that a switch is not linked? I would probably put a tag on it that warns the next fellow.

Lancie1 said:

How can you know from looking that a switch is not linked?

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It would have been a fifty fifty shot for me, looking at two open ports.

That is one heck of a lot of i/o networking going on it appears! Got enough devicenets in there, do you?!

I retract my previous post, it wasn't something silly. fifty fifty shot.

Automotive assembly line. That is just one of 3 cabinets on this body-side line, if you seen the rest of the cabinet you'd sh*t.

Yes it was a 50-50 shot, just plugged into the first port I saw open. Unfortunately not the right one!

Good idea Lancie1, thanks.

Dude you got a hot mess there. I would be questioning the skills of the system designer.

You should be using a 24 or 48 port switch in that panel or at least stratix 8000 with 26 ports per switch and max expansion units.

This setup will be a PITA if you ever have a port go bad. It will be a nightmare to troubleshoot.