Serial port on APC Powerstack 450VA ... what comm port settings?

[Anonymous user]

Hi,

We're a nonprofit exerpimental wireless ISP. We recently got 3x APC Powerstack 450VAs on ebay for a price we couldn't pass up. Some of our sites are just wifi radios, so the 280 watt capacity of these old units covers them fine. On other sites where we have servers, we have a few significantly newer modular SmartUPSes. Big fan of the product line.

Anyway, these Powerstack 450VAs have comm ports on the back advertised as RS-232. I've tried with all three units, and in power cycling them I've not found a way to get useful serial output. I can get some random characters at the slower baud rate, but faster yields nothing, and none of the following settings seem to work:

• 115200 8N1
• 57600 8N1
• 38400 8N1
• 19200 8N1
• 9600 8N1
• 4800 8N1
• 2400 8N1

I've tried with a native RS-232 port, an RS-232 USB adapter, and a router with RS-232 port. I'm using one of the Smart UPS RS-232 cables I had on hand from one of our previous SmartUPS units. Sadly, the ops manual doesn't have details on the comm port. A search yielded no results, either.

These units would be fantastic for our low power draw sites, but until we can sort out serial comms they have to sit on the shelf. Advice?

[voidstar_apc]

The tech specs and press release say it supports smart signaling, so unless that means something different from other SmartUPS...

I would try using the cable from the SmartUPS which should have a number on one end: 940-0024C (the last letter doesn't matter). 2400 Baud 8N1. Type uppercase 'Y' a few times.

[Anonymous user]

Hi,

Thank you for the advice. The cable I was trying was 940-1524C. I tried that cable with 2400 8N1 pressing Y multiple times to no effect. I read that the 1524 is the same pinout as the 0024, so this should be the same. Anything else to try? Thanks!

Edit: tried using the other comm port mashing the Y key, and now I get SM back. Press lowercase y and I see (C) APCC.

Great! now time to find documentation as to how this is supposed to be interacted with 🙂

[BillP · Accepted solution]

Software wise, look for our PowerChute Business Edition or third party apcupsd may work nicely for you. This UPS is not intended to be talked to directly most of the time via the Smart Protocol we offer so those softwares I mentioned would ideally be what you use and will save you some time in figuring out manual commands.