1756-ENBT addressing

Hi. I have a 1756-ENBT/A card that went bad. I'm putting a new one in. It's giving me an address of "Bootp-00:00:bc:xx:xx:xx". I changed the card address to 10.10.10.105 offline and then D/L to the Logix 5561 and the same wrong address is still in the card. Please help! Why isn't the address changing?

On the port configuration tab, you need to set the fixed IP address and turn off BootP.

like such....?

OkiePC said:

set the fixed IP address and turn off BootP.

Click to expand...

like such....?

You can use the Rockwell Software BootP/DHCP utility, to get the module set up initially:
http://www.ab.com/networks/ethernet/bootp.html

Hook your laptop up directly to the Enet card, turn off your wireless (You might not need to do this, but for me it would mess things up)

Fire up bootp.

Look for the MAC address of your Enet card, or just type it in.

When the MAC address shows up, double-click on it and assign your IP address to the Enet card.

With the new IP address showing in the bottom window (relation list) of bootp, click "enable bootp".

Now click "disable bootp". Don't leave it enabled, or each time that you boot up your PLC (not that this should happen all that often) you will get a new IP address.

If it complains, just ignore it. It's typical for bootp to "fail" on turning off bootp.

This is mostly from memory, so if I missed something, I apologize in advance.

A basic principle: unlike PLC/SLC/MicroLogix, the ControlLogix programs don't include the configuration information for 1756-ENBT modules.

The 1756-ENBT can only be reconfigured online. Generally you'll use the BOOTP/DHCP Utility, or browse to it using RSLinx Classic over some other connection (USB, serial, ControlNet, etc).

I also ended up going into the BOOTP-DHCP Server in the Rockwell Software and putting in Subnet Mask 255.255.0.0 under Network Settings,went out of that and rebooted. Once power was back on the card showed the address I needed scrolling across the front. I then wen to Rslinx / Rswho, found the card which was in slot #15 of the backplane. I then did a right click on it and went to module properties where I also entered in Subnet mask. The IP address was already there. From there I re booted once more, and then everything was normal. Ok so what was the difference in what You guy were telling me. I really need to understand this. Thx!

The only thing different that I could tell is that you successfully turned off BootP this time (seen by the fact it shows Static in your screenshot).

Note that without a validd IP address to start out with, you may be unable to browse to the module in RSLinx in the first place, and this is the reason I suggested using the BootP utility.

Ken may be able to explain the further particulars about when and why turning off BootP may not work as expected. It usually works for me, but I have had it fail the first try, work the 2nd time, who knows, I just make sure I look two or three times before assuming it worked.

showshoka - here's the "bottom line"

An EN?T module that shows "BOOTP 00 00 BC xx xx xx" is set up for Dynamic addressing - meaning that it needs to be told its EtherNet/IP address from a BOOTP server running on the network.

BOOTP "listens" on the network for modules broadcasting their MAC address (00 00 BC xx xx xx), and can then use a look-up in a file to send the correct IP address to the module. Alternatively, you can do this piecemeal and give individual modules their IP addresses manually, and that is what has been suggested in other posts.

Some people use BOOTP to configure modules on the running plant, and it certainly works OK unless.....

1. The machine that is running BOOTP is down or not on the network. If BOOTP server isn't available, it can't set the IP addresses of the modules - simple.

2. You haven't changed an EN?T module on the plant because of a failure or any other reason. BOOTP responds to specific MAC addresses, so if you put a new module in, it won't be in BOOTP's "relationship" list - MAC addresses are unique to each module.

You certainly can use BOOTP to configure a module's IP address, either automatically (using a "relation list") or manually (by setting the port parameters yourself), but I don't think it is the easiest method.

When using BOOTP with a relation-list (automatic mode), there is no way to make this a "one-time" operation - meaning that you cannot tell the EN?T module to "remember" the IP address - BOOTP will be needed every time the module powers up.

When using BOOTP manually, you will have do do two things....

1. Wait for the module to broadcast its MAC address - double-click it, then enter its IP address.

2. Select the module again, and click on "Disable BOOTP" - this sends a command to the module to remember the IP address, which is the same as going to "Static" mode in the module.

By far the easiest method for setting a module's IP address is just to browse to it in RSLinx, and go into the "Port Configuration" tab in the module's properties.

browse to it - easy to say, but how?

1. if it has a USB port (EN2T, EN3T), then just stick it in a chassis and connect to it via USB. The USB driver in RSLinx is "Plug and Play" - it will self-install.

2. if it is an ENET, or ENBT, then stick it in a chassis you can already connect to via another module (don't connect an ethernet cable to the module). Remember you can always "browse to" the module, across the backplane, from a processor's serial, or USB port.

Once you can access the module's port configuration tab, just choose "Static" addressing mode, set the IP Address and SubNet mask as you want them, check the box to allow automatic Speed/Duplex negotiation, and click OK.

Once the module reports that it is set up to its IP address, you can be assured that it will remember those settings, so just unplug it, and use it in the target chassis.

HTH

Hi everybody, sorry to ressurect this topic, but i have a problem similar to the original one...

I have a redundant PLC system, each one with two EBNT card. One of them got bad and we replaced. But the new one had no IP configured.

So, we try to put the same IP of his pair using the BOOTP server (the one we are configuring the IP is as slave). When we put back the ethernet cable in the card, both cards displays the error "duplicate IP". If we put the IP of the slave already as the IP of the master + 1, everything works fine, but when we put the slave as the master, they don't switch de IP address (the other ethernet card pair switch the IP).

The other problem is that if we try to go to RSLinx and select the 'Static' option, when we click in 'apply' we get the following error: "An unexpected communications error has occurred. General status is 0x0009".

We also right-click on the SRM module and click in the "Module Configuration", but nothing appears.

We try connecting directly to the ebnt card using a ethernet cable. And also try connecting to the processor using the RS-232 port and the driver RS-232 DF1 drivers.

Anyone has an idea of the problem?

Thanks very much

Your issue is only distantly related to the original thread; it would have been better to open your own thread.

Some versions of ControlLogix Redundancy support automatic reconfiguration of the Secondary's Ethernet modules. I don't think v13 Redundancy did, but I'm pretty sure higher versions do.

In those versions, you must set the "replacement" module exactly the same as the existing one (same IP, same subnet, same gateway) and allow the SRM or RM module to perform the proper reconfiguration.

A basic principle of ControlLogix Redundancy is that the module firmware supported by each Redundancy Release is very specific.

The first question is "what revision of ControlLogix redundancy are you using ?"

The second question is "is the firmware revision of the replacement 1756-ENBT compatible with this version of ControlLogix redundancy ?"