Cannot ping L32E

Hi guys, I am trying to communicate with an L32E CompactLogix system that was set up a few months ago but I cannot even ping the PLC let alone get it to show up in RSLinx.

Here is my setup:

L32E 192.168.1.1 connected to switch (Allen Bradley switch, cannot remember model)
PV600 192.168.1.2 Subnet Mask 255.255.255.0 connected to the same switch.


The panelview and the L32E are connected together throught the switch and are working.

My laptop is running XP. It has a static ip of 192.168.1.10 with a subnet mask of 255.255.255.0. Firewall is turned off.

I have tried taking the switch completely out and using a patch cable to connect to the L32E but it still will not work.

I cannot ping either the processor or the PV. Those are the only things on the network as well. I am using RSLinx Classic Professional 2.57.

I have been connected to the PLC before so I cannot understand why it doesnt work now.

For what its worth, I can connect to a Controllogix RIO just fine with the same laptop.

I am in the process of getting a serial cable to see if that will allow me to connect.

Any help would be appreciated. Thanks guys.

You need to configure "ethernet devices"in rslinx.In c"onfigure driver" configure ethernet devices with your ip adress of panel view as well as plc.Then go to RS who,ethernet devices,Then you can find your devices

First, try downloading a program called Network Scanner from www.softperfect.com It is kind of like super Ping. Put a range in. Also, if you try and go from the Processor directly to your computer, you need a crossover cable. Let me know if you see anything from Network Scanner.

George

srv said:

You need to configure "ethernet devices"in rslinx.In c"onfigure driver" configure ethernet devices with your ip adress of panel view as well as plc.Then go to RS who,ethernet devices,Then you can find your devices

Click to expand...

I was under the impression that if one cannot ping the device, then there is no point in even opening up RSLinx?

I have not used the Ethernet Device driver before. I have always just used Ethernet/IP devices.

George Graziano said:

First, try downloading a program called Network Scanner from www.softperfect.com It is kind of like super Ping. Put a range in. Also, if you try and go from the Processor directly to your computer, you need a crossover cable. Let me know if you see anything from Network Scanner.

George

Click to expand...

I will try the Network Scanner first thing Monday. Thanks George. I did use a crossover cable when I tried connecting directly.

I agree, if PING doesn't work, RSLinx won't either.

If it were me, I would download Wireshark and cycle power to each device, then watch for the ARP packets from that device's MAC ID.

That's a pretty much bare-metal, low-level, no-fail method for determining the IP address of a device.

Connecting over RS-232 to browse the Ethernet interface is a good method too, at least to determine with certainty what the IP address of the CompactLogix is.

Ken Roach said:

I agree, if PING doesn't work, RSLinx won't either.

If it were me, I would download Wireshark and cycle power to each device, then watch for the ARP packets from that device's MAC ID.

That's a pretty much bare-metal, low-level, no-fail method for determining the IP address of a device.

Connecting over RS-232 to browse the Ethernet interface is a good method too, at least to determine with certainty what the IP address of the CompactLogix is.

Click to expand...

As always, thanks Ken. I will try that also Monday. I am not ruling out the laptop as a source of the problem. We shall see.

Have you tried running bootp and see if dhcp is on? When is the last time you were connected? Have you done any software upgrades? Seems strange that you can't get to the PLC or UNIT.

The panelview and the L32E are connected together throught the switch and are working

Click to expand...

His observation kind of limits what could be wrong.

Trying changing the ports on the switch. Remove the port which is connected to pv and put your cable and see if you can the PLC. Check again you static ip and subnet mask. I usually enter 198.162 instead of 192.168. Lol. Switch off wireless and let us know

The only thing that springs to mind is that 192.168.1.1 is usually the default gateway address - and using that as the L32E address may be confusing the switch.

Try setting the L32E address to 192.168.1.5 and see if the problem goes away.

In my experience, the most common reason for "I know the IP addresses and nothing is responding to PING or RSLinx" is that the actual IP addresses are different from what you think they are.

Verifying the IP addresses using ARP monitoring with Wireshark, by using the Configuration screens on the PanelView Plus, or by browsing via RS-232 to the CompactLogix Ethernet module using RSLinx Classic can all confirm the IP addresses being used by these devices.d

I've overlooked verification of the IP addresses enough times to be very methodical.

If the IP addresses of the PanelView and the CompactLogix are confirmed, you can start investigating the PC or the switch as a reason for this lack of connectivity.

daba's comment is important as well; the first address on the network is almost always the default gateway, so ideally you shouldn't use that address for a device because it is very likely that future devices will inadvertently get configured with that address as the default gateway. Many routers and managed switches also get addresses in the low range of the subnet. I often start with my controller at .10.

I just went through the same situation last week and this was my solution. the compact logix looses the ip address when you loose power.

Use the bootp program and set the ip address and then go online and drill into the ethernet port. unclick enable bootp, unclick enable dhcp, and unclick enable dns. then go offline and reboot power to unit.
if that doesn't work, use the rs232 comms port and go online and do the same thing.

regards,
james

edited due to confusing instructions.

But he says that the Panelview and the PLC ARE COMMUNICATING. So I doubt that it is a loss of IP.

Update:
Well boy do I have egg on my face!
I connected to the L32E with the serial cable. And the IP address was indeed different. I am so used to using 192.168.1.X that I didn't even notice that the Panelview was 192.168.0.2 and its program says it is communicating with a PLC at 192.168.0.1.

So with my laptop being 192.168.1.3, there was no way it could see the PLC. Changed my laptops ip address and its all working correctly now.

This also explains why the PLC and the PV were able to communicate with each other.

Thanks to everyone for their responses. Twas an ID10T error in the end but I hope my experience will help someone out there in the future.