Issues connecting to SU2200NET over serial

[Anonymous user]

I'm trying to reset the IP on a SU2200NET with a 9619 management card.  It has one (the light is solid green), but it's nowhere on our network, so I'm trying to reset it to an IP of my choosing.  We do have DHCP, but it's definitely not getting an address from there (I've checked about 20 times in a variety of ways), and I want it to have a static IP anyway.

From what I can see, the only way to reset it is by connecting via serial.  So I'm connecting it to a machine using the 940-0024 APC serial cable.  I've tried a variety of terminal commands/programs - cu and screen in Linux, then switched to a Windows machine and tried putty and simpleterm - and no matter how many times I press enter I don't get a login prompt.  I used the following settings:

• Bits per second:  9600
• Data Bits:  8
• Parity:  None
• Stop bits:  1
• Flow Control:  None

I also tried a number of different baud rates, especially making sure to try 2400, as that was the other one I was seeing people say sometimes worked.  No change.

As an experiment, I installed Powerchute on the system, and sure enough, it recognized that there was an SU2200NET connected to COM2.  So theoretically it's there and talking.  But I just can't get any terminal to give me a login.

Anything else I can try?  Thank you!

[BillP]

Hi Allison,

By default, AP9619 and also this model of UPS operate at 2400 baud rate. The user can change that on the network management card side though.

Let's assume it is at 2400. Make sure scroll lock is not on on your keyboard. That could cause this issue. You could try re-seating (power cycling) the management card in the UPS slot. It is okay to do this while the UPS is on. The COM port being wrong or incorrectly selected is the next most common thing but it seems like you're aware of that already.

When you did the PowerChute test, it recognized something on COM2 via auto-detect?

[Anonymous user]

Hadn't checked scroll lock - that's a new one on me!  🙂  Sadly, I've now confirmed it to be off (it probably was before, but I couldn't swear to it) and no change.  I've already re-seated the card.

Powerchute did auto-detect the UPS, including the correct model number and everything, and said it was on COM2.  (But I have been trying everything on COM1 as well, just to be on the safe side.)

[BillP]

Hi,

Remove the AP9619 from the UPS and test the serial connection using Putty. The baud rate should be

• Bits per second:  2400
• Data Bits:  8
• Parity:  none
• Stop bits:  1
• Flow Control:  none

Once the connection opens you can test comm by entering Capital Y. the UPS should respond with SM which means the UPS is in smart signaling mode. If you enter capital A all the LEDs should light up and the UPS will emit a single beep along with reporting OK on the screen. Typing capital R will cause the UPS to display BYE. 

If that works reinsert the AP9619 and test connection again. 

[Anonymous user]

Neat - hadn't seen that before!  Honestly hadn't occurred to me it would respond differently with or without the card.  Sorry...:-(

Works just like that (screen responses, beeping) without the card in.  Put card back, and now back to getting no response to hitting enter (or to any of those commands, though I don't know if they're expected to work with a card in).  Tried with and without the ethernet cable in, in case that made a difference.

[BillP]

I would make sure to try all of the baud rates here: 2400, 9600, 19200, 38400, and 57600 bps

I know you tried 2400 and 9600 already so I'd double check to see if the management card responds to any of those.

Do you have another UPS or another NMC? You could try to rule one out to know if there is a problem with the NMC or the UPS to NMC smartslot communication.

[Anonymous user]

I was able to physically shuffle things so I could perform an interesting little experiment.  After moving things a bit, I was able to try the serial cable on our other SU2200NET also with a (configured through the IP config wizard in this case and working perfectly) 9619 NMC.  The exact same thing happens.  With the card in, the terminal shows no response to anything entered.  With it pulled out, it responds to the Y, R, etc... commands perfectly.

So - this seems to have ruled out an issue with the original UPS or card or the connection between the two, since it's happening on completely different hardware.  But theoretically it's not the serial cable, since the connection works fine without the card.

Also tried holding in the reset button on each card.  Both have same behaviour - they respond to enter with "NA" for the first 30 seconds or so, and then with nothing after that.

Super confused now...

[BillP]

Hmm, I agree. Did you try the different baud rates with the card in the UPSs? That could be the issue still and would make sense.

Also, you can force a baud rate via telnet/ssh on the working card. Here is how, you could try to set it to 2400 and test on that card that is accessible if you wanted:

APC units can be forced to a baud rate at the username and password prompt. If you are having an issue connecting, try setting the baud rate to a different value:

Username: 
Password: -

This example will set the baud rate to 2400 bps, using the default username and password:

Username: apc
Password: apc -2400

Holding the button on these doesn't do anything n these older cards, it probably just rebooted the NMC and also allowed passthrough communication to the UPS that gave you the NA response.

Lastly if the NMC likely has an unknown IP at least within your network scheme and you know that much, you could still try to search the IP range through the Device IP Configuration Wizard tool and see if it comes up. Similarly, maybe do a crossover network connection to the NMC from a PC and run wireshark/packet capture to see if you can figure out what the IP is through there?

[Anonymous user]

I tried the different baud speeds on both units/cards - no change.  And I'm not sure if I could do that forcing of speed you show, since I'm not even getting the login prompt...?

The unknown IP is not in our network scheme at all - multiple scans of the config tool did not find anything.  (And this isn't surprising - the card was given to us used, and we run a private but non-standard internal IP range.)  😞  The crossover/Wireshark option may work.  I can give that a try (though I use Wireshark infrequently enough I always feel like I'm starting from scratch every time...:-)  ).  Maybe I'll give that a go this afternoon if I find time to track down/make a crossover.

Thanks!

[BillP · Accepted solution]

Hi Allison - I was thinking to force the baud rate thing on your working AP9619 - see if it allowed you serial access. Understood on the original one you cannot get a log in prompt but I thought via remote command line (telnet/SSH), you may be able to get the second AP9619 going or see if changing the baud rate allowed access to that one.

Hope the Wireshark thing gets you somewhere. If there are any questions you have, let me know and I can see if I can answer based on my experience. I usually just start the capture and connect and see if you see any ARPs happening from the NMC to give you a clue what IP it has.

[Anonymous user]

So yes, Wireshark worked!  So embarrassed I didn't think of that before trying all this serial garbage, to be honest...*SIGH*

Serial still isn't working properly with either card, but if I can get to them over ethernet I don't care in the slightest.  🙂  Thanks again!

[BillP]

Don't be embarrassed! I think you covered a lot of different things to try and that were very logical

Glad you got it all sorted out.