CompactLogix flashing red ok, with a couple twists

The other thing w/ BOOTP, I've never had much luck disabling it via the utility. I just set an IP and then use RsLinx once I can connect to force it over to a static address instead.

Me too.

Also: if I'm trying to set an IP address of a device (Ethernet card, etc) as 192.168.1.10 (for example), then I make sure my computer/laptop IP address is Static and set to 192.168.1.XX beforehand.
 
The other thing w/ BOOTP, I've never had much luck disabling it via the utility. I just set an IP and then use RsLinx once I can connect to force it over to a static address instead.

One thing I read in a RA Technote the other day and worked for me is that sometimes the normal "Disable BootP" Button doesn't work, but that going to Tools -> "Disable BOOTP/DHCP" works.

BootP.PNG
 
One thing I read in a RA Technote the other day and worked for me is that sometimes the normal "Disable BootP" Button doesn't work, but that going to Tools -> "Disable BOOTP/DHCP" works.

Interesting, I will have to try it
 
George,

I knew all that about BootP, I just meant that I thought the IP address was actually ASSIGNED when you disable BootP. Like when you assign the IP address in the relationship list, it's not actually SENDING the IP address to the PLC, just setting the relationship in the BootP software, but when you send the command to disable BootP it assigns the IP address TO the PLC at that time as well.

That was my assumption, but I will have to check Linx next time I'm using the tool.
 
LoganB said:
George,

I knew all that about BootP, I just meant that I thought the IP address was actually ASSIGNED when you disable BootP. Like when you assign the IP address in the relationship list, it's not actually SENDING the IP address to the PLC, just setting the relationship in the BootP software, but when you send the command to disable BootP it assigns the IP address TO the PLC at that time as well.

That was my assumption, but I will have to check Linx next time I'm using the tool.

Geospark said:
...leaving it enabled will have no effect on the device's ability to start using its newly assigned IP address. After the IP address is assigned, you can immediately go to RSLinx Classic and start an Ethernet driver and browse to the device...

Or, you could just believe me?

If not...

I've done a quick run through on assigning a MicroLogix 1400 a new IP address via BOOTP Server so as to demonstrate what I have explained and know to be true...

When you first see the client device requests automatically appearing in BOOTP Server under the Request History, by displaying its MAC address (forgot to stress that in last post for you Ron - you don't have to get it and manually type it in), the client device is BOOTP enabled and sending UDP requests to the Server. It does not yet have an IP address assigned. Once you select the entry and assign the IP address, BOOTP Server will immediately send a command to the client device, assigning it the IP address configuration. You can see confirmation of this command being sent by viewing the Status at the bottom of the window. The new relationship between the software and hardware can also now be seen in the Relation List. Once the device has been assigned the IP address, it will reply, once more, to BOOTP Server, declaring its MAC address and new IP address. It will not send any further requests or declarations...

01_BOOTP_Enabled%20-%20IP_Assign.bmp


The Request History is now static as the last entry was the client device declaring its new configuration to BOOTP Server. BOOTP is still enabled at this point.

Viewing the LCD display on the MicroLogix 1400, we can observe that the ENET Cfg Status shows the new IP address has been assigned. In RSLinx Classic, we can now browse through an Ethernet driver to the controller at the assigned IP address (no pictures, but you believe me, right?)

With BOOTP Server left running, and the new Relation List entry still present, we now reboot the controller. As BOOTP is still enabled, the IP address is cleared from the controller's memory and the client device once again sends a UDP request to BOOTP, which includes its MAC address. Because the Relation List entry is still present, BOOTP Server will know which IP address to automatically assign to the device MAC address in the UDP packet request. Therefore, the controller is automatically and immediately reassigned the same IP address as before the reboot...

02_BOOTP_Enabled%20-%20Reboot%20%2B%20Reassign.bmp


Note the intentional time delay I gave there to show no further requests had come in for several minutes before the reboot. Once rebooted, and the same IP was reassigned, the controller once again declared its new IP address configuration, and then the Request History was once again static.

Next, we delete the Relation List entry so that BOOTP no longer knows which IP address to assign to the client device MAC address...

03_BOOTP_Enabled%20-%20Delete%20Relation.bmp


Then, we reboot the controller once more...

04_BOOTP_Enabled%20-%20Reboot%20%2B%20Request.bmp


Here, we can now see that the client device is once again sending UDP requests to BOOTP Server in the Request History and that it cannot automatically service those requests as there is no existing Relation List entry.

After several unserviced requests, we once again assign the IP address configuration and can see both the Status confirmation at the bottom and the client device declaration of its new IP address in the Request History. The entry is also now present again in the Relation List...

05_BOOTP_Enabled%20-%20IP_Reassigned.bmp


All the above is carried out while BOOTP remains enabled.

For good measure, we now disable BOOTP -

First, we go online to the controller in RSLogix 500. We then open the Channel Configuration > Channel 1 tab (ML1400) and we can see that BOOTP is still enabled. We can then close the Channel Configuration dialog for a moment but stay online to the controller.

Back in BOOTP Server, we select the device entry, that is - any entry which includes the MAC address of this device, be it the declaration entry in the Request History with the IP address, or any previous request without the IP address, or the entry in the Relation List, it does not matter. Any reference to the device MAC address will point to the controller. Then we select Disable BOOTP/DHCP. Under the Status we can then see [Disable BOOTP] Command Successful (many users struggle with this feature)...

06_BOOTP_Disabled.bmp


We can then go back to RSLogix 500, which is still online, and once again open the Channel Configuration > Channel 1 tab and now we can see that BOOTP is disabled. We can enable and disable it at will, and the Channel 1 tab will reflect the change each time.

Argh, punching out time again. Apologies as today I have now also not gotten around to addressing the issues at hand in the thread.

Tomorrow is possibly possible but often probably improbable? :oops:

Regards,
George
 
Last edited:
I try never to just "believe" someone on principle. Faith causes a lot more problems than it solves. There could be something abnormal with my setup that causes me to have different results, so just believing you wouldn't do me much good if I waited until I was under the wire to assign an IP address with no other option than the BootP utility.

I didn't mean to suggest I thought you were wrong. I would just like to slap eyes on my own work station and give it a shot to make sure *I* was wrong :)
 
..and I was just joking! :nodi:

I think I need a new keyboard or something? My intentions keys are really on the blink of late? :unsure:
 

Similar Topics

I have a CompactLogix 1769-L18ER-BB1B that was power cycled a few times and had a mechanic pull the memory card with power on and re-insert it. At...
Replies
26
Views
8,355
Absolute newby here. Also new to PLC. But I am a seasoned Electronics and Computer Tech. Helping to get my buddy's machine back up and running...
Replies
3
Views
2,111
When I came in today one of our machines would not communicate between the HMI and the CompactLogix L27ERM QBFC1B. I cycled power to the machine a...
Replies
2
Views
6,912
Hello again. I need to flash a CompactLogix L32E from firmware ver15 to 16. It has several Panelview Plus's Series D Rev A, connected via...
Replies
16
Views
2,749
Hey guys, I'm super new to troubleshooting PLCs and was hoping I could get some guidance I've got a machine I'm commissioning and it's kind of a...
Replies
27
Views
10,306
Back
Top Bottom