APC UPS won't talk to me

[notme]

On Thu, 23 Jul 2009 13:50:27 -0700, Andrew Rossmann wrote
(in article <MPG.24d2890c122f253498968e@news.eternal-september.org&gt:

To add in: Many of the basic APC UPS's don't use true serial
communications. They just use some of the control lines to signify power
out, low battery, and to signal the UPS to do a shutdown. I don't know
if it will work correctly through a USB-to-serial adapter.

This has been said a few times here. Until I get a breakout box and look at a
few of the lines on that connector to see if it's actually data or just
pulling lines high or low, I won't know.

My work computer has a BP650M with a self-made cable. It's just a
standard 9-pin serial cable, but the UPS end is slightly rewired, and I
think there is also a resistor. It's just using the stock Win2K support.

I know that APC says that a standard serial cable won't work. I'm using their
p/n cable that came with the UPS.

Thanks for your input.

 

[Thomas Tornblom]

I recommend you check out:

http://www.apcupsd.com/

I tried to get APC:s software to run on a Solaris x86 system, but gave
up. apcupsd works fine, even through a prolific based usb-serial
adapter.

I haven't tried it on MacOS though.

I have an APC Smart UPS 700, which speaks serial, not some status port
wiggle. It does require a APC specific cable though.

The link above contains references to simple commands that can be
issued through a terminal emulator to verify that the communication
works.

 

[petrus bitbyter]

"notme" <notme@notme.org> schreef in bericht
news:0001HW.C68DCC3E0050284EB08A39AF@news.eternal-september.org...

On Thu, 23 Jul 2009 03:45:10 -0700, petrus bitbyter wrote
(in article <4a683f3f$0$10060$e4fe514c@dreader13.news.xs4all.nl&gt:

FAIK APC UPS communication should be started by sending a question mark
to
it.

petrus bitbyter

For troubleshooting purposes, what settings should the terminal program
use?
- VT100 or PC-ANSI?
- High bit stripped?
- Drop DTR on exit?
- Auto line-feed?

Thanks.

First: I was mistaken about the question mark. You should send a Y.

You should use a normal ANSI terminal set to: 2400,n,8,1

APC is known for using non-standard cables. The one I saw had the next
connections:

PC(DE9F) UPS(DE9M)
2------------------2
3------------------1
5------------------9
1-4
7-8

But there sure are other ones depending on the UPS-type. This one is for the
APC Smart UPSs.
No need to say there's no hardware handshake in this one.

But... Does your UPS talk RS232 anyway? I seem to remember that BackupPro
types are rather dumb things that only do some signaling i.e. using pin 2 to
tell the UPS is on battery. Guess on the PC side this should be considered a
"break" and that's all.

petrus bitbyter

 

[notme]

On Thu, 23 Jul 2009 14:24:01 -0700, Thomas Tornblom wrote
(in article <x0k51zccur.fsf@Hax.SE&gt:

http://www.apcupsd.com/

Thanks for that. A great resource for APC owners who want to hack the device.


The commands you speak of are commands sent through the apcupsd daemon, not
thorough a terminal program. Building the daemon for OS X and installing it
is a (to me) monumental task.

But I think joining the support mailing list could prove helpful.

Thanks again.

 

[notme]

On Thu, 23 Jul 2009 14:24:01 -0700, Thomas Tornblom wrote
(in article <x0k51zccur.fsf@Hax.SE&gt:

http://www.apcupsd.com/

This site has much information about communication with the APC UPS's.

This is a diagram of the cable that came with my Backup-Pro UPS 650 (model
BP650S):

APC Part# - 940-0095B
Signal Computer UPS
DB9F DB9M
DTR 4 ----*
CTS 8 ----|
DSR 6 ----|
DCD 1 ----*
GND 5 ---------------*---- 4 Ground
|
*---- 9 Common
RI 9 ----*
|
RxD 2 ----*--------------- 2 On Battery
TxD 3 ----------[####]---- 1 Kill UPS Power
4.7K ohm

Apparently it uses voltage-level signaling not serial communication.

But I see no reason this won't work via a USB-serial adapter. When the RxD or
TxD line is brought low, a bit is set or cleared in the buffer in the
USB-serial driver.

It's a whole other story whether OS X will recognize such signals.

Why wouldn't this work with the USB-serial adapter?

Thanks.

 

[Robert Baer]

notme wrote:

So you know the cable is OK via APC support .AND. that loopback works OK.
Loopback working OK also indicates that at least that part of the
converter is working properly.
So, take a small step of faith and assume the whole converter can
work OK (ie: nothing wrong with it).
Therefore, it is the software: either the USB driver (most likely)

If data is going out and coming in, that means the USB driver works. Yes?
** Good point; YES would be the logical conclusion.

or the application.

It's not a stand-alone app. It's part of the System Preferences of Mac OS X.

And Googling a bit, I've seen no evidence that the UPS monitoring feature has
been an issue with other models of UPS.

So, I suspect it's a non-standard spec of the APC UPS communication spec for
this model. Worst case.
** Seems that is what is left, Mr. Occam.

N.

 

In article <MPG.24d2890c122f253498968e@news.eternal-september.org>, Andrew Rossmann <andysnewsreply@no_junk.comcast.net> writes:

In article <0001HW.C68D4EA00032B730B08A39AF@news.eternal-september.org>,
notme@notme.org says...
[Re-posted with new subject and more appropriate NG's)

Using a USB-to-Serial adapter to connect a laptop to APC UPS' RS232 serial
port.

No signs of communication from the UPS. The laptop's OS has an
auto-recognition feature that enables built-in power-down options if/when the
UPS communicates its presence.

To add in: Many of the basic APC UPS's don't use true serial
communications. They just use some of the control lines to signify power
out, low battery, and to signal the UPS to do a shutdown. I don't know
if it will work correctly through a USB-to-serial adapter.

My work computer has a BP650M with a self-made cable. It's just a
standard 9-pin serial cable, but the UPS end is slightly rewired, and I
think there is also a resistor. It's just using the stock Win2K support.

That's correct. The basic model simply toggle the equivalent of DTR high
or log to signal that the UPS is or is not providing power from battery.

An AC UPS that speaks their (not so incredibly) "Smart" prototcol, namely
the SmartUPS and more expensive APC UPS options, uses a serial cable that
is wired:

APC UPS
1 <==> 3
2 <==> 2
9 <==> 5

In fact, if you plug in a standard, full-signal, 9 pin cable to both the
APC and CPU, you run the risk of powering down the APC real fast.

FWIW, I sell an APC US solution in the OpenVMS space. I have seen this
communications problem with APC UPSs all too many times.

--
VAXman- A Bored Certified VMS Kernel Mode Hacker VAXman(at)TMESIS(dot)ORG

http://www.quirkfactory.com/popart/asskey/eqn2.png

"Well my son, life is like a beanstalk, isn't it?"

 

[Jasen Betts]

On 2009-07-23, Nobody <nobody@nowhere.com> wrote:

On Wed, 22 Jul 2009 23:17:52 -0700, notme wrote:

[Re-posted with new subject and more appropriate NG's)

Using a USB-to-Serial adapter to connect a laptop to APC UPS' RS232 serial
port.

No signs of communication from the UPS. The laptop's OS has an
auto-recognition feature that enables built-in power-down options if/when the
UPS communicates its presence.

Ideas?

UPSes don't normally speak serial. More often, they simply connect two
pins together, treating the serial port as a general-purpose I/O port.
This won't work with a USB-to-serial converter, as there is no serial data
to convert.

yeah it will, usb-to-serial adaptors duplicate the same modem control
pins and signals, applications that don't do direct IO port access
will work just fine on usb-serial adaptors.

I did that myself last month.

 

[JosephKK]

On Thu, 23 Jul 2009 11:43:34 +0100, Nobody <nobody@nowhere.com> wrote:

On Wed, 22 Jul 2009 23:17:52 -0700, notme wrote:

[Re-posted with new subject and more appropriate NG's)

Using a USB-to-Serial adapter to connect a laptop to APC UPS' RS232 serial
port.

No signs of communication from the UPS. The laptop's OS has an
auto-recognition feature that enables built-in power-down options if/when the
UPS communicates its presence.

Ideas?

UPSes don't normally speak serial. More often, they simply connect two
pins together, treating the serial port as a general-purpose I/O port.
This won't work with a USB-to-serial converter, as there is no serial data
to convert.

I have seen UPSs that talk contact closures, EIA-232, EIA-485, and
even Ethernet. It varies by make model and options. I have seen them
in power ranges from 50 W to 500,000 W with appropriate VA and surge
ratings.

 

[Jeroni Paul]

On 24 Jul, 05:09, notme <no...@notme.org> wrote:

Apparently it uses voltage-level signaling not serial communication.

But I see no reason this won't work via a USB-serial adapter. When the RxD or
TxD line is brought low, a bit is set or cleared in the buffer in the
USB-serial driver.

It's a whole other story whether OS X will recognize such signals.

Why wouldn't this work with the USB-serial adapter?

These converters are known to cause trouble if used with anything
other than standard terminal communication. They might be designed for
data transfer only or they might add a delay in the signals that
causes havoc. Anyway they were useless to use chip programmers on
laptops without serial port.

 

[Nobody]

On Thu, 23 Jul 2009 20:09:16 -0700, notme wrote:

Apparently it uses voltage-level signaling not serial communication.

But I see no reason this won't work via a USB-serial adapter. When the RxD or
TxD line is brought low, a bit is set or cleared in the buffer in the
USB-serial driver.

A USB-to-serial-adaptor is not a DAQ interface. It doesn't simply send a
stream of pin states or state-change events directly to the host.

A typical USB-to-serial adaptor[1] will expect a sequence consisting of a
start bit, 8 data bits, an optional parity bit and 1 or 2 stop bits, all
occurring at the configured (or auto-detected) baud rate.

[1] CDC, ACM = Communication Device Class, Abstract Control Model.

When it sees such a signal (IOW, when the UART says "a byte has been
received"), it will queue the the received byte to be sent to the host.

It may also inform the host if the control lines (DCD, DSR, RI) change,
but this feature (SERIAL_STATE notification) is optional.

Based upon your wiring diagram, if you can find a USB-to-serial adaptor
which supports the Ring Indicator (RI) line, you should be okay. Or if you
can find one which supports DSR or DCD, you can make your own cable which
uses this line instead.

You may have better luck with DSR or DCD. RI is the least useful signal,
as you can just have the modem driver listen for a "RING" response from
the modem. If the RS-232 driver is 4-in-4-out (e.g. MAX238), it's likely
that RI is the one which will be ignored.

Also, note that you can't directly query the state of CTS (the device just
NAKs Tx packets if the Tx buffer is full), so if the RS-232 driver is
2-in-2-out (e.g. MAX232), you're out of luck, as none of DCD, DSR or RI
will be monitored.

FWIW, the USB CDC specification is at:

http://www.usb.org/developers/devclass_docs/usbcdc11.pdf

 

do you have PowerChute installed??????

I had this problem on a windows system.

I think it had to do with a setting in Powerchute OR in the UPS
interface settings of windows.

There was a place to set a rising or falling signal - either pos or
neg logic.

if the comm is working I suspect this is the issue.

I think the OS just looks for a logic change and runs the shutdown
from there. The UPS doesn't actually send code to the OS just a logic
change.

Windows shows an APC UPS attached in device manager. If MAC has a
similar function it should show that to otherwise it won't know what
to do with the signal.

It was a long time ago and memory is foggy so take it as a hint.