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February 28th, 2022 03:00

UPS Communication Error

Hello

I've connected our Dell 3750W UPS to an ESXi host via a USB2.0 cable. After installing the Dell MUMC application, the UPS is detected but reports 'Communication with device has failed'. 

It's definitely configured correctly on the virtual machine as device manager detects the UPS. I have other UPS's in other cabinets connected in the same way with no issues.

I've tried both the MUMC and ULNM software with the same result on both. I also connected the UPS directly to my laptop to test it with the MUMC installed which seemed to work correctly, which suggests something on my VM or host that isn't right, not the UPS or cable.

Can anyone help with this as I'm running out of ideas.  

Inked2022-02-28 11_26_55- Remote Desktop Connection.jpg

Inked2022-02-28 11_27_27- Remote Desktop Connection.jpg

Thanks

Moderator

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8.4K Posts

February 28th, 2022 07:00

NGUK Support,

 

I would start by verifying the UPS is up to date on any firmware updates. Then I would take a look at this post, as it goes over communications errors with MUMC, and verify the ports that are listed as well.

 

Let me know what you see. 

 

 

 

March 1st, 2022 05:00

Hi Chris

I tried using the Firmware Update Tool but that was also unable to connect to the UPS.

I checked the post you provided the link to but it seems to refer to a different problem to mine. The problem I have is that the MUMC cannot communicate with the UPS. It detects that something is there but cannot properly see it.

Thanks

Moderator

 • 

8.4K Posts

March 1st, 2022 08:00

I apologize, if you follow this link on page 14 is the ports list used by MUMC, would you verify if they are configured correctly?

 

 

March 2nd, 2022 03:00

Hi Chris

I've made sure all those ports are open on our firewall. I even tried disabling Windows Firewall entirely and it made no difference. The UPS still shows as 'Communication with device has failed'

Thanks

Moderator

 • 

278 Posts

March 2nd, 2022 07:00

Hello NGUK Support,

 

I am sorry you faced with this issue.

 

Did you try other USB2.0 cable?

Is there error information on the UPS status screen?

UPS status screen you can check here:

 

https://dell.to/34cgws0 p.36

 

What version of Dell UPS ULNM and MUMC Management Software is installed?

 

Thanks,

March 2nd, 2022 23:00

Hi Maria

I've tried 2 different cables with the same problem. The cable that's currently connected is the one that I tried directly on my laptop and confirmed that it works.

There are no errors on the screen on the UPS. It shows that it's operating in 'Normal Mode'

I have MUMC 1.08.0015 installed on a server running Windows Server 2016 Standard.

Thanks

Moderator

 • 

278 Posts

March 3rd, 2022 04:00

Hello NGUK Support,

 

Thanks you for your reply. I've checked several documents and technical articles and I could suggest follow:

In case status of UPS is 'Normal Mode' we can exclude hardware issue at the moment.

 

In Dell UPS Management Software - VMware vCenter Shutdown Scenarios guide I found follow information:

 

UPS communications: The Dell UPS must be connected to an IP network using the optional Dell

Network Management Card (NMC). USB communications are not supported for the

virtualized “Agentless” applications discussed in this document.

 

Survivable network connectivity: The MUMC client must retain IP communications with both the UPS

and vCenter at all times. Take care to ensure that network switches and other networking equipment

are covered by UPS protection and suitable redundancy built into the network. If network connectivity is considered a weak link in the architecture, the optional ULNM agent can be installed on the local ESXi host to act as a local shutdown agent that can take action even when connectivity to the main MUMC client has been lost. This approach is not discussed in this document.

 

https://dell.to/3Kgmt6G p.8

 

Figure 3: Dell UPS management software connectivity scenarios:

 

https://dell.to/3Kgmt6G p.6

 

Could you please check this connectivity scenarios, which one do you have? Is it Agentless?

Please let me know if you have any questions,

 

Thanks.

March 3rd, 2022 05:00

Hi Maria

I believe it is the 'Agentless' installation. What I don't understand is that I have this exact same setup with 2 other UPSs on a different host and they work fine. The 2 UPSs are connected to the host using USB 2.0 cables.

NGUKSupport_0-1646315272492.png

I also tried setting up the MUMC software on a different VM on this same host and it still has the same issue. It seems there's something on this host that's not working correctly. As I mentioned earlier, the device manager shows the UPS is connected, but the MUMC software cannot see it properly.

NGUKSupport_1-1646315299943.png

 

Thanks

Moderator

 • 

8.4K Posts

March 3rd, 2022 06:00

NGUK Support,

 

I would start by looking at the differences between the two working and this one, specifically firmware revisions, BIOS, etc. 

Maria was correct, where it doesn't look to support USB, and that the hardware seems to be ok currently, so I would look at if it might be due to a specific firmware revision.

 

 

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