Compactlogix L35E. EthernetIP module lost and cannot see it

Hi all,
I am an amateur PLC user. I am using a Compactlogix L35E.

Some time in the past week, the I/O light began blinking green. Whereas previously it was solid green.

When i attempted to communicate with it over the LAN, i could not establish communication with the PLC. So i connected using an RS232 crossover cable.

I am able to communicate, go online, modify routines, download new programs, upload exising programs, using the RS232.

This said, my RSLinx is not able to see the Ethernet IP module. My RSLogix 5000 is not able to see the module. There is a Yellow fault symbol above sitting abovewhere the Ethernet IP module is represented on the backplane, found along the side panel of RSLogix.

I am currently running V16 Firmware.

I would appreciate any ideas as to how i can re establish communication.

Ryan

Hover over the errored device to look at it's IP address.
Once you are on the same local network, try pinging it. Is the ping working? If not, then the issue probably resides with the device's IP settings, or hardware failure.

I think the 1769-L35E had a literal physical Ethernet daughtercard connected to the main board, which works logically like a separate module in the controller's backplane.

It's *possible* that has failed mechanically or electrically, but I would expect a flashing Fault LED, not just a blinking I/O LED and loss of network connectivity.

Can you post a screenshot of the I/O tree visible in RSLogix 5000, and how the backplane looks when you bridge through the RS-232 port in RSLinx Classic ?

Ordinarily you can "see" the daughtercard in RSLinx and right-click to configure its Ethernet configuration and IP address.

Also do basic network connectivity troubleshooting: get a known-good Ethernet cable and plug the controller's network port into a known-good Ethernet switch and observe the status of the link LEDs.

Thank you Pre. As i am not able to "see" the network card using RS232, i am not able to configure it. Nor am i able to see its network address. pinging the last known address does not work.

Hi Ken, I have attached 2 images.
One image is of the RSLinks file tree. The other image is of RSLogix backplane. I am not able to see the network card in the RSLinks. The RSLogix shows an error.

Previously i had an RSLinks file tree for the Ethernet/IP module. But i removed it and attempted to reinstall it as a troubleshooting method. Unfortunately not successful.

I am thinking, should i consider a factory reset for the PLC? If i remember correctly, it involved removing the battery and reinstating the battery? But this does not sound right as i have a compactlogix L32 that operates without a battery. I only need to download the program again in the event of a power loss. I do not need to reinstall any firmware.

Hey Ken, I usually have an ethernet cable, (working) that is connected between the PLC directly to my modem. Previously i communicated to the PLC via wifi in the way. When there is communication, there is usually a flashing (like a flashing modem light, not a blinking periodic light). Currently, when it is plugged in, there is no light. I also attempted to plug a known working crossover ethernet cable between the PLC directly to my PC. Previously there was a flashing light, (not blinking light). Currently there is no light. It is as if my ethernet card has gone to sleep and it won't wake up to join the party

I don't have a 1769-L35E handy to examine, but my recollection is that it was single-board controller with a very full double-sided PCB, with the Ethernet and Serial connectors and hardware on the left side and the CF socket on the right.

So the controller's backplane was "virtual", not physical. The CPU is Slot 0, and I think the Ethernet module is Slot 1, and the 1769 I/O bus is Slot 3 (according to RSLinx). I'm not sure what's supposed to be Slot 2.

When you're online with the controller over the RS-232 port, you should be able to select items in the I/O tree in RSLogix 5000 and see a status value in the bottom of the I/O tree pane. Sometimes that gets collapsed all the way and you have to drag the separator up from the bottom of the pane with the mouse pointer.

I expect that to give you some kind of "disconnected" or "faulted" notice about the Ethernet module.

I would be very surprised if a user program reload or even a firmware flash remedied the problem; it sounds to me like a hardware failure.

If you have a CompactFlash card fitted, you could save to CF card and reload from that after disconnecting the battery and cycling power; the CF card holds the firmware and the user program.

Or, you can settle down with the serial port and try to reload the firmware that way. Don't trip on it when you get up to grab another mug of coffee like I once did, making a lovely L35E paperweight.

Attached pic: the status window you should see when you select the daughtercard in RSLogix 5000 (empty, of course, because I'm offline).

Hey Ken.
Thank you for your response. The picture you attached is the exact picture i usually see on the backplane.

Good news. Today i decided to install an additional array of relays to my system so i needed to turn the power off at the source to prevent any accidental 24V shorts from the 24V power supplies. And guess what happened when i turned the system back on... Yup... ethernet module woke up.

When i think about it, this is actually the first time since the ethernet module went beddy byes (4 days ago) that i have actually power cycled the PLC.

When i contact my ISP for tech support they always ask me to power cycle my modem. And the response i have in my head is "Of course i did. I am not an idiot!".

Well apparently... i am an idiot.

Thank you again for your help. I was actually thinking along the same line as you. That this was a hardware failure. Thank god it was not as this is a very expensive hardware failure.

As a hobbiest, i do not have a company paying for my toys. So this would have been very financially painful.

For now i would say this thread is ready to be closed, but i might reopen again if my ethernet module takes another nap.

Take care,
Ryan