SMT1500C and loss of USB connection?

Psychor · ‎2021-08-28

I just purchase a new SMT1500C. I have it connected to the Internet and connected to my PC via USB. I installed PCBE v10.0.02 on my PC to communicate with the UPS via USB.

If I disconnect and reconnect the USB cable the APC will be detected by PowerChute. But within a few minutes PowerChute will report a lost connection with the APC. The only way to fix this it to disconnect and reconnect the cable again. I tried connecting the USB cable to different ports on my PC.

I've looked this up via the Internet and this appears to be a common issue for other APC UPS owners. I didn't expect this to be an issue with their latest SMT series.

Does anyone know what's going on here? I've owned many SUA and SMT units and I've never had this issue.

Thank you.

Psychor · ‎2021-08-30

So what I've found is that if you go under Device Manager and manually change the UPS APC driver to "HID UPS Battery" Windows will at least let you manage the UPS. However, this means that you can no longer use PowerChute as that requires a specific APC driver.

This is not an ideal fix. APC really needs to figure out what's going on with their USB hardware and/or their driver. But based on the above solution it leads me to believe the issue is more with their USB driver.

Psychor · ‎2021-09-05

@Psychor wrote:
So what I've found is that if you go under Device Manager and manually change the UPS APC driver to "HID UPS Battery" Windows will at least let you manage the UPS. However, this means that you can no longer use PowerChute as that requires a specific APC driver.

This is not an ideal fix. APC really needs to figure out what's going on with their USB hardware and/or their driver. But based on the above solution it leads me to believe the issue is more with their USB driver.

So I thought this was a valid workaround, bit it isn't. Windows will see the UPS, but think's you're on a laptop instead of a desktop. It keeps sending my desktop into sleep mode due to "low battery" warnings even though the UPS is at 98% battery.

I've been waiting over a week to hear from APC on this matter. 😐

BillP · ‎2021-09-07

@Psychor

What firmware is the SMT1500C running? You will find the firmware information via the LCD panel under About, UPS Firmware.

As for the computer going to sleep, what are the battery setting? Go to Control Panel, Power Options, Advanced Settings.

Psychor · ‎2021-09-14

@BillP wrote:
@Psychor

What firmware is the SMT1500C running? You will find the firmware information via the LCD panel under About, UPS Firmware.

As for the computer going to sleep, what are the battery setting? Go to Control Panel, Power Options, Advanced Settings.

@BillP,

I can only access the Windows battery configuration screen for the APC if I switch the USB driver within Windows to the generic Windows USB driver. If I use the APC USB driver the screen you display is disabled by Windows and you have to use PowerChute. However, I should be able to use PowerChute and not continue to have my USB connection drop.

APC sent me a second new SMT1500C. Both units shipped with firmware version 0.41. Both units do the exact same thing. Communication between the APC and PC, via USB, will work when first connecting the units and then the USB connection will randomly be lost. If I remove the USB cable and reconnect it connection between the APC and PC will be reestablish for a time and then it will drop out again.

It doesn't matter what USB port I use on my PC. I even posted a video of the issue below.

I really wish you all could forward this to the engineering team. This is an issue all over the APC forum.

Psychor · ‎2021-09-14

So I can replicate the exact same issue on two band new APC UPS SMT1500C units. It doesn't matter what USB port I use on my PC - old (2) or new (3). But this issue isn't unique to me... people have posted this same exact issue on this forum for years. 😑

I even captured a video of the issue occurring. I installed a fresh copy of the latest version of PowerChute Business for Windows with the UPS connected to my PC via USB. All went well and the UPS was detected. I navigated PowerChute for a little over a minute and around the 1:08 minute mark you can clearly see the USB connection randomly being lost.

https://youtu.be/kP_JEPXnyHY

Something is either wrong with the APC USB controller or their APC USB driver - maybe both.

If I connect my APC to my PC via a serial RJ45 to USB cable the UPS doesn't lose it's connection - go figure.

This is ridiculous!!!

BillP · ‎2021-09-15

@Psychor

Would you turn off Green Mode on the UPS. Then install PowerChute using USB comm and report back? To turn off Green Mode from the UPS LCD panel go to, Configuration, Green Mode, press enter, press the up or down arrow to change from Enabled to Disabled, press enter to save the setting.

Psychor · ‎2021-09-15

@BillP wrote:
@Psychor

Would you turn off Green Mode on the UPS. Then install PowerChute using USB comm and report back? To turn off Green Mode from the UPS LCD panel go to, Configuration, Green Mode, press enter, press the up or down arrow to change from Enabled to Disabled, press enter to save the setting.

Thanks for the suggestion, but it made no difference.

Vorlon13 · ‎2022-01-07

Hello @Psychor ,

As i have exactly the same problem with my SMT1500 unit, did you find any solution to the loss of USB connection?

BillP · ‎2022-01-10

@Psychor

From the LCD panel of the UPS, scroll to Configuration - Green Mode and disable Green Mode. Then hold the Up and Down arrows for 5 to 6 seconds. The UPS communications bus will reset. The UPS will provide output during the reset, so you do not need to power anything off. Once reset, install PowerChute. The UPS and system should communicate.

Psychor · ‎2022-01-10

No. Though APC is aware of the issue. They had me run some test program to gather logs and I was told they're working on it. It's my hope that they actually are doing so.

I'm glad that more people are posting here to show that the issue is NOT in fact our computers, but the APC UPS itself.

BillP · ‎2022-01-12

@Psychor

Does the APC UPS battery driver load when PowerChute is installed as explained in FAQ FA164514?

Psychor · ‎2022-01-12

@BillP, we've been working together directly via email and phone. 😁

Mind posting a link here though just in case this is something new we haven't tried?

Frozen · ‎2022-02-02

Hello Psychor
I'm wondering if "serial RJ45 to USB cable the UPS" communication works normally?
We have been using apc ups in our company for years and there is a constant problem with interrupting communication via usb-usb.
UPS is powered by a computer that runs a large cooling system. It has already happened that the ups went out and consequently the cooling system stopped and intervention was needed.

Thx