[plug] [OT] Maitec Linx UPS Serial Interface

[shayne]

Erm. One real nice way to interface stuff to RS232 is to grab one of
those "basic stamp" pic dingles, hook up a pin via a relay (opto isolate
if you want to be really kind to your gear) and then an rs232 outa a
couple of pins

Ie.

+5------+----------------------+ +-------240 in being monitored
        |  _____________       | |
        +--|           |       RELAY 
           |           |-------+ |
0v----+----|           |         +-------240 out being monitored
      |    |           |
RS232 |    |  BS 1     |                  Even nicer if dc voltage
GND---+    |           |                  is used for monitoring
           |           |
PC's RX----|           |
           +-----------+

The schematic is *slightly* more complex than that, and I don't
know enuff bout analog to know if the signal would need to be 
DC rectified to make the relay work.(Probly other ways of doing
this) but yeah, fiddle with this tech... Those basic stamps are 
Verry cool lowend way of making one off pc interfaces.The beauty
is then you can use the remaning pins on the basic stamp to be either
other monitors, or alternatively control pins to turn stuff on or off.

Erm either way, you really need at least a TTL level signal to make a
serial port take notice. the floating range for RS232 is theoretically
+-3v from memory. You can probably also use RTS/CTS like that. Where I
used to work we did quite a lot of RS232 interfacing, and I tell ya, 
what those pins mean really depends on what random mood the manufacturer
was that day. The three pin + - GND combo was all RS232 shoulda ever
had. Handshakings for wimps!

Shayne.

On Tue, 2002-10-29 at 16:23, ryan at is.as.geeky.as wrote:
> With all the recentish talk of UPS equipment I finally got out the ratchet
> crimper and constructed the 192VDC battery packs (16x12V SLA batteries in
> series) needed for 2 lovely old Maitec Linx UPS units I bought a while ago .
> If anyone doesn't know what they are, they used to be manufactured many many
> years ago in NSW, have top to bottom heatsinks front and back, provide
> full-time mains isolation, allow battery-only invertor starting and just
> simply work like a charm.
> 
> Now down to business.  Has anyone every touched one of these units,
> particularly with regards to the serial interface?  There is an empty
> 'interface' module socket inside with all the other modules such as boost,
> control, synch/byp and inverter but I'm not sure if this is needed for
> serial communications or not.  There is a 9 pin serial port on the back of
> the 800 unit but not the 1400.  All attempts to coax information out of the
> serial port have failed - as have the same attempts on the one with no
> serial port :)
> 
> This page: http://www.emulab.ee.mu.oz.au/~mick/Personal/UPS/index.html talks
> of the 1500 (different to my 800 and 1400) and suggests it has some form of
> mini terminal server in it .. i doubt mi> Alternatively I can find a 'nicely marked' mains-bypass output and make the
> serial port take whatever pin I desire high/low when the mains fail - if I
> did that, can such a signal be detected on a serial port in Linux, or does
> actual data need to flow rather than jus> Alternatively I can find a 'nicely marked' mains-bypass output and make the
> serial port take whatever pin I desire high/low when the mains fail - if I
> did that, can such a signal be detected on a serial port in Linux, or does
> actual data need to flow rather than just a simple high/low pin?   The
> DTR/CD lines works like that on an RS232 port don't they?  Could that be
> detected easily?
> 
> Anyone got a clue about any of this?
> 
> Ryan
> 
t a simple high/low pin?   The
> DTR/CD lines works like that on an RS232 port don't they?  Could that be
> detected easily?
> 
> Anyone got a clue about any of this?
> 
> Ryan
> 
ne are this advanced.
> 
> Alternatively I can find a 'nicely marked' mains-bypass output and make the
> serial port take whatever pin I desire high/low when the mains fail - if I
> did that, can such a signal be detected on a serial port in Linux, or does
> actual data need to flow rather than just a simple high/low pin?   The
> DTR/CD lines works like that on an RS232 port don't they?  Could that be
> detected easily?
> 
> Anyone got a clue about any of this?
> 
> Ryan
>