MiniDin9 serial pin outs to talk to DB9 UPS?

MiniDin9 serial pin outs to talk to DB9 UPS?

[Lou Langholtz]

Hello folks,

I'm trying to connect the serial communications up between my PowerMac
7500 and my new BestPower Fortress 1050 UPS to get all the fancy smart
features going but it's not working. Anybody know what I'm doing wrong
or have any ideas? I tried looking again at the macserial.c kernel code
to see if I could make anything out from that but couldn't. Perhaps
someone who know this code better could however. Here's the details...

I'm using the PowerMac 7500 MiniDin9 serial printer port and connecting
it to a DB9 serial connector on my UPS. Unfortunately the setups I've
tried so far don't work. At best, the user and system load go high when
I try and talk with the UPS using the supplied ups terminal program. At
worst, ps hangs and can't be Ctrl-Z or Ctrl-C'd and then the system
can't finish an init 6 reboot without my power-cycling the Mac.
Apparantly the program seems to cycle waiting for something to happen
which I'm guessing needs to be fixed by connecting some other pin(s).

The cable I've made basically connects as follows:

 UPS (DB9)                          PowerMac7500 (MiniDin9)
 pin 1             recieve data     pin 3             TxD-
 pin 2             transmit data    pin 5             RxD-
 pin 4             common           pin 4             Gnd/Shield

The other UPS (DB9) pin outs are:

pin 3: normally open on battery contact
pin 5: normally open low battery alarm
pin 6: plug and play sense for Windows 95
pin 7: remote shutdown
pin 8: normally closed on battery contact
pin 9: unused

The other PowerMac 7500 (MiniDin9) pin outs are (and I had a hard time
finding this info from an Apple web site):

pin 1: SCLK(out)   ---- I'm assuming this is DTR
pin 2: Sync(in)/SCLK(in) ---- I'm assuming this is CTS
pin 6: TxD+
pin 7: Wakeup/TxHS ---- I'm assuming this is DCD
pin 8: RxD+
pin 9: +5V (power to pod) ---- what's a 'pod'?

I was told that the PC serial cable connects similarly sparsely except
that pins 4 and 6 on the PC end are jumpered together. That seems to be
a short between TxD+ and DTR. I tried doing the same for the
Mac MiniDin9 by jumpering MiniDin9 pins 1 and 6 together. This didn't
work. Nor did jumpering 1 to 8 or 1 to 7.

Thanks for any help!     --Lou


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Re: MiniDin9 serial pin outs to talk to DB9 UPS?

[Michael Schmitz]

> The other PowerMac 7500 (MiniDin9) pin outs are (and I had a hard time
> finding this info from an Apple web site):
>
> pin 1: SCLK(out)   ---- I'm assuming this is DTR
> pin 2: Sync(in)/SCLK(in) ---- I'm assuming this is CTS

I recall two pins on the serial port labeled as Handshake in/out which
would translate to RTS/CTS (the other pair is DTR/DSR device status not
handshake). The SCLKs are sync. external clock lines for LocalTalk
perhaps, the Sync would correspond to RI on a modem line.

I'll have to look up the 'standard' pinout for that connector elsewhere
but I recall Apple left out one pin usually needed for hardware
handshaking.

> pin 6: TxD+
> pin 7: Wakeup/TxHS ---- I'm assuming this is DCD
> pin 8: RxD+
> pin 9: +5V (power to pod) ---- what's a 'pod'?
>
> I was told that the PC serial cable connects similarly sparsely except
> that pins 4 and 6 on the PC end are jumpered together. That seems to be
> a short between TxD+ and DTR. I tried doing the same for the

Nope, you need to connect RTS and CTS, and sometimes DTR and DSR and DCD
are also connected together. C onnecting DTR and TxD will only confuse the
serial driver.

> Mac MiniDin9 by jumpering MiniDin9 pins 1 and 6 together. This didn't
> work. Nor did jumpering 1 to 8 or 1 to 7.

Try connecting 1 and 2 ...

	Michael


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Re: MiniDin9 serial pin outs to talk to DB9 UPS?

[Lou Langholtz]

Michael Schmitz wrote:

> . . . Nope, you need to connect RTS and CTS, and sometimes DTR and DSR and
> DCD are also connected together. C onnecting DTR and TxD will only confuse
> the
> serial driver.

>
> > Mac MiniDin9 by jumpering MiniDin9 pins 1 and 6 together. This didn't
> > work. Nor did jumpering 1 to 8 or 1 to 7.
>
> Try connecting 1 and 2 ...
>
>         Michael

Thanks Michael.

I just gave connecting 1 and 2 a try and the results were no better than
before. My UPS terminal program doesn't get anything back from the UPS. It
just sits there spinning waiting for I/O without blocking apparantly as the
user and system loads go up. Of course this UPS terminal program itself may
not be comminicating correctly but at least it compiled without any warnings
(or errors). If communications works correctly the UPS terminal program says
that I should see an output string from the UPS doing something like
identifying itself. I don't see a thing though that appears to come from the
UPS.

Maybe I should jumper one of the other pairs you mention? Maybe I need to
change some stty parameters? Are there any other tools you could suggest to
try talking with the UPS? I haven't tried just using "cat" or "tip" yet. Any
thing obvious that I should avoid? I'll see if I can't drop a serial analyzer
box in the middle some how to see what signalling is actually occuring.

Thanks again. Any one else have any ideas?

--Lou


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Re: MiniDin9 serial pin outs to talk to DB9 UPS?

[Michael Schmitz]

> > > Mac MiniDin9 by jumpering MiniDin9 pins 1 and 6 together. This didn't
> > > work. Nor did jumpering 1 to 8 or 1 to 7.
> >
> > Try connecting 1 and 2 ...
>
> I just gave connecting 1 and 2 a try and the results were no better than
> before. My UPS terminal program doesn't get anything back from the UPS. It
> just sits there spinning waiting for I/O without blocking apparantly as the
> user and system loads go up. Of course this UPS terminal program itself may

The terminal program may not be using long select timeouts or just short
sleeps. On the other end, the DB9 connector may need some pins jumpered.

The good old fashioned LED serial interface monitor may be the best tool
for debugging this :-) Would help to figure out if the UPS sends any data
at all, at least.

> Maybe I should jumper one of the other pairs you mention? Maybe I need to

I'll have to dig out the pinout first. And I'll search for descriptions of
a RS422-RS232 cable (should have come up on linux-mac68k before).

> change some stty parameters? Are there any other tools you could suggest to
> try talking with the UPS? I haven't tried just using "cat" or "tip" yet. Any

cu or minicom is what I use. If the serial port opens at all using those
tools stty should not be needed.

> thing obvious that I should avoid? I'll see if I can't drop a serial analyzer
> box in the middle some how to see what signalling is actually occuring.

That's probably most useful at this point. You'll at least see that the
Mac can send data to the UPS (hopefully) and thus the serial driver
doesn't choke on your wiring.

	Michael


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Re: MiniDin9 serial pin outs to talk to DB9 UPS?

[Mike DeSimone]

>The cable I've made basically connects as follows:
>
> UPS (DB9)                          PowerMac7500 (MiniDin9)
> pin 1             recieve data     pin 3             TxD-
> pin 2             transmit data    pin 5             RxD-
> pin 4             common           pin 4             Gnd/Shield

Assuming the UPS is speaking RS232, you forgot one necessary connection:
RxD+ and Gnd must be connected together on the Mac side.  TxD+ should be
left floating.

>The other UPS (DB9) pin outs are:
>
>pin 3: normally open on battery contact
>pin 5: normally open low battery alarm
>pin 6: plug and play sense for Windows 95
>pin 7: remote shutdown
>pin 8: normally closed on battery contact
>pin 9: unused

Not really a whole lot you can do with these pins without a pullup resistor.

>pin 1: SCLK(out)   ---- I'm assuming this is DTR
>pin 2: Sync(in)/SCLK(in) ---- I'm assuming this is CTS
>pin 6: TxD+
>pin 7: Wakeup/TxHS ---- I'm assuming this is DCD
>pin 8: RxD+

Your assumptions are correct, though I usually see HSKi (handshake in)
instead of CTS, HSKo (handshake out) instead of DTR, and GPI (general
purpose input) instead of DCD.  Functionally, it's all the same, though.

>pin 9: +5V (power to pod) ---- what's a 'pod'?

Apple's GeoPort Telecom Pod.  It was a little box that contained a DSP that
could be programmed to be a modem.  Unfortunately, they didn't expect 56K
modems to get so cheap so fast, so few people bought the pod because it was
so expensive, and couldn't be anything more than a 33.6K or so modem.

In the old days, those serial ports had 8 pins, and you couldn't power
anything from them.  Several third party devices used ADB taps for this
purpose, which was rather kludgy.

>I was told that the PC serial cable connects similarly sparsely except
>that pins 4 and 6 on the PC end are jumpered together. That seems to be
>a short between TxD+ and DTR.

PC ports are RS232, so that jumper is really jumpering DTR and DSR.  Not
needed for the Mac's ports.  Just turn hardware handshaking off.
### Mike DeSimone ### Hot-Wire@mail.utexas.edu ### ares.marsbase.mars ###

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